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MAMMIFERTMAMMIFERT; absent

Pour augmenter la productivité du troupeau ovin français, l’INRA a créé la souche synthétique INRA 401 en croisant la race Berrichon du Cher (bonnes aptitudes bouchères mais peu prolifique, peu maternelle, toison blanche) avec la race Romanov (très prolifique, maternelle, mais faibles aptitudes bouchères et toison colorée). La procréation de 4 générations successives (1970 - 1980) a mis en évidence l’absence d’hétérosis et de régression de la taille de portée de la F1 à la F4. La lignée obtenue présente une taille moyenne de portée de 2 agneaux par mise bas (sur brebis de 3 ans), une excellente fertilité à contre-saison, une bonne viabilité des agneaux à la naissance. A partir de 1980, le troupeau a été soumis à la sélection, d’abord sur la prolificité seule puis sur la prolificité et la valeur laitière et, depuis 1989, sur prolificité, valeur laitière, caractères de croissance et caractères bouchers. La souche a été diffusée en fermes par la vente de béliers utilisés en croisement d’absorption sur brebis croisées Romanov x race locale, et ce sur 4 générations. Ce programme concernait en 1990, 152 élevages (28 000 brebis) réunis au sein d’une association des éleveurs utilisateurs : l’AUSI 401.

Chez les Mammifères, la différenciation sexuelle résulte d’une cascade complexe dont le premier acteur est le gène SRY, porté par le chromosome Y, qui masculinise la gonade indifférenciée. Cependant, certains individus, en l’absence de SRY, présentent un développement testiculaire et une réversion du sexe. Chez la chèvre, par exemple, la réversion du sexe d’individus XX en l’absence du gène SRY ou d’autres séquences du chromosome Y est étroitement liée à l’absence de corne (mutation motte) puisqu’aucun recombinant n’a jamais été observé. Ce syndrome, nommé PIS pour Polled Intersex Syndrome, est causé par des mutations dans un ou deux gènes autosomiques que nous avons localisés dans un premier temps à proximité de deux marqueurs microsatellites d’origine bovine sur le chromosome 1 caprin. Les cartes génétique, cytogénétique et physique de la région ont ensuite été construites à l’aide, d’une part, de banques d’ADN issues de chromosome 1 trié, des bandes 1q42, 1q43 et 1q44 microdisséquées et de grands fragments (BAC) et, d’autre part, de la cartographie comparée avec les gènes ou EST (expressed sequence tags) localisés dans la région humaine homologue. Ces différentes approches ont permis de localiser le gène PIS au sein d’un contig de 1,5 Mb, dans une région de 100 kb autour d’un marqueur microsatellite.

Up to now, genetic selection in cattle has been directed in favour of muscle growth, which changes muscle characteristics, and hence meat quality. One key concern, that now needs examination, is to understand the relationships between muscle growth and muscle characteristics related to meat quality. To achieve such a goal, muscles of divergently selected animals were analysed by three complementary approaches: (i) determination of muscle biochemical characteristics, (ii) identification of differentially expressed genes using transcriptomic and proteomic tools, (iii) identification of Single Nucleotide Polymorphisms (SNP) within candidate genes.

Chantier qualité GA; International audience; We mapped six genes (EIF4G3, HSP90, RBBP6, IL8, TERT, and TERC) on the chromosomes of Equus caballus, Equus asinus, Equus grevyi, and Equus burchelli by fluorescence in situ hybridization. Our results add six type I markers to the cytogenetic map of these species and provide new information on the comparative genomics of the genus Equus.

Summary. Five new bovine (TG)n microsatellite sequences were characterized. During the screening procedure, one-third of the clones had essentially the same flanking sequences. A fast technique was devised to eliminate these clones.

Restriction fragment length polymorphism was studied in an ELA typed horse family which included a stallion, a mare with two full-sibs, another mare with three full-sibs and, in addition, three paternal half-sibs. DNA samples from all individuals were investigated by Southern blot analysis using three restriction enzymes (EcoRI, HindIII or TaqI) and human cDNA class I, class II (DR beta) and class III (C4) probes. In addition, a genomic class II DQ alpha probe was used. Fragments hybridized with the various probes revealed the existence of DNA sequences homologous to HLA class I, DR beta, DQ alpha and C4 genes in the horse. Polymorphic fragments were found when DNA was hybridized with class I and class II probes irrespective of the enzyme used; but hybridization with the C4 probe did not reveal variability. All polymorphic fragments segregated according to the ELA serological specificities, thus indicating a close linkage between the different revealed subregions. Banding patterns suggest that the horse possesses about 20-30 class I genes, probably more than one DR beta and DQ alpha genes and possibly only one C4 gene. The high degree of polymorphism observed suggests that molecular DNA typing may represent a potentially powerful aid to decision in parentage control determination.

Segregation at the loci coding for the K88ab and K88ac small intestinal receptors to E. coli adhesins (K88abR, K88acR) and at the transferrin (TF) locus was studied in 38 pig families including 273 piglets. The TF locus showed a segregation deviation towards the B variant while each of the K88 receptors behaved as a single autosomal dominant gene. Recombinants between K88abR and K88acR provide evidence that they are under the control of two different loci. Thirty-two triple backcross families were selected to test linkage and estimate recombination rates (theta). Our results demonstrate that the two K88 receptor loci are closely linked (theta = 0.02) with a maximum lod score value (Zm) of 46.0. In addition, they are linked to the TF locus, theta = 0.14, Zm = 19.6 for the K88abR locus and theta = 0.16, Zm = 17.9 for the K88acR locus. The estimated recombination rates, smaller in males than in females, are consistent with the order TF-K88abR-K88acR. This linkage thus localizes the K88 loci, as the TF locus, on chromosome 13.

158 Belgian Saddlebreds, 130 Belgian Trotters, 108 Belgian Draft horses and 92 Shetland ponies have been typed for serologically defined antigens at the ELA and ELY systems. Gene frequencies were estimated in each breed for the internationally established ELA, ELY-1 and ELY-2 alleles as well as for locally assigned additional ELA markers and for subtypes of ELA-W3, W9 and W11. The distribution of ELA alleles was in agreement with the expected Hardy-Weinberg equilibrium for the 4 horse breeds described here. Differences in gene frequencies between these main Belgian horse populations were observed.

