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The potential of artificial selection to dramatically impact phenotypic diversity is well known. Large-scale morphological changes in domestic species, emerging over short timescales, offer an accelerated perspective on evolutionary processes. The domestic horse (Equus caballus) provides a striking example of rapid evolution, with major changes in morphology and size likely stemming from artificial selection. However, the microevolutionary mechanisms allowing to generate this variation in a short time interval remain little known. Here, we use 3D geometric morphometrics to quantify skull morphological diversity in the horse, and investigate modularity and integration patterns to understand how morphological associations contribute to cranial evolvability in this taxon. We find that changes in the magnitude of cranial integration contribute to the diversification of the skull morphology in horse breeds. Our results demonstrate that a conserved pattern of modularity does not constrain large-scale morphological variations in horses and that artificial selection has impacted mechanisms underlying phenotypic diversity to facilitate rapid shape changes. More broadly, this study demonstrates that studying microevolutionary processes in domestic species produces important insights into extant phenotypic diversity. Introduction Material and methods - Material - Acquisition of data - Shape analyses - Integration and modularity -- Modular patterning -- Covariation patterns -- Magnitude of morphological integration Results - Size and shape variation - Allometry‑free shape variation - Allometry‑free shape variation of the modules - Modularity and integration Discussion - Cranial shape variation in the horse: the role of allometry and artificial selection in the morphological diversification - Cranial modularity and shape diversification -- Stasis in patterns, changes in magnitude -- Influence of morphological integration on shape variance - The role of function and development in integration patterns -- Anterior region -- Posterior region Conclusion

Cette étude a été menée sur des dromadaires vivants algériens Naili encore appelés Chameaux de la steppe. L’objectif était de caractériser les mensurations et la barymétrie de cette population qui n’a pas encore été étudiée et de les comparer à deux autres populations algériennes, la Sahraoui et la Targui. L’échantillon comprenait 60 dromadaires, 30 mâles et 30 femelles adultes de plus de cinq ans qui pâturaient dans les régions semi-arides du nord de Biskra en Algérie. Cinq mensurations ont été faites, puis l’indice (de vide) sous-sternal et le poids vif ont été calculés. Les valeurs moyennes ont été respectivement chez les mâles et chez les femelles de 551,2 kg ± 58,7 kg et 482,6 kg ± 60,0 kg pour le poids vif, de 0,92 m ± 0,05 m et 0,83 m ± 0,08 m pour le vide sous-sternal, de 0,92 m ± 0,05 m et 0,88 m ± 0,04 m pour la profondeur thoracique, et de 1,02 ± 0,09 et 0,94 ± 0,11 pour l’indice sous-sternal. Une analyse multivariée a permis de séparer les mâles des femelles et de les comparer aux populations Sahraoui et Targui. Le Chameau de la steppe se différencie nettement de ces populations par sa plus petite taille. Cette étude montre également que les chamelles sont un peu plus petites et moins élancées que les mâles. Cette population rustique est associée à un ensemble de pratiques alimentaires, elles-mêmes liées à la qualité des parcours dont l’influence sur le développement morphologique des animaux a été largement décrite.

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Dogs are among the most variable species today, but little is known about the morphological variability in the early phases of their history. The Neolithic transition to farming may have resulted in an early morphological diversification as a result of changes in the anthropic environment or intentional selection on specific morphologies. Here, we describe the variability and modularity in mandible form by comparing 525 dog mandibles from European archaeological sites ranging from 8100 to 3000 cal. BC to a reference sample of modern dogs, wolves, and dingoes. We use three-dimensional geometric morphometrics to quantify the form of complete and fragmented mandibles. We demonstrate that an important morphological variability already existed before the Bronze Age in Europe, yet the largest, smallest, most brachycephalic or dolichocephalic extant dogs have no equivalent in the archaeological sample, resulting in a lower variation compared to modern relatives. The covariation between the anterior and posterior parts of the mandible is lower in archaeological dogs, suggesting a low degree of intentional human selection in early periods. The mandible of modern and ancient dogs differs in functionally important areas, possibly reflecting differences in diet, competition, or the implication of ancient dogs in hunting or defence.

