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International audience; Considerable progress has been made in the nutritional modelling of growth. Most models typically predict (or analyse) the response of a single animal, However, the response to nutrients of a single, representative animal is likely to be different from the response of the herd. To address the variation in response between animals, a stochastic approach towards nutritional modelling is required. In the present study, an analysis method is presented to describe growth and feed intake curves of individual pigs within a population of 192 pigs. This method was developed to allow end-users of InraPorc (a nutritional model predicting and analysing growth in pigs) to easily characterise their animals based on observed data and then use the model to test different scenarios. First, growth and intake data were curve-fitted to characterise individual pigs in terms of BW (Gompertz function of age) and feed intake (power function of BW) by a set of five parameters, having a biological or technico-economical meaning. This information was then used to create a population of virtual pigs in InraPorc, having the same feed intake and growth characteristics as those observed in the population. After determination of the mean lysine (Lys) requirement curve of the population, simulations were carried out for each virtual pig using different feeding strategies (i.e. 1, 2, 3 or 10 diets) and Lys supply (ranging from 70% to 130% of the mean requirement of the population). Because of the phenotypic variation between pigs and the common feeding strategies that were applied to the population, the Lys requirement of each individual pig was not always met. The percentage of pigs for which the Lys requirement was met increased concomitantly with increasing Lys supply, but decreased with increasing number of diets used. Simulated daily gain increased and feed conversion ratio decreased with increasing Lys supply (P < 0.001) according to a curvilinear-plateau relationship. Simulated performance was close to maximum when the Lys supply was 110% of the mean population requirement and did not depend on the number of diets used. At this level of Lys supply, the coefficient of variation of simulated daily gain was minimal and close to 10%, which appears to be a phenotypic characteristic of this population. At lower Lys supplies, simulated performance decreased and variability of daily gain increased with an increasing number of diets (P < 0.001). Knowledge of nutrient requirements becomes more critical when a greater number of diets are used. This study shows the limitations of using a deterministic model to estimate the nutrient requirements of a population of pigs. A stochastic approach can be used provided that relationships between the most relevant model parameters are known.

Twelve Arabidopsis accessions were challenged with Plum pox potyvirus (PPV) isolates representative of the four PPV strains. Each accession supported local and systemic infection by at least some of the PPV isolates, but high variability was observed in the behavior of the five PPV isolates or the 12 Arabidopsis accessions. Resistance to local infection or long-distance movement occurred in about 40% of all the accession-isolate combinations analyzed. Except for Nd-1, all accessions showed resistance to local infection by PPV-SoC; in the Landsberg erecta (Ler) accession, this resistance was compromised by sgt1 and rar1 mutations, suggesting that it could be controlled by an R gene-mediated resistance pathway. While most of the susceptible accessions were symptomless, PPV induced severe symptoms on inflorescences in C24, Ler, and Bay-0 as early as 15 days after inoculation. Genetic analyses indicated that these interaction phenotypes are controlled by different genetic systems. The restriction of long-distance movement of PPV-El Amar and of another member of genus Potyvirus, Lettuce mosaic virus, in Col-0 requires the RTM genes, indicating for the first time that the RTM system may provide a broad range, potyvirus-specific protection against systemic infection. The restriction to PPVPS long-distance movement in Cvi-1 is controlled by a single recessive gene, designated rpv1, which was mapped to chromosome 1. The nuclear inclusion polymerase b-capsid protein region of the viral genome appears to be responsible for the ability of PPV-R to overcome rpv1-mediated resistance.

International audience; This paper focuses on the modeling of the variability of some properties in Sessile oak wood (five swelling coefficients and wood density). They are modeled with linear mixed models. The data have a seven-levels hierarchical organization. The variability at each level is modeled with a variance matrix. Unfortunately, a model with all variances has too many parameters to be usable, so preferably only one variance other than the residual is kept. A graphical procedure based on the comparison of residual variance in the different candidate models is used to detect this main level. Result shows that the main level of variability is the "tree" level or the "height within tree" level for five properties. We cannot conclude for the last property. For other properties, the residual variance in the model with a "tree effect" is reduced to 40% of the residual variance of the model without structuring of variability. If the applications of models deal with the variability of properties, this "tree level" cannot be neglected.; Simplifier un modèle mixte destiné à effectuer des simulations lorsque les données ont une structure hiérarchique complexe. Exemple de quelques propriétés de base du bois de Chêne sessile (Quercus petraea Liebl.). Cet article traite de la modélisation de la variabilité de propriétés du bois de Chêne sessile (cinq coefficients de gonflement et la densité du bois). Ces propriétés sont modélisées à l'aide de modèles linéaires mixtes. Les données ont une organisation hiérarchique à sept niveaux. La variabilité à chacun de ces niveaux est modélisée par une matrice de variance. Cependant, le modèle avec toutes les variances comprend trop de paramètres pour être utilisable, aussi le choix est fait de ne tenir compte que d'une seule variance en plus de la variance résiduelle. On utilise une procédure graphique basée sur la comparaison des variances résiduelles des différents modèles candidats pour détecter le niveau principal de la variabilité. Ce niveau principal est ainsi le niveau " arbre " ou le niveau " hauteur dans l'arbre " pour cinq des propriétés. On ne peut pas conclure pour la sixième. Pour toutes les autres propriétés, la prise en compte d'un effet arbre permet de réduire la variance résiduelle à 40 % de la valeur obtenue dans un modèle sans structuration de la variabilité. Si la variabilité des propriétés est un facteur important pour les applications des modèles, ce niveau " arbre " ne peut pas être négligé.

The aim of this work was to analyse the phenological variation of a residual invasive semi-evergreen shrub in Sahelian fallows in Niger. This species, Guiera senegalensis (Combretaceae), has benefited from the elimination of other species thanks to its high resistance to the increasing cutting pressure for cultivation. We sought to identify traits of its life cycle that could contribute to its persistence and widespread dominance under such a disturbance regime. Leafing, flowering and fruiting were monitored on seven fallows differing in topographic location, age, shrub density and degradation state, during two rainy seasons and one dry season. Phenological spectra showed similar timing of the three phenophases of the seven populations. Differences were observed mainly in magnitude of the phases. However, there were both a high intra-fallow variability (64.6% of the whole variability) and a statistically significant inter-fallow variability, despite only 35.4% of the total variability being due to differences between fallows. A statistical classification of the fallows was proposed based on shrub phenological course over the two cycles monitored. This classification corresponds to a gradient of life-cycle achievement primarily linked to the topographic situation of the stations, and then to a combination of other factors. The flexibility of the phenology at the individual, population and metapopulation scales, inherent to its specific semi-evergreenness property, appeared as an essential phenological attribute contributing to successful widespread persistence of G. senegalensis in the study area.

Inheritance of the ovulation rate (OR) in the Lacaune meat breed was studied through records from a small nucleus of 36 hyper-prolific ewes screened on farms on the basis of their natural litter size, and from progeny data of three selected Lacaune sires. These sires were chosen at the AI centre according to their breeding values estimated for the mean and the variability of their daughters' litter size. Non-carrier Lacaune dairy ewes were inseminated to produce 121 F1 daughters and 27 F1 sons. Twelve sons (four from each sire) were used in turn to inseminate non-carrier Lacaune dairy ewes providing 260 BC progeny ewes. F1 and BC progeny were brought from private farms and gathered after weaning on an experimental farm where ovulation rates were recorded in the first and second breeding seasons. With an average of 6.5 records each, the mean OR of hyper-prolific ewes was very high (5.34), and 38.4% of records showed a rate of 6 or more. F1 data showed high repeatability of OR (r = 0.54) within ewe, with significant variability among ewes. High OR (≥ 4) were observed in each family. A segregation analysis provided a significant likelihood ratio and classified the three founders as heterozygous. BC ewes also displayed high repeatability of OR (r = 0.47) and the mean OR varied considerably between families (from 1.24 to 1.78). Seven of the 12 BC families presented high-ovulating ewes (at least one record ≥ 4) and segregation analysis yielded a highly significant likelihood ratio as compared to an empirical test distribution. The high variability of the mean ovulation rate shown by a small group of daughters of BC ewes inseminated by putative carrier F1 rams, and the very high ovulation rate observed for some of these ewe lambs, confirmed the segregation of a major gene with two co-dominant alleles borne by an autosome. The difference between homozygous non-carriers and heterozygous ewes was about one ovulation on the observed scale and 2.2 standard deviations on the underlying scale.