International audience

Summary. The workshop consisted of 12 monthly cell exchanges of full-sibling families among the 10 participating laboratories. A total of 33 parents, 52 offspring and five unrelated horses were typed by each laboratory using local antisera. The raw data were submitted for central analysis before any identification of the animals was revealed. Confidence derived from the consistent agreement between the laboratories on the assignment and segregation of the first 10 ELA-W specificities led to the removal of the W (workshop) notation and acceptance of full status as locus A antigens. The seemingly supertypic W11 specificity, however, remained unchanged. Ten additional specificities were seen to segregate with the ELA system, suggesting either splits of previously described specificities or products of linked loci. The workshop (W) notation was given to the 10 specificities W12-W21, befitting their status as specificities under study. The previously described ELY-1.1 specificity, characterized by segregation independent from the ELA system, was confirmed along with a new specificity, ELY-1.2, which behaves as an allele of ELY-1.1. For informative families, the two specificities showed codominant expression and appeared to constitute a closed, autosomal system. The ELY-2.1 specificity was confirmed to segregate independently from the ELA-A and ELY-1 loci.

In sheep, susceptibility to scrapie is mainly influenced by polymorphisms of the PrP gene. In goats, there are to date few data related to scrapie susceptibility association with PrP gene polymorphisms. In this study, we first investigated PrP gene polymorphisms of the French Alpine and Saanen breeds. Based on PrP gene open reading frame sequencing of artificial insemination bucks (n=404), six encoding mutations were identified at codons 127, 142, 154, 211, 222 and 240. However, only seven haplotypes could be detected: four (GIH154RQS, GIRQ211QS, GIRRK222S and GIRRQP240) derived from the wild-type allele (G127I142R154R211Q222S240) by a single-codon mutation, and two (S127IRRQP240 and GM142RRQP240) by a double-codon mutation. A case–control study was then implemented in a highly affected Alpine and Saanen breed herd (90 cases/164 controls). Mutations at codon 142 (I/M), 154 (R/H), 211 (R/Q) and 222 (Q/K) were found to induce a significant degree of protection towards natural scrapie infection. Compared with the baseline homozygote wild-type genotype I142R154R211Q222/IRRQ goats, the odds of scrapie cases in IRQ211Q/IRRQ and IRRK222/IRRQ heterozygous animals were significantly lower [odds ratio (OR)=0.133, PP142RRQ/IRRQ genotype was only protective (OR=0.243, P=0.0186) in goats also PP240 homozygous at codon 240. However, mutated allele frequencies in French Alpine and Saanen breeds were low (0.5–18.5 %), which prevent us from assessing the influence of all the possible genotypes in natural exposure conditions.

Fourteen monoclonal antibodies recognizing monomorphic and polymorphic epitopes on class I and class II antigens of the human MHC have been assayed on lymphocytes of a panel of 20-150 BoLA typed bovine animals from 12 different breeds. Some monomorphic antibodies cross-reacted and others did not. Two polymorphic monoclonal antibodies in man recognize a polymorphism in cows that follows allospecificities (BoLA-w3, w9) already described. Immunoprecipitation experiments with monomorphic anti-B2m and anti-HLA-DR monoclonal antibodies have shown that these cross-reactions concern BoLA antigens. They also revealed that Ia-like antigens in cattle present the same two chain features characterized in other species.

International audience; To assess risk for cattle-to-human transmission of prions that cause uncommon forms of bovine spongiform encephalopathy (BSE), we inoculated mice expressing human PrP Met with fi eld isolates. Unlike classical BSE agent, L-type prions appeared to propagate in these mice with no obvious transmission barrier. H-type prions failed to infect the mice.

We report an extended river buffalo (Bubalus bubalis, 2n = 50; BBU) cytogenetic map including 388 loci, of which 68 have been FISH-mapped on autosomes in the present study. Ovine and caprine BAC clones containing both type I loci (known genes) and type II loci (simple sequence repeats (SRs), microsatellite marker, sequence-tagged sites (STSs)), previously assigned to sheep chromosomes, have been localized on R-banded river buffalo chromosomes (BBU), which expands the cytogenetic map of this important domestic species and increases our knowledge of the physical organization of its genome. The loci mapped in the present study correspond to loci already localized on homoeologous cattle (and sheep) chromosomes and chromosome bands, further confirming the high degree of chromosome homoeologies among bovids. The comparison of the integrated cytogenetic maps of BBU2p/BBU10 and BBU5p/BBU16 with those of human chromosomes (HSA) 6 and 11, respectively, identified, at least, nine conserved chromosome segments in each case and complex rearrangements differentiating river buffalo (and cattle) and human chromosomes.

Several recent studies have shown that genes specifically expressed by the oocyte are subject to rapid evolution, in particular via gene duplication mechanisms. In the present work, we have focused our attention on a family of genes, specific to eutherian mammals, that are located in unstable genomic regions. We have identified two genes specifically expressed in the mouse oocyte: Khdc1a (KH homology domain containing 1a, also named Ndg1 for Nur 77 downstream gene 1, a target gene of the Nur77 orphan receptor), and another gene structurally related to Khdc1a that we have renamed Khdc1b. In this paper, we show that Khdc1a and Khdc1b belong to a family of several members including the so-called developmental pluripotency A5 (Dppa5) genes, the cat/dog oocyte expressed protein (cat OOEP and dog OOEP) genes, and the ES cell-associated transcript 1 (Ecat1) genes. These genes encode structurally related proteins that are characterized by an atypical RNA-binding KH domain and are specifically expressed in oocytes and/or embryonic stem cells. They are absent in fish, bird, and marsupial genomes and thus seem to have first appeared in eutherian mammals, in which they have evolved rapidly. They are located in a single syntenic region in all mammalian genomes studied, except in rodents, in which a synteny rupture due to a paracentric inversion has separated this gene family into two genomic regions and seems to be associated with increased instability in these regions. Overall, we have identified and characterized a novel family of oocyte and/or embryonic stem cell-specific genes encoding proteins that share an atypical KH RNA-binding domain and that have evolved rapidly since their emergence in eutherian mammalian genomes.

The objective of this study was to characterize the body composition, nutrient utilization, energy storage sites and major economic traits of trout selected at pan-size for or against body weight corrected muscle fat content (fat line, FL and lean line, LL respectively). The study focused on the effect of selection in fish size larger than the size where selection has been applied, and the possible effect of diet composition on the differences between lines. FL and LL trout were fed two diets differing for energy content and protein/lipid ratio during 62-days. The feeding trial (day 370 to day 432) started with 327g fish. Dietary protein and lipid contents were 58.7% and 8.3% dry matter (DM) respectively for diet D8 and 47.7% and 26.7% DM for diet D27. Growth, feed intake, feed utilization and traits related to body shape and composition were recorded. In both lines diet D27 improved growth rate, feed efficiency, protein retention and fat gain ( P P = 0.02, no line × diet interaction). The main differences between lines were observed in lipid gain and retention. Values of lipid retention (% of intake) were higher in FL fish ( P = 0.04) regardless of diet, and suggested a greater ability of FL fish in de novo lipid synthesis. Fat deposition (% of weight gain) was greater in FL fish during the trial and occurred in fillet ( P = 0.04), on internal side of the belly flap ( P = 0.04), as well as in other sites of the body, as indicated by higher overall body lipid content at day 432 ( P = 0.02, no line × diet interaction). Nevertheless, carcass and fillet yields were not different between lines regardless of diet. In conclusion, selection for body weight corrected muscle fat content modified the ability of the fish to utilize nutrients and to store more or less fat in the different body sites. The differences were expressed in a large range of dietary protein/fat ratios. Line × diet interactions were recorded for a very limited number of traits, indicating that the combined use of genetic and nutritional tools should be efficient to manage carcass quality (growth, body shape, processing yields) and fat deposition (quantity and body location) in trout, with no need to adapt diet formulation according to lines .