Many studies have attested to the consequences of the recent and intense artificial selection on the morphological variability of the cranium and mandible in domestic animals. However, the functional relations of the cranium with other constituents of the masticatory apparatus (the mandibles and the adductor muscles) have rarely been explored. Previous work has demonstrated strong relationships between the overall shape of the mandible and muscle data, however, drastic artificial selection in dogs has led to frequent malocclusions, suggesting a possible decoupling between the cranium and the mandible. Moreover, the more complex role of the cranium suggests that it is likely less impacted by, and correlated with, the architecture of the jaw muscles than the mandible. We explored the covariations between cranial and mandibular shape and between cranial shape and the masticatory muscle architecture. Shape analyses were conducted on 58 dogs from various breeds and we used muscle data previously obtained from the dissection of 48 of these dogs. The shape of the cranium was quantified using 3D geometric morphometric approaches. Principal component analyses (PCA) and two-block partial least square analyses (2B-PLS) were used to quantify the variations in cranial shape and the covariations with mandible shape and muscle architecture, respectively. Interestingly, our results reveal strong covariations between cranial shape and mandibular shape and between cranial shape and masticatory muscles mass or physiological cross-sectional area, irrespective of whether size is taken into account or not. We conclude that the drastic artificial selection in domestic dogs has not tainted the integrity of the jaw system, which reinforces previous assumptions hypothesising that phenotypic variability in dogs may be limited by developmental factors.

Le Scinque officinal ou Poisson de sable Scincus scincus (Linnaeus, 1758) (Scincidae: Squamata) est un lezard qui a une aptitude a se mouvoir dans les sables du desert particulierement remarquable. Il a fait l'objet d'etudes anatomo-fonctionnelles en lien avec sa locomotion originale, ainsi que recemment d'etudes sur sa valeur nutritionnelle comme source de proteines animales, mais a ce jour, aucun travail sur la biometrie ou sur le dimorphisme sexuel de cette espece n'a ete publie. Cette etude de la morphometrie externe de l'animal repose sur 100 individus adultes (50 mâles et 50 femelles) de la sous-espece Scincus scincus scincus (Linnaeus, 1758) recuperes dans la region de El Oued Souf (Algerie) et vise a caracteriser le dimorphisme sexuel de l'espece. En plus du poids vif des individus, 11 parametres lineaires ont ete mesures par animal et 3 indices de forme ont ete calcules. Pour chaque variable, une valeur seuil permettant de discriminer au mieux les mâles des femelles est proposee. Le modele lineaire generalise multivarie le plus discriminant integre CT (le perimetre thoracique), T (la longueur de la tete) et LmP (la longueur du membre pelvien). Cependant, la mesure T, consideree seule, discrimine avec un faible taux d'erreur.

The jaw system in canids is essential for defence and prey acquisition. However, how it varies in wild species in comparison with domestic species remains poorly understood, yet is of interest in terms of understanding the impact of artificial selection. Here, we explored the variability and interrelationships between the upper and lower jaws, muscle architecture and bite force in the red fox (Vulpes vulpes). We performed dissections and used 3D geometric morphometric approaches to quantify jaw shape in 68 foxes. We used a static lever model and bite force estimates were compared with in vivo measurements of 10 silver foxes. Our results show strong relationships exist between cranial and mandible shape, and between cranial or mandible shape on the one hand and muscles or estimated bite force on the other hand, confirming the strong integration of the bony and muscular components of the jaw system. These strong relationships are strongly driven by size. The functional links between shape and estimated bite force are stronger for the mandible, which probably reflects its greater specialisation towards biting. We then compared our results with data previously obtained for dogs (Canis lupus familiaris) to investigate the effect of domestication. Foxes and dogs differ in skull shape and muscle physiological cross-sectional area (PCSA). They show a similar amount of morphological variation in muscle PCSA, but foxes show lower variation in cranial and mandible shape. Interestingly, the patterns of covariation are not stronger in foxes than in dogs, suggesting that domestication did not lead to a disruption of the functional links of the jaw system.