We have constructed a common bean genomic library enriched for microsatellite motifs (ATA), (CA), (CAC) and (GA). After screening, 60% of the clones selected from the library enriched for the (ATA) repeat contained microsatellites versus 21% of the clones from the library enriched for (GA) (CA) and (CAC) repeats. Fifteen primer pairs have been developed allowing for the amplification of SSR loci. We have evaluated the genetic diversity of these loci between 45 different bean lines belonging to nine various quality types. A total of 81 alleles were detected at the 15 microsatellite loci with an average of 5.3 alleles per locus. We have investigated the origin of allelic size polymorphism at the locus PvATA20 in which the number of repeats ranges from 24 to 85. We have related these large differences in repeat number to unequal crossing-over between repeated DNA regions. The diversity analysis revealed contrasted levels of variability according to the bean type. The lower level was evidenced for the very fine French bean, showing the effect of breeders intensive selection.

International audience; This paper deals with the variability of moisture induced movements in Norway spruce wood. Totally 987 specimens from 12 well defined trees, six from a fast-grown and six from a slow-grown stand, were studied in detail. A large variation in moisture induced movements was found. The swelling coefficients in the longitudinal direction ($\alpha_{\rm l}$) varied between 0.001 and 0.035, in the tangential direction ($\alpha_{\rm t}$) between 0.18 and 0.46 and in the radial direction ($\alpha_{\rm r}$) between 0.07 and 0.28. Especially for $\alpha_{\rm l}$ there was an individual variation with distance from the pith for each of the studied trees. For $\alpha_{\rm t}$ and $\alpha_{\rm r}$ there was a difference between the trees but no clear variation with distance from the pith. By excluding specimens containing knots and/or compression wood, the variability in swelling coefficients was decreased, especially for $\alpha_{\rm l}$. The eigenfrequency in the longitudinal direction was the single best parameter, measured in this study, to predict swelling coefficients in all three directions. The variation in eigenfrequency explained 52% of the variations in $\alpha_{\rm l}$, 67% of the variations in $\alpha_{\rm t}$ and 52% of the variations in $\alpha_{\rm r}$. Specimens from the fast-grown stand and specimens containing compression wood were less anisotropic than the other specimens.; Variation des mouvements induits par l'humidité dans l'Épicéa (Picea abies). Ce papier traite de la variabilité des mouvements induits par l'humidité dans le bois d'Épicéa. En tout 987 échantillons provenant de 12 arbres bien identifiés, 6 d'un site à croissance rapide et 6 d'un site à croissance lente, ont été étudiés en détail. Une variation importante des mouvements induits par l'humidité a été trouvée. Le coefficient de gonflement (exprimé en % de déformation par % de variation d'humidité du bois) dans la direction longitudinale ($\alpha_{\rm l}$) varie entre 0.001 et 0.035, celui de la direction tangentielle ($\alpha_{\rm t}$) entre 0.18 et 0.46, celui de la direction radiale ($\alpha_{\rm r}$) entre 0.07 et 0.28. Dans le cas de al une variation individuelle avec la distance à la moelle a été constatée pour chacun des arbres étudiés. Pour $\alpha_{\rm t}$ et $\alpha_{\rm r}$ il y a une différence entre les arbres mais pas de variation nette en fonction de la distance à la moelle. En excluant les échantillons contenant des nœuds et/ou du bois de compression, on diminue la variabilité du coefficient de gonflement, spécialement pour $\alpha_{\rm l}$. Dans cette étude, le seul paramètre explicatif des coefficients de gonflement dans les trois directions était la fréquence de résonance dans un essai de vibration dans la direction longitudinale. Les variations de cette fréquence de résonance expliquent 52 % des variations de $\alpha_{\rm l}$, 67 % de celles de $\alpha_{\rm t}$, 52 % de celles de $\alpha_{\rm r}$. Les échantillons provenant du site à croissance rapide et ceux contenant du bois de compression étaient moins anisotropes que les autres échantillons.

International audience; Foot-and-mouth disease virus (FMDV) was the first animal virus identified. Since then, FMDV has become a model system in animal virology and a considerable amount of information on its structure, biology and vaccinology has been obtained. However, the disease that this virus produces (FMD) still constitutes one of the main animal health concerns. In this review, we have attempted to summarise the state of the knowledge in different basic and applied areas of FMDV research, with emphasis on those aspects relevant to the control of the disease.; Le virus de la fièvre aphteuse : un virus connu de longue date, qui demeure une menace. Le virus de la fièvre aphteuse a été le premier virus animal identifié. Depuis lors, il est devenu un système modèle en virologie animale, et une quantité importante d'informations sur sa structure, sa biologie et sa vaccinologie a été obtenue. Cependant la maladie provoquée par ce virus constitue encore une inquiétude majeure en santé animale. Dans cette revue, nous avons tenté de résumer l'état des connaissances dans différents domaines de recherche, à la fois fondamentaux et appliqués, sur le virus de la fièvre aphteuse, en mettant l'accent sur les aspects relatifs au contrôle de la maladie.

Plusieurs etudes ont mis en evidence les proprietes alicamenteuses des isoflavones du soja. Ces proprietes leur conferent un potentiel de prevention vis-a-vis des maladies cardio-vasculaires, de certains cancers et des problemes en lien avec la menopause. Cependant, des influences nefastes au niveau, notamment, du developpement reproducteur et de la fertilite de plusieurs especes animales ont ete etablies. Des differences de biodisponibilite et de metabolisme de ces composes bioactifs ont ete observees entre individus mais egalement entre les differentes isoflavones du soja (12 isoflavones differentes ont ete isolees dans les graines et les produits a base de soja). Par ailleurs, plusieurs facteurs en lien avec le genotype et le milieu de culture influencent la teneur et la composition de ces composes dans la graine. Enfin, les procedes de production affectent egalement la teneur et/ou la composition en isoflavones dans les produits a base de soja.

International audience; Characterization of cork growth and quality in one region of production. Cork growth and quality were characterised in 5 cork oak stands within the production area of the Sado basin (Alcácer do Sal, Portugal) based on a field sampling on 40 trees/stand. Cork thickness was on average 33.8 mm, with 75% of the samples in the commercial classes above 27 mm suitable for production of stoppers. Porosity measured by image analysis was 4.6% on average. Between tree and between stand variability of cork quality was large. The annual average cork growth for a production cycle with 8 complete growth years was 4.1 mm, being highest during the years following cork extraction and decreasing during the cycle. For this region, a production cycle of 9 years is adequate for raw-material industrial requirements. The results show the importance of between tree variability in growth and especially in quality.; La croissance et la qualité du liège ont été caractérisées pour cinq suberaies de la région de production du bassin du fleuve Sado (Alcácer do Sal, Portugal), par un prélèvement d'échantillons sur 40 arbres par peuplement. En moyenne, l'épaisseur du liège était de 33,8 mm, dont 75 % du total appartenant aux classes commerciales au dessus de 27 mm, aptes au bouchonnage, et la porosité, mesurée par analyse d'image, 4,6 %. La qualité du liège montre une grande variabilité entre arbres d'une même suberaie et aussi entre suberaies. L'accroissement annuel moyen du liège pour un cycle de production de 8 ans complets était 4,1 mm. La croissance des années qui suivent le déliégeage est plus grande et diminue pendant le cycle. Pour cette région, le cycle de production de 9 ans est adapté aux débouchés industriels de la matière première. Les résultats montrent l'importance de la variabilité entre arbres de la croissance du liège et surtout de sa qualité.

The length and width of 1297 Fasciola hepatica eggs shed in cattle hosts, 337 in sheep and 199 in nutria, were measured from several parts of France. The data were compared with those obtained from other studies in Spain, France (where rats were also investigated), Germany and the Netherlands. One way analysis of variance and discriminant analysis were used to assess differences between host origins. The distribution of length and width of eggs were analysed using skewness and kurtosis Fisher coefficients. The eggs recovered from sheep, cattle, rodents and lagomorphs were different in size: the eggs found in rodents (length L × width W in μm: 8592) and lagomorphs (L × W in μm: 9100) were smaller than those found in sheep and cattle (L×W in μm: 10,000). These morphological differences in F. hepatica eggs were host-induced in rats (L×W in μm: 9709 in cattle to 8949 in rats) and rabbits (L×W in μm: 9709 in cattle to 8432 in rabbits). These differences in size of eggs might correspond to their being less able to develop into miracidia in less frequent hosts such as rodents and rabbits.