In this study, the potential association of PrP genotypes with health and productive traits was investigated. Data were recorded on animals of the INRA 401 breed from the Bourges-La Sapinière INRA experimental farm. The population consisted of 30 rams and 852 ewes, which produced 1310 lambs. The animals were categorized into three PrP genotype classes: ARR homozygous, ARR heterozygous, and animals without any ARR allele. Two analyses differing in the approach considered were carried out. Firstly, the potential association of the PrP genotype with disease (Salmonella resistance) and production (wool and carcass) traits was studied. The data used included 1042, 1043 and 1013 genotyped animals for the Salmonella resistance, wool and carcass traits, respectively. The different traits were analyzed using an animal model, where the PrP genotype effect was included as a fixed effect. Association analyses do not indicate any evidence of an effect of PrP genotypes on traits studied in this breed. Secondly, a quantitative trait loci (QTL) detection approach using the PRNP gene as a marker was applied on ovine chromosome 13. Interval mapping was used. Evidence for one QTL affecting mean fiber diameter was found at 25 cM from the PRNP gene. However, a linkage between PRNP and this QTL does not imply unfavorable linkage disequilibrium for PRNP selection purposes.

Centromere repositioning (CR) is a recently discovered biological phenomenon consisting of the emergence of a new centromere along a chromosome and the inactivation of the old one. After a CR, the primary constriction and the centromeric function are localized in a new position while the order of physical markers on the chromosome remains unchanged. These events profoundly affect chromosomal architecture. Since horses, asses, and zebras, whose evolutionary divergence is relatively recent, show remarkable morphological similarity and capacity to interbreed despite their chromosomes differing considerably, we investigated the role of CR in the karyotype evolution of the genus Equus. Using appropriate panels of BAC clones in FISH experiments, we compared the centromere position and marker order arrangement among orthologous chromosomes of Burchelli’s zebra (Equus burchelli), donkey (Equus asinus), and horse (Equus caballus). Surprisingly, at least eight CRs took place during the evolution of this genus. Even more surprisingly, five cases of CR have occurred in the donkey after its divergence from zebra, that is, in a very short evolutionary time (approximately 1 million years).These findings suggest that in some species the CR phenomenon could have played an important role in karyotype shaping, with potential consequences on population dynamics and speciation. D 2005 Elsevier Inc. All rights reserved.

In goats, the PIS (polled intersex syndrome) mutation is responsible for both the absence of horns in males and females and sex-reversal affecting exclusively XX individuals. The mode of inheritance is dominant for the polled trait and recessive for sex-reversal. In XX PIS-/- mutants, the expression of testis-specific genes is observed very precociously during gonad development. Nevertheless, a delay of 4–5 days is observed in comparison with normal testis differentiation in XY males. By positional cloning, we demonstrate that the PIS mutation is an 11.7-kb regulatory-deletion affecting the expression of two genes, PISRT1 and FOXL2 which could act synergistically to promote ovarian differentiation. The transcriptional extinction of these two genes leads, very early, to testis-formation in XX homozygous PIS-/- mutants. According to their expression profiles and bibliographic data, we propose that FOXL2 may be an ovary-differentiating gene, and the non-coding RNA PISRT1, an anti-testis factor repressing SOX9, a key regulator of testis differentiation. Under this hypothesis, SRY, the testis-determining factor would inhibit these two genes in the gonads of XY males, to ensure testis differentiation.

Comparative FISH-mapping among Y chromosomes of cattle (Bos taurus, 2n = 60, BTA, submetacentric Y chromosome), zebu (Bos indicus, 2n = 60, BIN, acrocentric Y chromosome but with visible small p-arms), river buffalo (Bubalus bubalis, 2n = 50, BBU, acrocentric Y chromosome), sheep (Ovis aries, 2n = 54, OAR, small metacentric Y chromosome) and goat (Capra hircus, 2n = 60, CHI, Y-chromosome as in sheep) was performed to extend the existing cytogenetic maps and improve the understanding of karyotype evolution of these small chromosomes in bovids. C- and R-banding comparison were also performed and both bovine and caprine BAC clones containing the SRY, ZFY, UMN0504, UMN0301, UMN0304 and DYZ10 loci in cattle and DXYS3 and SLC25A6 in goat were hybridized on R-banded chromosomes by FISH. The main results were the following: (a) Y-chromosomes of all species show a typical distal positive C-band which seems to be located at the same region of the typical distal R-band positive; (b) the PAR is located at the telomeres but close to both R-band positive and ZFY in all species; (c) ZFY is located opposite SRYand on different arms of BTA, BIN, OAR/CHI Y chromosomes and distal (but centromeric to ZFY) in BBU-Y; (d) BTA-Y and BIN-Y differ as a result of a centromere transposition or pericentric inversion since they retain the same gene order along their distal chromosome regions and have chromosome arms of different size; (e) BTA-Y and BBU-Y differ in a pericentric inversion with a concomitant loss or gain of heterochromatin; (f) OAR/CHI-Y differs from BBU-Y for a pericentric inversion with a major loss of heterochromatin and from BTA and BIN for a centromere transposition followed by the loss of heterochromatin.

International audience; A comparative pathology and mapping strategy was used to initiate a study on two bovine genetic diseases: arthrogryposis-palatoschisis and progressive ataxia, which affect mainly Charolais cattle. Bibliographic studies provided information on the pathology of these diseases, which helped to define similar diseases in other species. Animals affected by bovine arthrogryposis-palatoschisis display similar symptoms to those of muscular dysgenesis, mouse mutants and animals with progressive ataxia to those of Long Evans Shaker rat mutants. Candidate regions are respectively human chromosome 1q32 (BTA16) containing the gene CACNA1S and human chromosome 18q23 (BTA24) containing the gene myelin basic protein (MBP). Primer pairs were designed for 15 loci around each candidate gene, in a region of about 20 megabases and were used to screen a bovine Bacterial Artificial Chromosome (BAC) library. Eighteen microsatellites were found in the identified BAC clones, 11 on BTA24 and seven on BTA16. The genes and microsatellites were mapped by radiation hybrid (RH) analysis and a RH map was obtained for each region with 18 new localizations on BTA16 and 23 on BTA24. Comparative human-bovine analysis of the MBP region shows a good conservation of gene order while that of the CACNA1S region shows several breakpoints.