In the course of evolution, pecorans (i.e., higher ruminants) developed a remarkable diversity of osseous cranial appendages, collectively referred to as “headgear,” which likely share the same origin and genetic basis. However, the nature and function of the genetic determinants underlying their number and position remain elusive. Jacob and other rare populations of sheep and goats are characterized by polyceraty, the presence of more than two horns. Here, we characterize distinct POLYCERATE alleles in each species, both associated with defective HOXD1 function. We show that haploinsufficiency at this locus results in the splitting of horn bud primordia, likely following the abnormal extension of an initial morphogenetic field. These results highlight the key role played by this gene in headgear patterning and illustrate the evolutionary co-option of a gene involved in the early development of bilateria to properly fix the position and number of these distinctive organs of Bovidae.

In the course of evolution, pecorans (i.e. higher ruminants) developed a remarkable diversity of osseous cranial appendages, collectively referred to as ‘headgear’, which likely share the same origin and genetic basis. However, the nature and function of the genetic determinants underlying their number and position remain elusive. Jacob and other rare populations of sheep and goats, are characterized by polyceraty, the presence of more than two horns. Here, we characterize distinct POLYCERATE alleles in each species, both associated with defective HOXD1 function. We show that haploinsufficiency at this locus results in the splitting of horn bud primordia, likely following the abnormal extension of an initial morphogenetic field. These results highlight the key role played by this gene in headgear patterning and illustrate the evolutionary co-option of a gene involved in the early development of bilateria to properly fix the position and number of these distinctive organs of Bovidae.

The Merovingian period sees the emergence of the saddle horse as a critical component of the military forces. This increased importance is generally thought to be associated with a particular attention paid to horse breeding, which contributed to preserve the large size they acquired during Roman period. In spite of the Early Middle Ages being considered as a turning point in the history of their usage in Western Europe, its impact on the morphological traits of the horses remain largely unexplored. Privilege of the warrior elite, the horse is also a marker of social rank when associated to human burials. The royal tomb of Childeric the 1st (Tournai, Belgium), considered as the most lavish of the western Germanic world, revealed the presence of twenty-one skeletons of equids, deposited in peripheral pits. Here we use 3D geometric morphometrics to characterize the morphological traits and possible function of these equids using shape variation and covariation analyses of the limb bones. We found close phenotypic proximities with modern racehorse specimens. However, differences in magnitude of morphological integration between them suggest specificities in the functional features of the archaeological horses and probably reflect variation in the degree of artificial selection. Our results demonstrate the importance of accurately exploring the complete shape of bones to describe the morphological characteristics of past animals. Our results also illustrate the interest of not only investigating shape variation, but also covariation patterns, in order to address functional questions and in trying to detect possible markers of artificial selection on past horses.

Previous studies based on two-dimensional methods have suggested that the great morphological variability of cranial shape in domestic dogs has impacted bite performance. Here we use a three-dimensional biomechanical model based on dissection data to estimate the bite force of 47 dogs of various breeds at several bite points and gape angles. In vivo bite forces for three Belgian Shepherd dogs were used to validate our model. We then used three-dimensional geometric morphometrics to investigate the drivers of bite force variation and to describe the relations between the overall shape of the jaws and bite force. The model output shows that bite force is rather variable in dogs and that dogs bite harder on the molar teeth and at lower gape angles. Half of the bite force is determined by the temporal muscle. Bite force also increased with size, and brachycephalic dogs showed higher bite forces for their size than mesocephalic dogs. We obtained significant covariations between the shape of the upper or lower jaw and absolute or scaled bite force. Our results demonstrate that domestication has not resulted in a disruption of the functional links in the jaw system in dogs and that mandible shape is a good predictor of bite force.