La cytométrie en flux a été utilisée pour estimer la quantité d'ADN nucléaire chez 13 espèces de #Coffea$ (Rubiacea) originaires d'Afrique. Douze espèces diploïdes (#2n$=22) et l'espèce tétraploïde #C. arabica$ (#2n$=44) ont été analysées. Pour 77 génotypes, des populations de noyaux isolés ont été colorées par l'iodure de propidium (IP ; non spécifique des bases). Pour trente neuf génotypes, le 4',6-diamidino-2-phenylindole (DAPI; AT spécifique) a été également utilisé. Les quantités 2C d'ADN nucléaire, estimées avec l'IP, oscillent entre 0,95 et 1,78 pg. Trois groupes correspondant à des quantités croissantes d'ADN ont été mis en évidence. Les trois espèces #C. sessiliflora, C. racemosa$ et #C. pseudozanguebariae$ se classent dans le groupe des plus petites valeurs (groupe 1 : 0,90 à 1,30 pg). Les trois espèces #C. eugenioides, C. stenophylla$ et #C.$ sp. F. se rangent uniquement dans le groupe des valeurs intermédiaires (groupe 2 : 1,31 à 1,60 pg). Les autres espèces se répartissent entre le groupe 2 et le groupe des plus hautes valeurs (groupe 3 : 1,61 à 1,80 pg). Les valeurs déterminées pour les espèces de #Coffea$, sont comparées aux niveaux intra- et inter-spécifique à celles d'autres angiospermes. Les différences observées sont discutées en fonction de l'origine éco-géographique des espèces, leurs caractéristiques phénologiques et la fertilité de leurs hybrides F1 interspécifiques. (Résumé d'auteur)

Summary. -Description and discussion of a new pattern of coloured dermal scales in a weevil species from Réunion Island appearing suddenly in a species known as stable for at least one century., Résumé. -Description de la variabilité des écailles dermiques colorées apparue récemment dans une population de Charançons dans l'Ile de la Réunion considérée jusqu'à présent comme stable., Richard Raymond, Paulian Renaud. Note sur l'apparition brusque d'une variation importante de la squamulation de Cratopus humeralis Boheman (Coleoptera, Curculionidae). In: Bulletin de la Société entomologique de France, volume 100 (3), août 1995. pp. 303-306.

BACKGROUND: Although Chinese-origin Rhesus macaques (Ch RhMs) infected with simian immunodeficiency virus (SIV) have been used for many years to evaluate the efficacy of AIDS vaccines and therapeutics, the bio-clinical variability of such a nonhuman primate AIDS model was so far not established. METHODOLOGY/PRINCIPAL FINDINGS: By randomizing 150 (78 male and 72 female) Ch RhMs with diverse MHC class I alleles into 3 groups (50 animals per group) challenged with intrarectal (i.r.) SIVmac239, intravenous (i.v.) SIVmac239, or i.v. SIVmac251, we evaluated variability in bio-clinical endpoints for 118 weeks. All SIV-challenged Ch RhMs became seropositive for SIV during 1-2 weeks. Plasma viral load (VL) peaked at weeks 1-2 and then declined to set-point levels as from week 5. The set-point VL was 30 fold higher in SIVmac239 (i.r. or i.v.)-infected than in SIVmac251 (i.v.)-infected animals. This difference in plasma VL increased overtime (>100 fold as from week 68). The rates of progression to AIDS or death were more rapid in SIVmac239 (i.r. or i.v.)-infected than in SIVmac251 (i.v.)-infected animals. No significant difference in bio-clinical endpoints was observed in animals challenged with i.r. or i.v. SIVmac239. The variability (standard deviation) in peak/set-point VL was nearly one-half lower in animals infected with SIVmac239 (i.r. or i.v.) than in those infected with SIVmac251 (i.v.), allowing that the same treatment-related difference can be detected with one-half fewer animals using SIVmac239 than using SIVmac251. CONCLUSION/SIGNIFICANCE: These results provide solid estimates of variability in bio-clinical endpoints needed when designing studies using the Ch RhM SIV model and contribute to the improving quality and standardization of preclinical studies.

The Caninae are especially abundant in the Plio-Pleistocene record of Western Europe where several genera, species and subspecies have been recognized, with some still under discussion about taxonomical attribution. They have important ecological roles among carnivoran guilds throughout the Quaternary, and some are high-level competitors. Their appearance and dispersal can be considered as major bioevents during different phases of the Quaternary. They therefore are relevant biochronological markers which can be correlated with main European faunal turnovers, from the ‘wolf-event’ at the end of the Pliocene, followed by high taxonomic diversity in Early to Middle Pleistocene and specific lineage with high size variation during the Middle and Late Pleistocene. As for many other mammals with very wide distribution, Canids demonstrate a relative high morphological and body-size (clinal) variability which in one sense are often underestimates and lead to creation of taxa from a geographical base, especially in southwestern Europe, characterized by high regional peculiarities (e.g. peninsular condition). This paper proposes a preliminary analysis, mostly based on teeth morphometry, of the taxonomy of wolf- and coyote/jackal-sized canids from distinct examples in southwestern Europe: small canids of Early Pleistocene age, discussion of genus Cuon and analysis of the etruscus-mosbachensis-lupus lineage. The contribution of Canids as biochronological taxa are discussed.

Variability of diapause in populations of Heliothis armigera Hb. (Lep., Noctuidae) The incidence of diapause in some populations of Heliothis armigera collected between latitudes 25°S to 44°N was examined. Diapause occurred in all populations reared in short photoperiod situation (LD < 12 : 12). The percentage of pupae in diapause was variable. The effect of family and the dates of collecting samples from adjacent marroccan populations in diapause and its intensity was measured. Significant heterogeneity in diapause induction and development was found between and in populations and families. However, there is little evidence of any geographical pattern to this variation. Resume Les potentialites diapausantes de H. armigera, etudiees sur differentes populations geographiquement proches et eloignees se caracterisent par une variabilite inter et intrapopulation importante. Cette variabilite difficile a associer a un facteur ecologique precis releve peut ě tre des particularites ecoethologiques de l'insecte. Elle serait davantage en rapport avec l' heterogeneite naturelle de l'espece qu'en liaison avec une structuration genetique resultant d'un isolement reproductif. Zusammenfassung Zur Variabilitat der Diapause bei Populationen von Heliothis armigera Hb. (Lep., Noctuidae) Das Auftreten der Diapause wurde bei einigen Populationen von H. armigera zwischen den Breitengraden 25′S und 44′N untersucht. Die Diapause trat bei allen Populationen auf, die in kurzen Photoperioden (LD < 12 h) aufwuchsen. Der Prozentsatz der diapausierenden Puppen war variabel. Der Familieneffekt und der Einflus der Sammeldaten von benachbarten marokkanischen Populationen auf die Diapause und ihre Intensitat wurden festgestellt. Es wurde eine signifikante Heterogenitat in der Diapause-Induktion und -Entwicklung zwischen und in den Populationen und Familien gefunden. Jedoch gibt es wenig Hinweise auf das Bestehen geographischer Muster bei dieser Variation.

Veterinary medicine faces the unique challenge of having to treat many types of domestic animal species, including mammals, birds, and fishes. Moreover, these species have evolved into genetically unique breeds having certain distinguishable characteristics developed by artificial selection. The main challenge for veterinarians is not to select a drug but to determine, for the selected agent, a rational dosing regimen because the dosage regimen for a drug in a given species may depend on its anatomy, biochemistry, physiology, and behaviour as well as on the nature and causes of the condition requiring treatment. Both between- and within-species differences in drug response can be explained either by variations in drug pharmacokinetics (PK) or drug pharmacodynamics (PD), the magnitude of which varies from drug to drug. This chapter highlights selected aspects of species differences in PK and PD and considers underlying physiological and patho-physiological mechanisms in the main domestic species. Particular attention was paid to aspects of animal behaviour (food behaviour, social behavior, etc.) as a determinant of interspecies differences in PK or/and PD. Modalities of drug administration are many and result not only from anatomical, physiological and/or behavioural differences across species but also from management options. The latter is the case for collective/group treatment of food-producing animals, frequently dosed by the oral route at a herd or flock level. After drug administration, the main causes of observed inter-species differences arise from species differences in the handling of drugs (absorption, distribution, metabolism, and elimination). Such differences are most common and of greatest magnitude when functions which are phylogenetically divergent between species, such as digestive functions (ruminant vs. non-ruminant, carnivore vs. herbivore, etc.), are involved in drug absorption. Interspecies differences also exist in drug action but these are generally more limited, except when a particular targeted function has evolved, as is the case for reproductive physiology (mammals vs. birds vs. fishes; annual vs. seasonal reproductive cycle in mammals; etc.). In contrast, for antimicrobial and antiparasitic drugs, interspecies differences are more limited and rather reflect those of the pathogens than of the host. Interspecies difference in drug metabolism is a major factor accounting for species differences in PK and also in PD (production or not of active metabolites). Recent and future advances in molecular biology and pharmacogenetics will enable a more comprehensive view of interspecies differences and also between breeds with existing polymorphism. Finally, the main message of this review is that differences between species are not only numerous but also often unpredictable so that no generalisations are possible, even though for several drugs allometric approaches do allow some valuable interspecies extrapolations. Instead, each drug must be investigated on a species-by-species basis to guarantee its effective and safe use, thus ensuring the well-being of animals and safeguarding of the environment and human consumption of animal products.