The expression of casein genes is specific to the mammary gland and maximal during lactation. However, among the numerous mammary cell lines described so far, only a few express some casein genes. The regulatory regions of casein genes have been largely described but the mechanisms explaining the mammary specific expression of these genes, and their silencing in most mammary cell lines, have not yet been fully elucidated. To test the hypothesis that the nuclear location of the casein genes may affect their expression, we transfected HC11 mouse mammary cell line with a 100 kb DNA fragment surrounding the rabbit alpha S1 casein gene. We derived stable clones which express or not the transfected rabbit casein gene, in the same cellular context, independently of the number of transgene copies. Metaphase spreads were prepared from the different clones and the transfected genes were localized. Unexpectedly, we observed that in the original HC11 cell line the number of chromosomes per metaphase spread is close to 80, suggesting that HC11 cells have undergone a duplication event, since the mouse karyotype is 2n = 40. In alpha S1 casein expressing cells, the expression level does not clearly correlate with a localization of the transfected DNA proximal to the centromeres or the telomeres. Analysis of the localization of the transfected DNA in nuclear halos allows us to conclude that when expressed, transfected DNA is more closely linked to the nuclear matrix. The next step will be to study the attachment of the endogenous casein gene in mammary nuclei during lactation.

International audience; Rabbit, a domestic species exploited both in animal production and medical research has only recently begun to be included in gene mapping projects, in particular by the French National Institute of Agronomics. By 2002, less than 60 genes had been precisely localised on rabbit chromosomes, which led us to start a large-scale project on gene mapping in rabbit with the publication of 133 gene localisations in 2003 (Chantry-Darmon et al., 2003). Here, we report the localisation of 102 new genes resulting in good coverage of the rabbit genome and an eight-fold enrichment of the gene map. In addition, we have detected a new conserved segment between rabbit chromosome 4q15.3 and part of human chromosome 22 and thus improved the comparative map with the human genome.

Cloning by nuclear transfer has made it possible to produce genetically identical animals in terms of nuclear DNA content. Recent molecular biology tools are offering scientific ways to get an insight into the identity issues, by exploring and comparing genomes of cloned animals in order to test their genetic identity and methylation differences. We have initiated a study to compare genomic DNA of bovine adult clones, of normal phenotype. We have used, in parallel, the AFLP technique (amplification fragment length polymorphism) and one of its variant, MSAP (methylation-sensitive amplification polymorphism). We are also investigating other techniques leading to the detection of sequence polymorphisms between two genomes based on genomes hybridisation. We chose the representational difference analysis (RDA) methods that can be combined with mismatch-specific recognition or mismatch binding property of some proteins (CEL I, MutS). We plan to use these RDA methods for genome-wide detection of subtle mutations, then to focus on changes affecting the methylation status of promoting genomic regions in abnormal clones. This will be achieved using MSAP with NotI and applying, in parallel, the RLGS (restriction landmark genome scanning) technique. This study will hopefully improve the molecular and functional characterizations of these "new animals."

"Chantier qualité spécifique "Auteurs Externes" département de Génétique animale : uniquement liaison auteur au référentiel HR-Access "; International audience; Macro-arrays, on which 1339 human skeletal muscle cDNA clone inserts had been spotted as PCR products, were used to make large-scale measurement of gene expression in bovine muscles during ontogenesis. Ten complex cDNA targets derived from two mixed muscle samples, Rectus abdominis (rather red oxidative muscle, RA) and Semitendinosus (rather white glycolytic muscle, ST), were taken from foetuses at 4 different stages (110, 180, 210, and 260 days post-conception) and from 15-month-old young bulls to generate differential expression patterns. Each sample analysed was prepared from a pool of RNA extracted from muscle tissues sampled from at least 6 different animals. Approximately 200 expression signals were validated and taken into account to provide a first "bovine" muscle gene repertoire. Despite the relatively small number of probes and the heterologous approach, this made it possible to identify up to 7 genes differentially expressed between RA and ST, depending on age. From 110 days post-conception to 15 months of age, differences in the expression levels of 110 genes were detected in the four comparisons between two consecutive ages. By comparing 260 days post-conception foetal muscles and adult muscles, up to 87 genes were overexpressed, whereas only 7 genes were shown to be down-regulated. Among these genes, 33% have unknown biological functions. Taken together, the results reported here underline the importance of the last three months of gestation in muscle myogenesis, and highlight new genes involved in this process.

Summary The genetic structure and relationships among 18 local Southwest European beef cattle breeds (10 from Spain, five from Portugal and three from France) have been inferred from 16 DNA microsatellite loci, by using F-statistics, for conservation purposes. Level of apparent breed differentiation is considerable and multilocus FST values indicate that around 6.8% of the total genetic variation could be explained by breed differences and the remaining 93.2% by differences among individuals. For countries of origin, the French breeds were those that showed a higher genetic uniformity. All breeds, except the

Prion diseases are fatal neurodegenerative disorders of animals and humans that are characterized by the conversion of the host-encoded prion protein (PrP) to an abnormal isoform. In several species, including humans, polymorphisms in the gene encoding the PrP protein tightly control susceptibility of individuals toward this disease. In the present study we show that Rov cells expressing an ovine PrP allele ( VRQ PrP) associated with high susceptibility of sheep to scrapie were very sensitive to sheep prion transmission and replicated the agent to high titers. In contrast, we did not find any evidence of infection when Rov cells expressed similar levels of a PrP variant ( ARR PrP) linked to resistance. Our data provide the first direct evidence that natural PrP polymorphisms may affect prion susceptibility by controlling prion replication at the cell level. The study of how PrP polymorphisms influence the genetic control of prion propagation in cultured Rov cells may help elucidate basic mechanisms of prion replication.

Our on-going goal is to improve and update the comparative genome organization between cattle and man but also among the most detailed mammalian species genomes i.e. cattle, mouse, rat and pig. In this work, we localized 195 genes in cattle and checked all human/bovine non-concordant localizations found in the literature. Next, we compiled all the genes mapped in cattle, goat, sheep and pig (2,166) for which the human ortholog with its chromosomal position is known, added corresponding data in mouse and rat, and ordered the genes relatively to the human genome sequence. We estimate that our compilation provides bovine mapping information for about 89% of the human autosomes. Thus, a near complete, overall and detailed picture of the number, distribution and extent of bovine conserved syntenies (regardless of gene order) on human R-banded autosomes is proposed as well as a comparison with mouse, rat and pig genomes.