Despite the considerable scientific interest in the variability and patterns of integration in the dog skull, how these patterns impact or are driven by function remains largely unexplored. Since the mandible is directly involved in mastication, it can be expected to be directly related to the development of the adductor and abductor muscles. Here, we explore whether variation in the architecture and size of the masticatory muscles is associated with the variation in mandibular shape in dogs. We obtained muscle data from the dissection of 48 dogs from different breeds and morphotypes to explore the architecture of the muscles and used 3D geometric morphometric approaches to quantify the shape of the mandible. Covariations between the masticatory muscles and mandibular shape were explored using two-block partial least square analyses (2B-PLS). Our results show there is a strong covariation between mandibular shape and masticatory muscles mass (rPLS from 0.70 to 0.74 for the first axis representing more than 90% of the total covariance) and physiological cross-sectional area (rPLS from 0.64 to 0.73 for the first axis representing more than 80% of the total covariance), irrespective of whether size is taken into account or not. These results suggest muscle size and thus attachment area requirements for individual muscles are likely drivers of mandibular shape. Moreover, mandible shape is likely to be a good predictor of muscle force. Finally, it appears that domestication of dogs has not resulted in a disuse phenotype characterized by a decoupling between form and function.

International audience; Archaeozoology provides bones, which quite regularly present traces of fractures. These fractures are more orless at an advanced level of healing and bear witness to traumas or pathologies. These cases of palaeopathologyare not always the subject of publications, which further restricts our knowledge about them. This short noteallows the scientific community to be aware of an original case from an archaeological context in Jordan of afracture on a hen’s femur, consolidated by a callus and with displacement of the distal ends. Beyond the "anecdotal"aspect, and without imagining the circumstances in which the fracture occurred, the animal survived.

L’objectif de cette étude était de comparer les caractérisations morphologiques et de déterminer l’indice de gracilité d’après des mesures zoométriques sur des chamelles adultes de deux populations algériennes, la Sahraoui et la Targui. Les mesures ont été réalisées sur des dromadaires femelles – 30 Sahraoui et 30 Targui – de plus de cinq ans dans le Sahara septentrional (région de Ouargla). Quatre mensurations ont été faites, puis l’indice de gracilité et le poids vif ont été calculés. Des équations de régression linéaire ont été proposées afin d’esti­mer le poids vif des animaux et la hauteur au garrot à partir des mensurations corrélées. Les valeurs moyennes des poids vifs des Sahraoui et des Targui étaient respectivement de 399 ± 74 kg et de 428 ± 82 kg, pour une hauteur au garrot de 1,75 ± 0,08 m et de 1,81 ± 0,08 m. Elles étaient respectivement de 0,96 ± 0,05 m et 0,97 ± 0,08 m pour le vide sous-sternal, de 0,80 ± 0,08 et 0,84 ± 0,07 pour la profondeur thoracique, et de 1,20 ± 0,13 m et 1,18 ± 0,16 m pour l’indice de gracilité sous-sternal. Cette étude montre que la chamelle Tar­gui est un peu plus gracile que la chamelle Sahraoui. Ces populations sont éga­lement associées à un ensemble de pratiques alimentaires, elles-mêmes liées à la qualité des parcours dont l’influence sur le développement morphologique des animaux a été largement observée.

Problématique Un ossement découpé, trouvé dans un horizon archéologique pertinent, est une source d’informations majeures sur certaines pratiques anthropiques. Si un reste osseux va classiquement renseigner le choix d’une partie anatomique et celui d’une espèce, la découpe va, quant à elle, renvoyer à la transformation d’un être vivant en différentes matières façonnables et/ou consommables. L’abattage de l’animal et sa transformation en viandes, au gré des outils et des schémas de découpes, s...

Paleopathological information observed in cats (Felis catus, L. 1758) is rarely described in zooarcheological assemblages. This article is intended to present different bone diseases (infections, degenerative and traumatic lesions) affecting several bones (i.e. femur, hip bone, skull, etc.) of at least two cats from the medieval harbor site of Qalhât (Oman) and to inform us about the health status of these felines.