Thirty-six single-ascospore isolates of Leptosphaeria maculans were obtained from eight stubbles of diseased Brassica napus plants collected from two locations in France. The isolates were assessed for (i) their sirodesmin PL and phomenoic acid production in vitro; (ii) their esterase profiles following native polyacrylamide gel electrophoresis; and (iii) their protein patterns obtained by isoelectric focusing. Two groups of isolates could be discriminated according to their toxin production, i.e. isolates producing both sirodesmin PL and phomenoic acid, termed Tox+, and those producing neither of these compounds, termed Tox0. The same clear-cut separation between Tox+ and Tox0 isolates was observed when analysing esterase or soluble protein profiles. In the latter case, the mean similarity index between isolates was 46% when belonging to different groups, and 88–92% when belonging to the same group. Esterase patterns were highly polymorphic within the Tox0 group, and factorial correspondence analysis of soluble protein profiles showed that one individual clearly departed from the main cluster. Within the Tox+ group all the isolates displayed the same five esterase bands. Within this group a high degree of homology between protein profiles was also observed. Nevertheless, three major bands could be used to further characterize Tox+ isolates and discriminate them into subgroups. Both Tox0 and Tox+ isolates were present in each of the collection areas, and even on the same stubble.

The nuclear rDNA units of species belonging to the genus Beta were characterized using heterologous probes of flax (entire unit and 25S) and sunflower (6.1-kb Eco fragment containing the 18S, the entire intergenic spacer (IGS) and a small piece of the 25S). The physical maps of one species from each section of the genus was constructed by localization of the EcoRI, BamHI, HindIII, KpnI and SacI restriction sites. For each species a single individual was used to obtain total DNA. The major unit length is 11 kb, but variant length units at 10.4, 10.7 and 11.3 kb were found as minor forms. However, some individuals carried the 10.4-kb or the 10.7-kb variant length unit as the major form. For the variant length units of one species the restriction sites were conserved, so that the variation in length occurred in the IGS. The EcoRI fragment corresponding to the intergenic spacer appeared to be the best indicator of variation. The variable sequence in the IGS sometimes generated new restriction sites for the Corollinae and mainly, did so, for the Vulgares relative to the Procumbentes. The variable sites were able, to differentiate the three sections and species within the sections. Corollinae species belong to two different groups according to the absence or the presence of the BamHI (B4) site. The Vulgares species contain several unit types. We proposed that all the unit types derived from a unique unit, V-11-2.3, by unequal crossing-overs or conversion. We also supposed a homogenization mechanism because we found individuals homogeneous for every unit type. Among the cultivated beets, all the root beets contain only one rDNA unit type, V-11-2.9. Thus, we supposed that the common unit type of cultivated beets either brings a physiological advantage or is strictly linked to a favorable allele. It is likely that the rDNA unit of B. maritima were eliminated from sugar beet by the breeding process since they were not recovered. Whatever the process, we deduced that all the cultivated forms of beets likely originated in a unique plant ascendant.A phylogenic tree of the genus is proposed, based on the nuclear rDNA maps, and subsequently discussed relative to the systematic tree and other molecular phylogenies.

Le potentiel hydrique de base, le potentiel hydrique minimal et la conductance stomatique maximale ont ete mesures sur 2 arbres pionniers (Trema micrantha, Goupia glabra) et un arbre forestier (Eperua grandiflora) au cours des 2 periodes seches de 1987, a Cayenne, Guyane francaise. Trema est localement spontane tandis que les goupis proviennent de sauvageons transplantes et les wapas de semis. Les plants des 3 especes ont environ 2 ans et demi, puis 3 ans au moment des mesures. Les resultats montrent des differences de comportement importantes entre les 3 especes. Trema maintient un potentiel hydrique et une transpiration eleves (mais perd une partie de sa surface foliaire) tandis que le goupi accuse une forte baisse de potentiel et doit reguler sa transpiration

International audience; This review provides an overview of recent progress in the exploration of genomic, transcriptomic, and proteomic data in Listeria spp. to understand genome evolution and diversity, as well as physiological aspects of metabolism utilized by the bacteria when growing in diverse and varied environments.

The sanitary status of pome fruit trees was evaluated in central and northern Greece during a survey in the autumn of 2004 and spring of 2005. Twenty-six leaf samples were collected from five symptomless and 21 symptomatic quince trees showing fruit deformation (FD) symptoms and diffuse chlorotic leaf spots. All samples were tested for the presence of Apple chlorotic leaf spot virus (ACLSV), a member of the Trichovirus genus, initially by ELISA and then by a specific reverse transcription (RT)-PCR assay reported previously (1). ACLSV has a broad host range that includes most, if not all, Prunoidae (peach, apricot, plum, and cherry) and Maloidae (apple, pear, and quince) fruit tree species. Although it has been tentatively linked with fruit, leaf, bark, and growth retardation symptoms in quince (2,3), its geographic distribution and association with specific symptoms is still poorly determined. ACLSV was initially detected by serology in two plants, one symptomless and one showing FD symptoms. ACLSV presence in these two samples and in an additional symptomless plant was confirmed by the ACLSV-specific RT-PCR assay. Sequencing of the RT-PCR amplicon from the symptomatic isolate (EMBL Accession No. AM292923), which was positive in both assays, confirmed the identification of ACLSV. The obtained sequence shows 93% nucleotide identity with an apple isolate of ACLSV (EMBL Accession No. AY677103). To our knowledge, these findings represent the first report of the presence of ACLSV in quince in Greece. They further indicate that at least for some host-cultivar/virus isolate combinations, ACLSV may be asymptomatic in quince and that the symptoms observed in the plants sampled are unrelated to ACLSV infection. References: (1) T. Candresse et al. Acta Hortic. 386:136, 1995. (2) J. C. Desvignes. Page 202 in: Virus Diseases of Fruit Trees. CTIFL Publishing, 1999. (3) S. Paunovic and M. Rankovic. Jugosl. Vocarstvo 31:231, 1997.

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; A panel of 19 monoclonal antibodies (mAbs) was used to study the immunological variability of Lettuce mosaic virus (LMV), a member of the genus Potyvirus, and to perform a first epitope characterization of this virus. Based on their specificity of recognition against a panel of 15 LMV isolates, the mAbs could be clustered in seven reactivity groups. Surface plasmon resonance analysis indicated the presence, on the LMV particles, of at least five independent recognition/ binding regions, correlating with the seven mAbs reactivity groups. The results demonstrate that LMV shows significant serological variability and shed light on the LMV epitope structure. The various mAbs should prove a new and efficient tool for LIVIV diagnostic and field epidemiology studies.

Besides being a metabolic fuel, carbohydrates play important roles in plant growth and development, in stress responses, and as signal molecules. We exploited natural variation in Arabidopsis (Arabidopsis thaliana) to decipher the genetic architecture determining carbohydrate content. A quantitative trait locus (QTL) approach in the Bay-0 × Shahdara progeny grown in two contrasting nitrogen environments led to the identification of 39 QTLs for starch, glucose, fructose, and sucrose contents representing at least 14 distinct polymorphic loci. A major QTL for fructose content (FR3.4) and a QTL for starch content (ST3.4) were confirmed in heterogeneous inbred families. Several genes associated with carbon (C) metabolism colocalize with the identified QTL. QTLs for senescence-related traits, and for flowering time, water status, and nitrogen-related traits, previously detected with the same genetic material, colocalize with C-related QTLs. These colocalizations reflect the complex interactions of C metabolism with other physiological processes. QTL fine-mapping and cloning could thus lead soon to the identification of genes potentially involved in the control of different connected physiological processes.