The cysteine-rich secretory protein (CRISP) family consists of three members called acidic epididymal glycoprotein 1 (AEG1), AEG2, and testis-specific protein 1 (TPX1), which share 16 conserved cysteine residues at their C-termini. The CRISP proteins are primarily expressed in different sections of the male genital tract and are thought to mediate cell-cell interactions of male germ cells with other cells during sperm maturation or during fertilization. Therefore, their genes are of interest as candidate genes for inherited male fertility dysfunctions and as putative quantitative trait loci for male fertility traits. In this report, the cloning and DNA sequence of 137 kb of horse genomic DNA from equine chromosome 20q22 containing the closely linked equine TPX1 and AEG2 genes are described. The equine TPX1 gene consists of ten exons spanning 18 kb while the AEG2 gene consists of eight exons that are spread over 24 kb. The expression of these two genes was investigated in several tissues by reverse transcription polymerase chain reaction analysis and Western blotting. Comparative genome analysis between horse, human, and mouse indicates that all three CRISP genes are clustered on one chromosomal location, which shows conserved synteny between these species.

International audience; Lactose is the major sugar present in milk and an important osmotic regulator of lactation. It is digested by intestinal lactase, an enzyme expressed in new-borns. Its activity declines following weaning. As a result, adult mammals are normally lactose-intolerant and more than 75% of the human adult population suffers from lactase deficiency. A reduction in milk lactose content could be beneficial for nutritional but also agricultural and industrial purposes (less volume to transport, better milk coagulation, less effluent production). Several attempts to create transgenic mice producing milk with modified carbohydrate compositions have recently been described. Depending on whether these modifications resulted from an alteration of lactose synthesis or from lactose hydrolysis, striking physiological differences are observed.; Diminution in vivo de la teneur du lait en lactose : intérêt, stratégies et conséquences physiologiques. Le lactose est le principal sucre du lait et un important régulateur osmotique de la lactation. Il est digéré par la lactase intestinale, enzyme exprimée chez les nouveau-nés dont l'activité décroît après le sevrage. De fait, les mammifères adultes sont normalement intolérants au lactose et plus de 75 % de la population adulte mondiale souffre d'hypolactasia. Une diminution de la teneur en lactose du lait serait bénéfique d'un point de vue nutritionnel mais également pour l'agriculture et l'industrie (moins de volume à transporter, meilleure coagulation et moins de rejets). Plusieurs approches ont permis d'obtenir des souris transgéniques produisant un lait dont la composition en carbohydrates était modifiée. Selon que la cible de ces modifications était la synthèse du lactose ou ce sucre lui-même, les conséquences physiologiques étaient fort différentes.

Relative quantitative reverse transcription-polymerase chain reaction (rqRT-PCR), which allows an accurate quantification of the amount of mRNA in samples potentially differing in the quality of their RNA preparation, was used to quantify lipoprotein lipase (LPL) mRNA in ovine adipose tissue. A comparative evaluation of four rqRT-PCR procedures was carried out. The amount of LPL mRNA was assayed relative to either that of gamma-actin (ACT) or cyclophilin (CYC) mRNA, used as endogenous standard. Independent (INACT and INCYC procedures) or simultaneous (COACT and COCYC procedures) amplifications have been compared. Fluorescently labelled primers yielded PCR products which were quantitatively analysed using an automated DNA sequencer. After optimizing the PCR cycle number and verifying that the amounts of ACT and CYC mRNA varied only weakly according to the nutritional conditions studied, we have tested the ability of the four procedures to quantify specific variations in LPL mRNA. The repeatability of each step and the overall assay reproducibility were also examined. The COACT and INCYC procedures were finally retained to accurately quantify LPL mRNA in AT from nine underfed or refed ewes, and gave highly correlated results (r=0.98, p

The whey acidic protein (WAP) is the major whey protein of rodent, rabbit and camel. Recently, it was identified in the milk of swine ( Simpson et al., 1998 . J. Mol. Endocrinol. 20, 27–35). In this paper, the cloning of the pig WAP cDNA and of bacterial artificial chromosome (BAC) construct containing the entire porcine WAP gene is reported. The comparison of the coding sequence of the pig WAP gene to rodent or lagomorph WAP sequence already published demonstrated that only exon sequences are partially conserved. The porcine WAP gene was localized on the subtelomeric region of the chromosome 18. The estimation of the expression of the swine WAP gene in the mammary gland from lactating animals revealed a high level of expression. In order to compare the expression level of the porcine WAP gene from the large genomic fragment which contained 70 kb downstream and 50 kb upstream the pig WAP gene or the smaller one (1 kb downstream and 2.4 kb upstream), these two genomic fragments were transfected in HC11 cell line. The BAC construct was expressed 15 times higher than the plasmid when reported to the integrated copy number. This report suggests that the HC11 cell line is a useful tool to identify the regulatory sequences of milk protein genes.

Forty autosomal type I loci earlier mapped in goat were comparatively FISH mapped on river buffalo (BBU) and sheep (OAR) chromosomes, noticeably extending the physical map in these two economically important bovids. All loci map on homoeologous chromosomes and chromosome bands, with the exception of COL9A1 mapping on BBU10 (homoeologous to cattle/goat chromosome 9) and OAR9 (homoeologous to cattle/goat chromosome 14). A FISH mapping control with COL9A1 on both cattle and goat chromosomes gave the same results as those obtained in river buffalo and sheep, respectively. Direct G- and R-banding comparisons between Bovinae (cattle and river buffalo) and Caprinae (sheep and goat) chromosomes 9 and 14 confirmed that a simple translocation of a small pericentromeric region occurred between the two chromosomes. Comparisons between physical maps obtained in river buffalo and sheep with those reported in sixteen human chromosomes revealed complex chromosome rearrangements (mainly translocations and inversions) differentiating bovids (Artiodactyls) from humans (Primates).

National audience; La transgenèse permet d’introduire dans le génome d’un animal un fragment d’ADN qui sera ensuite transmis de génération en génération. Elle utilise différentes approches méthodologiques. Certaines, encore limitées à peu d’espèces, permettent des modifications très fines du génome. La transgenèse, associée au développement de la biologie moléculaire, offre des applications multiples tant dans la recherche fondamentale qu’appliquée. Elle est de fait devenue un outil indispensable pour l’analyse de la régulation de l’expression des gènes et la compréhension de leur fonction.

We have sequenced to high levels of accuracy 714-kb and 233-kb regions of the mouse and bovine X-inactivation centers (Xic), respectively, centered on the Xist gene. This has provided the basis for a fully annotated comparative analysis of the mouse Xic with the 2.3-Mb orthologous region in human and has allowed a three-way species comparison of the core central region, including theXist gene. These comparisons have revealed conserved genes, both coding and noncoding, conserved CpG islands and, more surprisingly, conserved pseudogenes. The distribution of repeated elements, especially LINE repeats, in the mouse Xic region when compared to the rest of the genome does not support the hypothesis of a role for these repeat elements in the spreading of X inactivation. Interestingly, an asymmetric distribution of LINE elements on the two DNA strands was observed in the three species, not only within introns but also in intergenic regions. This feature is suggestive of important transcriptional activity within these intergenic regions. In silico prediction followed by experimental analysis has allowed four new genes, Cnbp2, Ftx, Jpx, and Ppnx, to be identified and novel, widespread, complex, and apparently noncoding transcriptional activity to be characterized in a region 5′ of Xist that was recently shown to attract histone modification early after the onset of X inactivation.[The sequence data described in this paper have been submitted to the EMBL data library under accession nos. AJ421478, AJ421479, AJ421480, andAJ421481. Online supplemental data are available athttp://pbil.univ-lyon1.fr/datasets/Xic2002/data.html andwww.genome.org.]

International audience; The purpose of this study was to generate repetitive DNA sequence probes for the analysis of interphase nuclei by fluorescent in situ hybridisation (FISH). Such probes are useful for the diagnosis of chromosomal abnormalities in bovine preimplanted embryos. Of the seven probes (E1A, E4A, Ba, H1A, W18, W22, W5) that were generated and partially sequenced, five corresponded to previously described Bos taurus repetitive DNA (E1A, E4A, Ba, W18, W5), one probe (W22) shared no homology with other DNA sequences and one (H1A) displayed a significant homology with Rattus norvegicus mRNA for secretin receptor transmembrane domain 3. Fluorescent in situ hybridisation was performed on metaphase bovine fibroblast cells and showed that five of the seven probes hybridised most centromeres (E1A, E4A, Ba, W18, W22), one labelled the arms of all chromosomes (W5) and the H1A probe was specific to three chromosomes (ch14, ch20, and ch25). Moreover, FISH with H1A resulted in interpretable signals on interphase nuclei in 88% of the cases, while the other probes yielded only dispersed overlapping signals.; Génération d'une sonde bovine à séquences répétées pour l'analyse en FISH des noyaux bovins en interphase. L'objectif de cette étude est d'isoler des sondes nucléiques bovines spécifiques d'un faible nombre de chromosomes permettant une analyse par hybridation in situ fluorescente (FISH) des noyaux en interphase. De telles sondes présentent un outil précieux pour l'étude d'anomalies chromosomiques d'embryons chez les bovins. Sept sondes ont été générées (E1A, E4A, Ba, H1A, W18, W22, W5) et partiellement séquencées : cinq d'entre elles correspondent à des séquences répétées d'ADN génomique bovin déjà décrites (E1A, E4A, Ba, W18, W5), la sonde W22 ne présente à ce jour aucune homologie avec les séquences connues dans "Genbank" et la dernière, H1A (3,5 kb isolée après digestion par l'enzyme HindIII) présente une homologie significative sur 158 paires de base avec l'ARNm codant pour le 3e domaine transmembranaire du récepteur de la secrétine de rat (Rattus norvegicus). L'hybridation in situ fluorescente sur des fibroblastes bovins en métaphase a montré que cinq sondes (E1A, E4A, Ba, W18, W22) hybrident la plupart des centromères, que la sonde W5 marque les bras de tous les chromosomes, et que la sonde H1A est spécifique de trois chromosomes bovins (ch14, ch20 et ch25). De plus, sur noyaux interphasiques, l'utilisation de H1A a permis d'obtenir des signaux interprétables dans 88 % des cas, contrairement aux autres sondes qui donnent des signaux superposés difficiles à interpréter.

A series of 31 marker genes (one per chromosome) were localized precisely to both Q- and R-banded bovine chromosomes by fluorescence in situ hybridization (FISH), as a contribution to the revised chromosome nomenclature of the three major domestic bovidae (cattle, sheep and goat). All marker genes except one (LDHA) are taken from the Texas Nomenclature of the cattle karyotype published in 1996. Homologous probes for each marker gene were obtained by screening a bovine BAC library by PCR with specific primer pairs. After labeling with biotin, each probe preparation was divided into two fractions and hybridized to bovine chromosomes identified either by Q or R banding. Clear signals and good quality band patterns were observed in all cases. Results of the two series of hybridizations are totally concordant both for Q and R band chromosome numbering and precise band localization. This work permits an unambiguous correlation between the Q/G- and R-banded 31 bovine chromosomes, including chromosomes 25, 27 and 29 which remained unresolved in the Texas Nomenclature (1996). Hybridization of the chromosome 29 marker gene to metaphase spreads from a 1;29 Robertsonian translocation bull carrier showed a positive signal on the short arm of this rearranged chromosome, confirming that the numbering of this long-known translocation in cattle is correct when referring to the Texas Nomenclature (1996). Taking into account that cattle, goat and sheep have very similar banded karyotypes, the data presented here will help to establish a definite and complete reference chromosome nomenclature for these species.

Comparative FISH mapping of river buffalo (Bubalus bubalis, BBU), sheep (Ovis aries, OAR), and cattle (Bos taurus, BTA) X chromosomes revealed homologies and divergences between the X chromosomes in the subfamilies Bovinae and Caprinae. Twenty-four and 17 loci were assigned for the first time to BBU X and OAR X, respectively, noticeably extending the physical map in these two species. Seventeen loci (four of which for the first time) were also FISH mapped to BTA X and used for comparative mapping studies on the three species, which show three morphologically different X chromosomes: an acrocentric (BBU X), an acrocentric with distinct short arms (OAR X), and a submetacentric (BTA X). The same order of loci were found on BTA X and BBU X, suggesting that a centromere transposition, with loss (cattle) or acquisition (river buffalo) of constitutive heterochromatin, differentiated the X chromosomes of these two bovids. Comparison of bovine (cattle and river buffalo) and caprine (sheep) X chromosomes revealed at least five common chromosome segments, suggesting that multiple transpositions, with retention or loss of constitutive heterochromatin, had occurred during their karyotypic evolution.