Serological reactivity to Plum pox virus (PPV) antisera has been described in several Prunus sources of Asian origin that are free of PPV infection. Using polyvalent or specific PCR assays, the presence of three closely related agents in two of these sources, Prunus mume cv. Bungo and P. persica cv. Ku Chu'a Hung, was demonstrated. Similarities in genome organization and sequence comparisons indicate that these agents should be regarded as members of the genus Foveavirus, their only singular trait being a very large (>800 nt) 3' non-coding region (NCR), as compared to the ca. 130-180 nt 3' NCR observed in other Foveaviruses. The three agents are very divergent from known Foveaviruses but are also significantly removed one from the others, with overall nucleotide sequence identity levels in the sequenced region of ca. 74-76% and of only 60.8-67.5% in their complete CP gene (61.9-71.3% amino acid sequence identity). Given the species discrimination criteria in the family Flexiviridae, these three agents should be regarded as three related yet distinct new viruses belonging to the Foveavirus genus, for which the names Asian prunus virus 1, 2 and 3 are proposed. Evidence is provided for the presence of variants of these new viruses in other Prunus germplasm of Asian origin.

Thlaspi caerulescens is known to hyperaccumulate high quantities of Cd with Car concentrations up to 3000 mg kg(-1) in some populations from south of France. However, within these populations, the Car concentrations can vary widely from plant to plant in a way that appears to be not entirely due to variations in soil Cd. The aim of this work was to investigate the variability in the Cd uptake ability of individual plants within a population and among seedlings grown from seeds from a single plant. Ten populations of T. caerulescens plants were selected from four locations (V. Viviez; SF: Saint Felix-de-Pallieres; LB: Le Bleymard; CMA: Col do Mas de I'Air) depending of the extent and soil homogeneity of the site. One population from CMA consisted of the progeny of a single maternal plant. Hundred plants of each population were grown for three months in the same homogeneous and lightly Cd-polluted soil (about 20 mg total Cd kg(-1) dry soil). Cadmium uptake behavior of the plants was monitored by labeling the soil with Cd-109. To allow partial plant destruction, radioanalysis was performed on the largest leaf of each plant as an indicator of the total Car concentration in plant shoots. Results showed significant differences in biomass production and Cd uptake by T. caerulescens between sites and between populations within sites. We observed a wide intra-population variation in biomass, Cd concentration and total Cd uptake. For these properties, 1 to 5 percents of the plants in each population varied by more than a factor of two from the mean values. The mean Cd uptake by the single-plant population from CMA was more than 40% higher than for the population at large. T. caerulescens would respond to traditional selection methods, which would significantly improve the phytoextraction of Cd.

The purpose of this study was to characterize some quality descriptors of wild Eurasian perch, Perca fluviatilis, taking into account spatial and temporal variability and to situate quality in reared perch in comparison with wild perch variability. Two different natural systems (Leman Lake and the Rhine River) were selected to characterize perch quality variability during an entire biological cycle. Farmed perch quality was studied in relation to the rearing system (extensive, semi-extensive and intensive systems). Using the morphometric, technological and color descriptors, it was shown by Principal Components Analyses (PCA) that in the Rhine River, fish had compact body and caudal fin, large mouth and head and possessed a more reddish caudal fin, in comparison to fish from Leman Lake that are brighter. Seasonal variations were different according to the natural system. In the lacustrian system, fish presented low seasonal variations contrary to the Rhine River system for morphometric and color variables. The technological attributes showed the highest degree of seasonal variation, e.g. fillet yield was high in July. These technological variables were found as being the main discrimination way between fish from the different rearing systems. The intensive rearing system produced perch with higher hepatosomatic index (IH) and perivisceral fat index (IPF) compared with the extensive and semi-extensive rearing systems. Moreover, the more intensive rearing conditions were, the more fat deposits increased. It was also found that reared perch possessed wild-like quality characteristics, except for some technological variables (viscerosomatic index: IV and fillet yield: YF). Furthermore, perch from the semi-extensive system had the most similar quality attributes with fish from the Rhine River. Thus, morphology and color (i.e. color of caudal fin) appeared to be pertinent quality descriptors for wild fish, whereas technological attributes were more adequate for the characterization of reared fish quality. This study also suggested some hypothesis about the direct or indirect relationships between abiotic factors, such as chemical water characteristics, transparency, temperature and quality attributes.

Although it has been recognized as a key parameter of wood quality and a good source of information on growth, annual wood density has been little studied within diffuse-porous trees such as beech ( Fagus sylvatica Liebl.). In this paper we examine the variability encountered in beech ring density series and analyze the influences of ring age, ring width, climate and between-tree variability on density. Thirty ring sequences were sampled from 55-year- old dominant beech trees growing within the same stand; ring density and width were measured using radiography. Ring density proved to be less variable through time than ring width. The relationship between these two variables was less than observed in ring-porous trees and it showed great variation between trees. The sensitivity of ring width and density to climate was also different; width was strongly linked to soil water deficit whereas density was correlated to temperature and August rainfall. Unlike ring width, wood density showed sensitivity towards climatic characteristics of the late growing season. A large part of annual density variability remains unexplained, even using advanced modelled water balance variables. We hypothesize that a significant part of the tree ring is under internal control. We also demonstrated great inter-tree variability (the tree effect) in ring density, which has an influence on density but not on trees’ response to climate.

Dicorynia guianensis Amsh. is very widespread in the forests of French Guiana and moreover is the leading species harvested in this area, but its main defect remains the great variability of wood durability, especially with respect to fungal decay. The aim of this work was to study this inter- and intra-tree variability in order to identify the parameters responsible for this variation (growth area, height and radial position) within the tree. The resistance decrease from the outer heartwood to the pith. Measurement of colour variation using the CIELAB (L*, a*, b*, C*, h*) system was performed at the intra-tree level to highlight the longitudinal and radial gradients of variation. Dicorynia guianensis becomes less red and dark from the outer to the inner heartwood and from the base to the top. Lastly, variations of colour and durability were correlated: the wood is less resistant the redder and darker it is., Dicorynia Guianensis Amsh. est une essence très répandue dans les forêts de Guyane française. C'est l'une des essences les plus exploitées cependant elle souffre d'un défaut majeur : une grande variabilité de sa durabilité naturelle à l'égard des champignons lignivores (Ascomycètes, Basidiomycètes). À travers l'étude de la variabilité inter-arbre et intra-arbre nous avons discuté de l'influence de paramètres tels : la localité, la taille de l'arbre, la hauteur et la position radiale sur la résistance naturelle. Dans une deuxième partie nous avons étudié l'influence de ces mêmes paramètres sur la mesure de la couleur (système CIELAB) du bois à l'échelle intra-arbre. Nous avons ainsi constaté que le paramètre « position radiale » était de loin le plus important à l'origine de la variabilité : Dicorynia guianensis est plus résistant du duramen interne vers le duramen externe ; moins rouge et moins sombre du duramen externe vers le duramen interne. Enfin, nous avons constaté que les variations de couleur et de durabilité chez Dicorynia guianensis étaient corrélées : le bois est d'autant plus résistant qu'il est moins rouge et plus clair sombre.

International audience; Milk fat has a large effect on nutritional, technological and sensorial properties of milk products. The milk fat content and composition are modulated by genetics and nutritional factors and imply a large number of enzymes. The regulation of their gene expression in the mammary gland still needs to be clarified. An association between the extensive polymorphism at the $\alpha_{s1}$-casein ($\alpha_{s1}$-Cas) locus and both the lipid content and the characteristics of this fraction in caprine milk has been demonstrated. In order to decipher the mechanism responsible for this impact, a quantification of the transcripts of four lipogenic key enzymes (acetyl-CoA carboxylase, fatty acid synthase, lipoprotein lipase and stearoyl-CoA desaturase)was performed using real-time RT-PCR, suggesting an absence of association between the $\alpha_{s1}$-Cas genotype and expression variability of the studied genes. This approach has been completed by a more global analysis using a first generation of ruminant macroarray gathering 400 gene probes. The comparison of the expression profiles of lactating goat $\alpha_{s1}$-Cas A/A (strong allele) and F/F (defective allele) mammary gland allowed to confirm the expected variability in the expression of known genes (such as those encoding the $\alpha_{s1}$-casein) in ruminant mammary tissues as well as to identify up- and down-regulated genes. A second generation of ruminant cDNA macroarray extended to a few thousands of genes is currently in progress and will be applied to study different factors such as the nutritional regulation of gene expression in themammary gland.

International audience; The RNA 2 of the nepovirus Arabis mosaic virus (ArMV) encodes a polyprotein from which protein 2A is released by proteolytic cleavage at the N-terminus. The 2A gene of 19 ArMV isolates from different geographical origin and 9 distinct natural hosts was amplified by RT/PCR and subsequently cloned and sequenced. These 19 isolates and those from databanks were classified into four groups based on the size of the protein 2A which ranged from 233 to 280 amino acids, and sequence identities. Sequence variability was mainly located in the N-terminus of the proteins, whereas the core region and the C-terminus were conserved.