The regional characterization of a previously obtained hamster-sheep hybrid panel is reported. Using data available from ruminant maps (sheep, cattle, and goat), we have selected a set of 300 markers and have analyzed them by PCR in this hybrid panel. Results obtained for 204 markers show the presence of all sheep chromosomes (including gonosomes) in entire or fragmented form. Analysis of syntenies has given 130 types of answer defining segments of variable sizes. This study has led to the regional characterization of this panel and provides comparative data on a set of bovine and caprine markers. With the level of characterization now achieved for this hybrid panel, the regional assignment of new genes or markers to sheep chromosomes can be rapidly obtained. Finally, this panel will help to collect new data for comparative mapping of domestic animals and to highlight the conservation of syntenic groups between closely related species, that is, sheep, cattle, and goat.

The genetic and cytogenetic map around the chromosome 1 region shown to be linked with polledness and intersexuality (PIS) in the domestic goat (Capra hircus) was refined. For this purpose, a goat BAC library was systematically screened with primers from human coding sequences, scraped chromosome 1 DNA, bovine microsatellites from the region, and BAC ends. All the BACs (n = 30) were mapped by fluorescence in situ hybridization (FISH) on goat chromosome 1q41-q45. The genetic mapping of 30 new goat polymorphic markers, isolated from these BACs, made it possible to reduce the PIS interval to a region of less than 1 cM on goat chromosome 1q43. The PIS locus is now located between the two genes ATP1B and COP, which both map to 3q23 in humans. Genetic, cytogenetic, and comparative data suggest that the PIS region is now probably circumscribed to an approximately 1-Mb DNA segment for which construction of a BAC contig is in progress. In addition, a human YAC contig encompassing the blepharophimosis-ptosis-epicanthus-inversus region was mapped by FISH to goat chromosome 1q43. This human disease, mapped to HSA 3q23 and affecting the development and maintenance of ovarian function, could be a potential candidate for goat PIS.

The bovine erythrocyte membrane carries Rhesus (Rh)-like proteins. To obtain a bovine nucleotide probe, a cDNA library of foetal liver was constructed and screened with the human RhCE probe. Three clones (245 bp, 1012 bp and 1400 bp) were isolated and sequenced. They share a high degree of similarity (up to 73%) with Rh-like cDNAs of primates characterized so far and all of them were shown to contain a polymorphic microsatellite in their 3' untranslated region. Their sequences support the occurrence of different splicing isoforms transcribed from the same RH-like gene. One of the clones (1400 bp), which has a 134-nucleotide deletion causing a frameshift, is structurally similar to the human Rh4 cDNA isoform. Synteny mapping and genetic linkage analysis located the bovine RH-like locus on chromosome BTA2, on which none of the 10 previously mapped blood group systems are found. In situ hybridization mapped the RH-like locus to BTA2q45. No linkage was detected between the microsatellite and the only unmapped blood group system (locus F). These results strongly suggest that the putative bovine Rh-like polypeptides do not correspond to any previously described bovine blood group. Comparative studies of human and bovine maps clearly show that the human RH locus, which is located on HSA1p34-p36, and its bovine counterpart belong to a linkage group highly conserved between both species.

The SOX gene family consists of a large number of embryonically expressed genes capable of encoding putative transcription factors and related by a DNA-binding domain, the HMG-box. We cloned and characterized the ovine SOX2 transcript using the screening of a testis (12dpp) cDNA library with a probe containing the SRY-HMG-box and we performed 3'RACE experiments. The ovine SOX2 sequence is strongly conserved in comparison to the human, mouse and chicken homologues and is located on sheep chromosome 1q33. The SOX2 expression pattern in developing gonads is consistent with the hypothesis that this gene plays a role in the germ cell line.

A comparative linkage map of human chromosome 13 and bovine chromosome 12 was constructed using eight polymorphic microsatellite markers associated with six specific genes. Linkage of these was also examined relative to five previously mapped anonymous microsatellite markers. Seven gene-linked markers were developed from bovine large-insert genomic clones containing one of five genes of interest (serotonin receptor subtype 2, fms-related tyrosine kinase, coagulation factor 10, retinoblastoma susceptibility gene, collagen type IV alpha 1), and one additional marker was developed from a microsatellite resident within an intron of the bovine dopachrome tautomerase gene. Four of these loci were previously assigned to bovine chromosome 12 by analysis of a somatic cell hybrid panel. This study provides linkage information for examining gene order in this conserved synteny group. The comparative linkage mapping results indicate that the q arm of human chromosome 13 is almost entirely conserved in bovine chromosome 12. One intrachromosomal rearrangement was detected in this linkage group relative to human, and this rearrangement was confirmed by fluorescence in situ hybridization results.

In swine, distinct centromeric satellite DNA families have been described that correspond to either all the meta-centric chromosomes except the Y (Mel) or all the acrocentric chromosomes (Ac2). Using primed in situ (PRINS) labeling, we show here that primers derived from various sequences specifically label the centromeres of different subgroups of chromosomes. Among five primers derived from centromeric sequences of acrocentric chromosomes reported to be very homogeneous, four recognize all the acrocentric chromosomes, whereas one labels prominently chromosome 17. For the metacentric chromosomes, six primers have been derived from several divergent sequences. Among these primers, two recognize all the metacentric chromosomes except 5, 10, and 12. Three other primers label small subsets of metacentric chromosomes, including the X and one or two additional chromosomes. The last primer is specific to chromosome 1. These preliminary results suggest that it should be possible to define specific primers for almost every swine chromosome. Already, some of the primers reported here permit a distinction between swine chromosomes difficult to differentiate without banding, such as the X chromosome and chromosome 9. Therefore, the PRINS technique using centromeric motifs constitutes an additional tool for cytogenetic studies in swine.

International audience; Le décret 2011-1728 rendra obligatoire la surveillance de la qualité de l’air dans les bâtiments publics français en 2015. Afin de mettre en place les modalités de cette surveillance, une campagne pilote a été initiée en 2009 et a consisté à mesurer les concentrations de formaldéhyde, de benzène et le confinement au sein de 300 écoles primaires et crèches. La première phase de cette campagne a révélé quatre salles de classe présentant des concentrations en formaldéhyde proches de la valeur d’information et de recommandation actuelle égale à 50 µg/m3. Le Laboratoire Central de Surveillance de la Qualité de l’Air (LCSQA) a été missionné pour effectuer un diagnostic des sources d’émission de formaldéhyde au sein de ces écoles. Les taux d’émission des matériaux de construction et d’ameublement ont été mesurés sur site avec un préleveur passif développé à l’École des Mines de Douai. Plus de 30 sources d’émission différentes ont été mesurées dans chaque salle de classe, avec des taux d’émission compris entre 8 et 255 µg/m2/h. Le plafond a été identifié comme la source d’émission principale dans chacune des écoles (34 à 70 % des émissions totales). Les taux d’émission mesurés ont ensuite été utilisés pour contraindre un modèle d’équilibre des masses qui a permis de tester l’efficacité de différentes stratégies de réduction des concentrations en formaldéhyde.

The flanking sequences of several genes have been shown to direct a position independent expression of transgenes. Attempts to completely identify the insulating sequences have failed so far. Some of these sequences contain a matrix attached region (MAR) located in the flanking part of the genes. This article will show that the MARs in cultured cells located in the 3' OH region of the human apolipoprotein B100 (Apo B100) and within the SV40 genome were unable to stimulate and insultate transgene expression directed by the promoters from a rabbit whey acidic protein (WAP) gene or from human cytomegalovirus (hCMV) early genes. In transgenic mice, the MAR from the Apo B100 and SV40 genes did not enhance the expression of a transgene containing the rabbit whey acid protein (WAP) promotor, the late gene SV40 intron (VP1 intron), the bovine growth hormone (bGH) cDNA and the SV40 late gene terminator. This construct was even toxic for embryos. Similarly, the specialized chromatin structure (SCS) from the Drosophila 87A7 HSP70 gene reduced chloramphenicol acetyl transferase (CAT) activity when added between a cytomegalovirus (CMV) enhancer and a Herpes simplex thymidine kinase (TK) gene promoter. This inhibitory action was almost complete when a second SCS sequence was added before the CMV enhancer. Sequences from the firefly luciferase and from the human gene cathepsin D cDNA used as control unexpectedly showed a similar inhibitory effect when added to the CMVTKCAT construct instead of SCS. When added before the CMV enhancer and after the transcription terminator in the CMVTKCAT construct, the SCS sequence was unable to insulate the integrated gene as seen by the fact that the level of CAT in cell extracts were by no means correlated with the number of copies in individual clones. From these data, it is concluded that i) a MAR containing the canonical AT rich sequences does not amplify the expression of all gene constructs ii) At rich MAR sequences do not have per se an insulating effect iii) Drosophila SCS from the 87A7 HSP70 gene has no insulating effect in all gene constructs (at least in mammalian cells) iv) and the addition of a DNA fragment between an enhancer and a promoter in a gene construct cannot be used as a reliable test to evaluate its insulating property.

Deux lignées de poules pondeuses ont été sélectionnées sur la consommation alimentaire résiduelle (+ R à consommation élevée, R- à faible consommation). Une détérioration des taux de fertilité et d’éclosion est observée dans la lignée R+. De nombreuses études réalisées sur les mammifères et les oiseaux ont montré l’association entre la mortalité embryonnaire et la présence d’anomalies chromosomiques. Dans le présent travail, des observations phénotypiques et des analyses cytogénétiques - limitées aux 10 premières paires de chromosomes observées et aux chromosomes sexuels, pour un total de 2n = 78 - ont été effectuées sur des embryons âgés de 48 ou de 16-18 h issus des 2 lignées R- et R+ aux générations 14 et 15. Des prélèvements de pulpes de plumes ont aussi permis de déterminer le caryotype de quelques adultes reproducteurs issus des 2 lignées. Le pourcentage d’oeufs clairs (non fécondés) est toujours significativement plus élevé en lignée R+. Les quelques cas d’anomalies chromosomiques mises en évidence dans les 2 lignées ne semblent pas être à l’origine de la baisse de fertilité de la lignée R+. Les reproducteurs adultes étudiés avaient tous des caryotypes normaux. L’explication de la baisse de fertilité en lignée R+ s’orienterait plutôt vers un problème de qualité des spermatozoïdes ou de leur conservation dans les voies génitales femelles dans la mesure ou l’étude cytogénétique n’a montré aucune anomalie de la méiose femelle ou de la multiplication des cellules embryonnaires. De plus les difficultés de reproduction ne sont pas concentrées dans certaines familles mais retrouvées dans toute la lignée., Two lines of brown egg layers have been divergently selected on residual food consumption (RFC). They differ markedly in their reproductive performance which deteriorates in the line selected on high values of RFC (R+ line). Several studies carried out in mammals and birds have shown a clear association between embryonic mortality and chromosomal abnormalities. In this study, fertile eggs were sampled from both lines at generations 14 and 15 after 48 or 16-18 h of incubation in order to observe the embryo development and determine the karyotype, on the first 10 pairs of chromosomes observed and sexual chromosomes, out of a total 2n = 78. Karyotypes were also prepared from feather pulps of adult breeders. The percentage of unfertilized eggs was always significantly higher in the R+ line. The few chromosomal abnormalities observed in both lines could not be responsible for the reduction in fertility in the R+ line. The adult karyotypes were normal. The lower fertility in the R+ line probably involves the quality of sperm cells or their conservation in the female genital tract, since cytogenetic analysis did not show any specific abnormality in female meiosis or in embryo cell multiplication. Furthermore, fertility problems were not clustered in some families but distributed over the entire line.

A bovine bivariate flow karyotype has been established from a primary fibroblast cell culture carrying a 4;10 Robertsonian translocation. From 27 to 36 populations could be resolved by flow cytometry although the anticipated number was 31. Separation of chromosomal pairs into two populations explains this high resolution and confirms the high level of heteromorphism previously observed. We used a PARM-PCR (Priming Authorizing Random Mismatches) procedure for the production of paint probes from flow-sorted chromosome fractions. These probes were used for chromosome identification by fluorescence in situ hybridization (FISH) on R-banded metaphase spreads. We present the localization of all the bovine chromosome types on the flow karyotype. Twenty-two chromosome types including the translocated chromosome were sorted as pure fractions.

The chromosomes of nine gazelle species and two other Antilopinae species (Antidorcas marsupialis and Antilope cervicapra) were prepared from fibroblast cultures. G- and C-band karyotypes were constructed, and when possible, autosomal arms were numbered according to the cattle standard karyotype. Diploid chromosome numbers ranged from 30 to 58. Based on band similarity, chromosome-arm homoeologies were extensive, whereas shared homoeologous biarmed chromosomes were rare. Therefore evolution in this genus could have occurred mainly by speciation following monobrachial homoeology of centric fusions. X to autosome translocations were common in the whole genus. Furthermore, chromosome Y was also involved in an autosome translocation in gazelles from the subgenus Nanger and in Gazella thomsoni and G. rufifrons. Based on these karyotypic data a phylogenetic tree is proposed. This phylogenetic reconstruction confirms most of the taxonomic relationships obtained by morphological analyses for this group of species. The main novelties are the proximity of G. rufifrons and G. thomsoni and the inclusion of Antilope cervicapra in the gazelle group.