Summary • Variability in the fungal endophytes of 83 natural populations of Lolium perenne (perennial ryegrass) from Europe was assessed. • One plant per population was used for endophyte isolation and mycotoxin analysis. Variability in three isozymes, colony morphology and growth rate on potato dextrose agar (PDA), and synthesis of ergovaline, lolitrem B and peramine was recorded. • Three species were found among 94 strains isolated: Neotyphodium lolii, Neotyphodium sp. (LpTG-2) and Gliocladium-like. The most frequent species was N. lolii, which showed high variability. In 12 populations, a single plant harboured two different endophytes. One-third of the isolates of N. lolii did not produce ergovaline whereas a few isolates did not produce lolitrem B. Ergovaline and lolitrem B-deficient strains, but not the few peramine-deficient isolates, had characteristic morphologies on PDA. No isolate was deficient for both ergovaline and lolitrem B synthesis. • Selection of ergovaline and lolitrem-deficient strains based only on the morphology of the isolates in culture may be possible.

The relationship between specific growth rate and initial body weight in fish was analysed by multivariate analysis using data sets from growth studies on rainbow trout (initial weight between 10 and 30 g, n =546) and Atlantic salmon (initial weight between 10 and 20 g, n =355). We demonstrate that individuals can be pooled into different classes according to their growth characteristics. Classes with similar initial mean weight can have very different mean specific growth rate. Indeed, we found the mean specific growth rate ratio between classes with similar initial mean weight to be between 1.5 and 5.8 in rainbow trout and between 1.2 and 1.9 in Atlantic salmon. We conclude that the constitution of replicates with homogeneous initial weight is not assurance of homogeneous specific growth rate among replicates. The consequences of such variability in growth on experimental designs and power of analysis-of-variance models are discussed.

International audience; Classical selection for increasing prolificacy in sheep leads to a concomitant increase in its variability, even though the objective of the breeder is to maximise the frequency of an intermediate litter size rather than the frequency of high litter sizes. For instance, in the Lacaune sheep breed raised in semi-intensive conditions, ewes lambing twins represent the economic optimum. Data for this breed, obtained from the national recording scheme, were analysed. Variance components were estimated in an infinitesimal model involving genes controlling the mean level as well as its environmental variability. Large heritability was found for the mean prolificacy, but a high potential for increasing the percentage of twins at lambing while reducing the environmental variability of prolificacy is also suspected. Quantification of the response to such a canalising selection was achieved.

International audience; Sequence variability in the PCR amplified cDNAs from two citrus apscaviroid isolates CVd-Ia and CVd-IIId from Spain, was analysed. CVd-IIId sequence was shown to be identical to previously described CVd-III sequences and no important variability was encountered within the viroid population. Conversely, CVd-Ia displayed population heterogeneity as shown by SSCP analysis, Sal I restriction site polymorphism and sequences of 27 CVd-Ia cloned DNAs. The CVd-Ia genomic heterogeneity is characterised by two major subpopulations with the most divergent sequences, and by the presence of individual variants, making a sequence continuum between the two major groups. Most sequence variations are clustered in the left part of the viroid molecule.

Physicochemical surface properties, related to electrostatic, van der Waals and Lewis acid-base interactions, of five Listeria monocytogenes strains isolated from pork-processing environments were determined after two subcultures at 37 degrees C and a final culture at three temperatures: 37, 10 and 4 degrees C. Three strains (Lm1, Lm114 and Lm191) were genetically related while two were unrelated (Lm25 and Lm74) according to ApaI-macrorestriction and pulsed-field gel electrophoresis (PFGE) typing. Listeria monocytogenes cell surfaces were generally negatively charged regardless of pH and tended to be hydrophilic due to a basic character. However, variable physicochemical surface properties of the five Listeria monocytogenes isolates were observed after growth at 37 degrees C. After growth at 10 degrees C, the three genetically related isolates exhibited similar surface properties and were slightly more hydrophilic and basic than the others. After growth at 4 degrees C, the five isolates displayed the same weak affinity for all kinds of solvents and low electrophoretic mobility values. A sharp decrease of temperature and subsequent growth of various Listeria monocytogenes strains resulted in loss of the physicochemical surface property variability, which may suggest the role of common chill adaptation mechanisms affecting surface properties.

Le matériel expérimental est constitué de 82 chênes sessiles (ou rouvres) issus de 48 parcelles de futaie ou taillis-sousfutaie réparties dans 5 zones géographiques françaises (Convention ONF-INRA 1992-1996 « Sylviculture et Qualité du bois de chêne (chêne rouvre) »). Pour chacun des arbres, deux extractions ont été réalisées sur les 15 premiers cernes du duramen de deux rayons opposés situés à 1,30 m de la base de l’arbre. La densité optique à 280 nm (qui pour le type d’extraction réalisé est très corrélée à la teneur en tannins), les méthyl-octalactones et des phénols volatils (dont l’eugénol) ont été dosés. Les effets « arbre dans la parcelle », « parcelle dans type peuplement ´ région », « type de peuplement ´ région », « région » et « type de peuplement » ont été testés par analyse de variance. Pour la majorité des composés, l’effet arbre est très significatif. Le type de peuplement est très influent sur la teneur en tannins, les arbres de futaie en possèdent moins que les arbres de taillis-sous-futaie. Les régions se différencient uniquement pour les teneurs en eugénol. Pour les méthyl-octalactones, on observe un peu plus de la forme trans pour les arbres de futaie et pas d’effet peuplement ou région pour la forme cis., The experimental material consists of 82 sessile oaks sampled from 48 plots characterized by two types of silvicultural management: high forest and coppice with standard. These plots are located in five french regions: Allier, Loir-et-Cher, Orne-Sarthe, Lorraine and Alsace (ONF-INRA convention 1992-1996 “Sylviculture et Qualité du bois de chêne (chêne rouvre)”). For each tree, two extractions were made from the first 15 rings of the heart-wood of two opposite radii which were situated at 1.30 m from the bottom of the tree. Optic density at 280 nm (which is well correlated with tannin content for this type of extraction) and the concentrations of methyl-octalactones and volatile phenols (among which eugenol) were measured. Different effects were tested by variance analysis: “tree within plot”, “plot within type of management ´ region”, “type of management ´ region”, “region” and “type of management”. For the majority of compounds, tree effect is very significant. Significances for plot effect and for interaction of region with type of management are generally poor. The effect of “type of management” is very significant for tannins, trees of high forest having lower concentrations than trees of coppice with standard. Regions only differ by eugenol content. For methyl-octalactones, there is a little more of the trans racemic form for high forest and no type of management or region effect for the cis racemic form.

International audience; Initial searches found little evidence of genotypic or phenotypic variance in the parasitic bee mite Varroa jacobsoni, despite numerous reports of significant variation in the mite's reproductive behaviour on its adopted host Apis mellifera. However, in a recent search that employed DNA sequencing techniques and large numbers of V. jacobsoni collected from the mites' native host A. cerana throughout Asia, a remarkable amount of genetic variation was observed. Subsequent analysis of this variation, coupled with follow-up morphological and ecology-based studies, showed that V. jacobsoni was a species complex. Other work carried out as part of that study also showed that only two out of 18 genetically different mites within the complex have switched host to A. mellifera and become a pest of this bee worldwide. These two mites are not V. jacobsoni as has been assumed, but they belong to a group of mites that naturally infest specific populations of A. cerana on mainland Asia. These mites will soon be renamed as a new species. This and other reports of variation in V. jacobsoni are reviewed and discussed.; Diversité chez l'acarien Varroa jacobsoni Oud., parasite des abeilles. Les études initiales sur la morphologie ont montré peu de différences, à l'exception de la taille, entre les femelles de Varroa jacobsoni. Puisque les acariens parasitant la petite abeille Apis cerana sont significativement plus petits que ceux qui parasitent l'abeille A. mellifera plus grosse, on a tout d'abord supposé que les différences de taille dépendaient de l'espèce hôte. On connaissait depuis longtemps l'existence de différences dans la reproduction de l'acarien sur son nouvel hôte, A. mellifera. Les femelles de l'acarien se reproduisent sans difficultés sur le couvain de mâles et le couvain d'ouvrières d'A. mellifera en Europe, au Moyen-Orient, en Asie et dans certaines régions d'Amérique. La plupart des colonies ne survivent pas à l'attaque parasitaire sans méthode de lutte efficace. Dans quelques régions tropicales et subtropicales d'Amérique, les acariens se reproduisent nettement moins qu'en Europe ou au Moyen-Orient. La mortalité des acariens est plus élevée qu'en Angleterre, si bien qu'A. mellifera se montre tolérante à V. jacobsoni dans la zone tropicale de l'Amérique du Sud. Pourtant, lors de recherche en Indonésie, on a mis en évidence que les acariens de Java, qui avaient été décrits en 1904 sous le nom de V. jacobsoni, ne pouvaient pas du tout se reproduire sur A. mellifera. D'autres facteurs, comme des différences dans le génotype des acariens, pourraient influer la capacité à se reproduire. Au début, la recherche de différences génétiques s'est limitée presqu'uniquement aux populations présentes sur le nouvel hôte, A. mellifera, et on a trouvé peu de diversité. Les études plus récentes utilisant les techniques de séquençage de l'ADN ont porté sur un beaucoup plus grand nombre d'échantillons d'acariens de l'hôte originel, A. cerana, provenant de toute l'Asie. Au total 18 types différents d'acariens (haplotypes) ont été décelés. Le nom du pays ou de l'île d'où il était issu a été attribué à chaque haplotype. Les analyses assistées par ordinateur ont classé les 18 haplotypes en deux groupes principaux, plus trois haplotypes distincts venant des Philippines. L'un des deux groupes principaux comprend les acariens de la région malaise-indonésienne (Malaisie, Sumatra, Bornéo, Java, Bali, Lombot, Sumbawa, Flores et Ambon). Dans l'autre groupe principal on trouve les acariens du continent asiatique (Japon, Corée, Chine, Vietnam, Népal et Sri Lanka). La distance génétique moyenne des haplotypes au sein de chaque groupe principal est inférieure à 2 % . Cette valeur est si petite qu'il s'agit là bien de variations au niveau de la population. La distance génétique moyenne entre les deux groupes principaux est de 6,2 % ; cette différence est suffisamment grande pour indiquer une séparation au niveau des espèces. D'autres recherches non génétiques ont montré que les acariens du continent sont nettement plus gros et moins ronds que ceux du groupe Malaisie-Indonésie (Fig. 1). On a trouvé en outre que l'haplotype de Java était génétiquement isolé de l'haplotype de Corée. Outre les différences génétiques, les différences phénotypiques et les barrières de reproduction indiquent qu'il s'agit de deux espèces différentes correspondant aux deux groupes principaux. Dans la nouvelle classification, V. jacobsoni est redéfini comme étant le type malais-indonésien, alors que le type du continent asiatique reçoit un nouveau nom (à paraître dans Experimental and Applied Acarology). Une étude approfondie de la variabilité génétique des acariens sur A. mellifera a été menée dans 32 pays. Le résultat est que seuls deux types génétiques différents sont devenus des parasites d'A. mellifera dans le monde entier. Ils sont tous deux également des parasites naturels de populations spécifiques d'A. cerana. L'haplotype de Corée est le plus répandu. Il a été découvert en Afrique, en Europe, en Asie, au Moyen-Orient et en Amérique. L'haplotype du Japon et de Thaïlande est plus rare. Il n'a été trouvé qu'au Japon, en Thaïlande et sur le continent américain. Ces deux types d'acariens appartiennent au groupe continental et recevront le nouveau nom. Les conséquences de ces résultats pour la recherche future et pour les méthodes de lutte alternative sont discutées.

Marked-assisted genetic improvement of agricultural species exploits statistical dependencies in the joint distribution of marker genotypes and quantitative traits. An issue is how molecular (e.g., dense marker maps) and phenotypic information (e.g., some measure of yield in plants) is to be used for predicting the genetic value of candidates for selection. Multiple regression, selection index techniques, best linear unbiased prediction, and ridge regression of phenotypes on marker genotypes have been suggested, as well as more elaborate methods. Here, phenotype-marker associations are modeled hierarchically via multilevel models including chromosomal effects, a spatial covariance of marked effects within chromosomes, background genetic variability, and family heterogeneity. Lorenz curves and Gini coefficients are suggested for assessing the inequality of the contribution of different marked effects to genetic variability. Classical and Bayesian methods are presented. The Bayesian approach includes a Markov chain Monte Carlo implementation. The generality and flexibility of the Bayesian method is illustrated when a Lorenz curve is to be inferred.

The present study is part of a project which aimed to examine the influence of intramuscular fat (IMF) content on the sensory attributes and consumer acceptability of pork. Two experiments were conducted to evaluate the influence of IMF level on the composition of the lipid fraction and on the sensory qualities of muscle longissimus lumborum (LL). Each of these experiments used 32 castrated male pigs selected after slaughter either from 125 Duroc×Landrace (Experiment 1) or 102 Tia Meslan×Landrace (Experiment 2) crossbred animals, and showing large variability in LL IMF content: from1.5 to3.5% in Experiment 1 and from 1.25 to 3.25% in Experiment 2. Results from lipid analyses indicate that in both experiments, an increase in IMF content is almost entirely reflected by an increase in the triglycerides content of the muscle. In Experiment 2, higher IMF content was associated with higher free fatty acids. Marbling score was significantly affected by IMF level in Experiment 1 but not in Experiment 2. In Experiment 1, a trend towards a favourable effect of high IMF levels on flavour (p=0.09) and tenderness (p=0.055) was observed. In experiment 2, increased IMF level was associated with significantly higher juiciness and flavour scores. The results from the present study indicate that the variability in IMF level of LL muscle was almost entirely due to the variability in triglyceride contents. Favourable effects of increased IMF levels on the sensory attributes of pork were demonstrated in both experiments using different types of animals, but the nature and the magnitude of these effects depended on the experiment considered.

The present study is part of a project which aimed to examine the influence of intramuscular fat (IMF) content on sensory attributes and consumer acceptability of pork. Two experiments were conducted to evaluate consumer acceptability of pork chops with varying IMF level in muscle Longissimus lumborum (LL). Each experiment used 32 castrated male pigs selected after slaughter either from 125 Duroc × Landrace (Experiment 1) or 102 Tia Meslan × Landrace (Experiment 2) crossbred animals, and showing large variability in LL IMF content: from1.5 to3.5% in Experiment 1 and from 1.25 to 3.25% in Experiment 2. A group of 56 consumers evaluated various items on rib-eye (LL muscle trimmed of backfat) (Experiment 1) and on entire chops trimmed of backfat (Experiment 2). Data from Experiment 1 indicate that an increase in IMF level is associated with an increase in visual perception of fat and a corresponding decrease in the willingness to eat and purchase the meat, when expressed before tasting. The latter effect disappeared after the consumers had tasted the meat, probably due to a positive effect of increase IMF, up to 3.5%, on the perception of texture and taste. In Experiment 2, where entire chops were evaluated, the perception of visible fat was not affected by IMF level, probably due to the lack of variation in the level of intermuscular fat between the four IMF groups. The willingness to eat and purchase the meat were unaffected by IMF level, whereas the perception of texture and taste was enhanced with increased IMF levels up to 3.25%. The present data suggest that the acceptability of pork may be improved by increasing IMF level but: (1) this effect disappeared for IMF levels higher than 3.5%, which are associated with a high risk of meat rejection due to visible fat and (2) the positive effect of increased IMF probably holds true as long as it is not associated with an increase in the level of intermuscular fat.

1. Genetic parameters of body weight (BW), breast meat weight or yield (BRW, BRY) and abdominal fat weight or yield (FTW, FTY) were estimated in males and females originated from an experimental line selected for improving broiler carcase quality and its control line. 2. Mean heritabilities over both sexes of BW, FTW and FTY were 0.43, 0.56 and 0.63 respectively. Those of BRW and BRY were 0.53 and 0.65 respectively. 3. BW was unfavourably correlated with FTW (rg of 0.40) and to a lesser extent with FTY (rg of 0.12). BW was, as expected, highly correlated with BRW (rg 0.77), but a poor correlation was obtained with BRY (rg of 0.15). Selection for more breast yield should not reduce the leanness of the birds, with a genetic correlation between BRY and FTY of -0.15. 4. The variance explained by the maternal effects accounted for a rather small part of the total phenotypic variance (from 3% to 8% according to the trait), but ignoring these effects led to a significant overestimation of the heritabilities (by 11% to 19%). 5. Except for BRY, the heritability estimates differed between sexes, only moderately for BW but more for BRW, FTW and FTY. However, estimated genetic correlations between sexes were high (between 0.94 and 0.99) and in turn heritabilities of sexual dimorphism of the various traits very low (between 0.02 and 0.07). 6. A significant improvement of the genetic level for growth and carcase composition had been obtained in the selected line, with a mean genetic gain per generation of 0.12 sigma g, 0.13 sigma g and -0.30 sigma g for BW, BRY and FTY respectively.

SummaryThe control of tornato fruit weight during a crop cycle may be of commercial benefit. To assess the main causes of variability in the potential and actual fruit weight of mature fruit, both were measured together with the seed content on three tomato cultivars. Potential and actual weight were appraised on plants with single-fruit and seven-fruit trusses, respectively, until maturation of the fifteenth truss. Variability in the potential weight was mainly related to the cultivar, whereas differences between proximal and distal fruits were significant for beefsteak tomatoes only. In the long term, no truss effect on this potential could be detected. Under competitive growth conditions, the weight of distal fruits was reduced more than that of proximal fruits especially for the beefsteak cultivar. All trusses were not equally affected, inducing a large variability along the stem. The relation between fruit weight and seed number was closer as the range of variability in fruit weight was reduced, that...

The objective of the present work was to select stable well-characterized strains of #Verticillium dahliae$ that could be used as biological tools in genetic and plant-microbe interaction studies. Hyaline mutants, known for their stability in pathogenicity were chosen for the study. Diversity in pathogenicity was found among hyaline subclones obtained from a defoliating wild-type clone, but not within those from nondefoliating ones. Most subclones from the defoliating clone had parental pathotypes, but one (V7-2) exhibited weak pathogenicity. This subclone (V7-2), together with a highly virulent one (V7-7) deriving from the same defoliating parent clone (7), were selected for further characterization, because of their differences in pathogenicity. When studied on the basis of their growth requirements, the two subclones expressed marked differences. V7-7 grew better than V7-2 over a wider range of temperature conditions. Both subclones grew similarly in media supplemented with NH4 as nitrogen source, but in those with NO3, V7-7 grew more vigorously than V7-2 and only the former could grow when NO2 was used. In spite of these differences, the two subclones were found to belong to the same vegetative compatibility group, confirming their genetic proximity. These results highlight the physiological and genetic complexity inherent in #V. dahliae$. In view of their characteristics, the clones obtained in this study should prove to be valuable tools in furthering the understanding of genetic and host - #V. dahliae$ interactions. (Résumé d'auteur)

Monoclonal antibodies (mAbs) were prepared against a yam mosaic virus (YMV) isolate from the Cote d'Ivoire. Symptomatology, Western immunoblotting, and ELISA were used to discriminate 69 isolates of YMV originating from different Dioscorea species and from various yam producing areas. These isolates induced two types of symptoms, were of four different electrophoretic mobilities and formed two serogroups. These results suggest that at least six differetit groups of isolates exist, three of which infect the main cultivated species in various geographical areas while two others were from unusual samples in our collection. An isolate from ‘Pilimpikou Yam’ from Central Burkina Faso was serologically distinct. It is concluded that there is a significant variability among yam virus isolates which is unrelated to the origin of the isolate (geographic or host species). It is suggested that precautions should be taken in order to avoid international exchange of infected material.

G. RECORBET, C. STEINBERG AND C. ALABOUVETTE. 1996. Helix pomatia lectin, Concanavalin A, Wheat germ agglutinin and Tetragonolobus purpureas lectin were used to identify N-acetylgalactosamine, D-mannose, N-acetylglucosamine and L-fucose sugar residues, respectively, on the surface of microconidia of Fusarium oxysporum strains. On the basis of the use of FITC-labelled lectins, N-acetylglucosamine, N-acetylgalactosamine and D-mannose sugar residues were identified and did not vary qualitatively between the strains tested. L-fucose residues were not detected, whatever the strain tested. Agglutination experiments showed a quantitative variability in the carbohydrate residues detected with ConA and WGA within the F. oxysporum species. The agglutination responses of the isolates tested did not reflect either their pathogenicity or their host specificity.

9 pages, 5 figures, 2 tables.-- PMID: 7781619 [PubMed].-- PMCID: PMC398381., Retroviruses consist of populations of different but closely related genomes referred to as quasispecies. A high mutation rate coupled with extremely rapid replication cycles allows these sequences to be highly interconnected in a rapid equilibrium. It is not known if other retroelements can show a similar population structure. We show here that when the tobacco Tnt1 retrotransposon is expressed, its RNA is not a unique sequence but a population of different but closely related sequences. Nevertheless, this highly variable population is not in a rapid equilibrium and could not be considered as a quasispecies. We have thus named the structure presented by Tnt1 RNA quasispecies-like. We show that the expression of Tnt1 in different situations gives rise to different populations of Tnt1 RNA sequences, suggesting an adaptive capacity for this element. The analysis of the variability within the total genomic population of Tnt1 elements shows that mutations frequently occur in important regulatory elements and that defective elements are often produced. We discuss the implications that this population structure could have for Tnt1 regulation and evolution., We are extremely grateful to J.Gomez for suggesting that we should analyse Tntl variability and for very helpful discussions and useful comments on the manuscript. We thank H.Lucas, C.Robaglia and I.Small for critical reading of the manuscript. We also wish to thank A.Gabriel for sharing unpublished data with us. J.M.C. is supported by an INRA post-doctoral fellowship.

General criteria for the assignment of names to enzyme systems, regions of activity, isozyme loci and allozymes have been lacking in crucifer species. This paper proposes a standard nomenclature for seven isozyme systems in the three diploid species of U's triangle: Brassica nigra, B. oleracea and B. campestris. Gel/electrode buffers, which provided the best resolution for seven isozyme systems, acid phosphatase (APS), aconitase (ACO), leucine aminopeptidase (LAP), 6-phosphogluconate dehydrogenase (6 PGD), phosphoglucoisomerase (PGI), phosphoglucomutase (PGM), and triosephosphate isomerase (TPI), were proposed as standards. Isozyme genetic analysis was determined for B. oleracea and B. campestris from previous studies and by segregation of selfed progenies of heterozygous B. nigra plants. Several populations were studied and 148 allozymes at the 18 loci observed were described for the three species. Their relative mobility was studied using a pure line of oilseed rape as reference. The comparison of the different alleles within and between the species is discussed.

SUMMARYThe 4 species of ruminants (dromedary, zebu cattle, sheep and goat) in arid areas of Mauritania harboured Haemonchus spp. as the most frequent internal parasite. This was a rare situation where the 3 putative species, H. longistipes (dromedary), H. placet (zebu cattle) and H. contortus (sheep and goat) occurred sympatrically. The study was undertaken on hosts slaughtered at the Nouakchott abattoir, on the basis of monthly collection of worms. The environment was very unfavourable to H. placei and unfavourable to H. contortus, as intensity of infection remained low throughout the year, whereas infection in the dromedary was 10 to 20-fold higher. The survival strategies during the long, dry season were different: the surviving stages were either 4th-stage larvae in digesta (dromedaries), 4th-stage larvae either in digesta or mucosae (cattle), or 4th-stage larvae in mucosae and few adults (sheep and goats). The prolificacy of female worms, indicative of the potential to contaminate pastures, was similar for all Haemonchus spp. in the rainy season. H. longistipes behave differently during the pre-rainy season as no increase of prolificacy could be demonstrated as observed in the other species. Traits of vulvar morphology are considered as markers of ecological adaptation and were studied. The knobbed and smooth female morphs (in equal proportions) were the most frequent in H. longistipes, the knobbed morph out-numbered the other morphs in H. placei, and all 3 morphs were present in sheep and goats with the linguiform form being predominant. Genetic characterization of the 3 species was performed by means of Random Amplified Polymorphic DNA (RAPD). Three groups were obtained from analysis of these data: 1 group with individuals of H. contortus, 1 group with individuals of H. placei, and 1 group with individuals of H. longistipes. This indicated that, although the 3 species were valid, H. contortus and H. placei were more similar. Intraspecific variability was 2-fold higher in H. contortus than in the 2 other species. The ecological, morphological and genetical studies showed that H. longistipes, H. placei and H. contortus could be arranged in increasing order of variability.

Twenty-eight plum pox virus isolates from several European and Mediterranean countries were compared by electrophoretic mobility of their coat protein subunit measured by Electroblot Immuno-Assay (EBIA), antigenic properties of the N- and C-terminal parts of the coat protein and restriction fragment length polymorphism (RFLP) and analysis of polymerase chain reaction (PCR) amplification of the C-terminal part of the coat protein gene. Similar results were obtained by each of the three methods. These confirm the existence of the two major subgroups of PPV, and which we now propose to designate PPV-D and PPV-M, respectively.