The first evidence for the domestication of donkeys (Equus asinus) dates back to at least 6000-5000 BP in Northeast Africa, and their dispersion is attributed to the ancient Romans. Latin authors described donkeys as being particularly suitable for the transport of goods and farm work. In addition, they were also bred to produce prized hybrids, particularly mules, which were perfectly adapted to the long-distance transport of people and goods. However, although the historical sources extensively describe their economic importance, both donkey and hybrid remains are surprisingly scarce in the archaeological record. This apparent contradiction is probably due to the difficulties involved in correctly identifying their bones: relatively few bones displaying morphological and metrical criteria can be used for identification, so it is often based purely on bone size. The aim of this study, therefore, is to propose solutions to identify domestic equid bones using 3D geometric morphometrics on isolated and combinations of anatomical elements. A set of 3D coordinates were registered on the 18 main skull and limb bones of 111 modern reference specimens (i.e. 42 horses, 44 donkeys and 25 hybrids). In this paper, we present the classification rate obtained on this reference sample using the k-Nearest Neighbors algorithm. The application of this method on archaeological skeletons from Roman to modern sites is also presented. The percentage of correctly classified specimens was between 77% and 95% for all 18 bones, and higher than 80% for 10 of the fragmentation patterns we defined. Using a combination of several bones enabled us to increase the rate of correct reclassification to a maximum of 97%. The application to archaeological skeletons proved the ability of this method to identify domestic horses and donkeys from archaeological samples. Correspondingly, some bones, and especially combinations of bones, provided good rates to identify hybrids. This method has proved reliable in detecting the presence of donkeys and hybrids from the archaeological samples of equid bones, and should enrich our knowledge regarding their spread across Europe.

Hypertype in the canine species has been subject to a lot of thoughts and many publications but the novelty of this work is that it associates two complementary points of view, namely the breeder’s and judge’s andvon the other hand the anatomist’s and vet’s. If at shows, the worship of beauty, driven to exaggeration, has taken the step on fitness, one can wonder which tools would be able to avoid these phenomena that are detrimental to the well-being, indeed the soundness of the dogs produced. The standard lever is often put forward ; however, one can wonder whether it is not the interpretation of it (or sometimes the lack of meticulous reading) more than the standards themselves which is the cause of these phenomena. The writing of the current standards, according to the FCI template, should not be able to lead to hypertypes, it is all about valuation and balance from the various players of the dog world. Tools other than standards are clearly available to fight against hypertypes, the authors will only enounce them without developing., L’hypertype dans l’espèce canine a fait l’objet de nombreuses réflexions et publications mais l’originalité de ce travail réside dans le fait qu’il associe deux visions complémentaires, à savoir celle du juge et de l’éleveur d’un côté et celle de l’anatomiste et du vétérinaire de l’autre. Si en exposition canine, le culte du beau, poussé à l’exagération, pourrait prendre le pas sur la fonctionnalité ; on peut se demander quels sont les outils qui permettent d’éviter ces phénomènes préjudiciables pour le bien-être, voire la santé des chiens produits. Le levier du standard est souvent mis en avant, on peut toutefois se demander si ce n’est pas l’interprétation qui en est faite (voire la non lecture minutieuse des standards parfois) plus que les standards eux-mêmes qui est à l’origine de ce phénomène. La rédaction des standards actuels, selon le modèle de la Fédération Cynologique Internationale (FCI), ne devrait pas pouvoir aboutir à des hypertypes ; tout est question d’appréciation et d’équilibre de la part des différents acteurs de la cynophilie. D’autres outils que les standards sont clairement utilisables pour combattre les hypertypes, les auteurs ne feront que les énoncer, sans les développer., Guintard Claude, Class Anne-Marie. Hypertypes et standards de races chez le chien : une histoire d’équilibre. In: Bulletin de l'Académie Vétérinaire de France tome 170 n°5, 2017. pp. 231-249.

BackgroundHybridization has been widely practiced in plant and animal breeding as a means to enhance the quality and fitness of the organisms. In domestic equids, this hybrid vigor takes the form of improved physical and physiological characteristics, notably for strength or endurance. Because the offspring of horse and donkey is generally sterile, this widely recognized vigor is expressed in the first generation (F1). However, in the absence of recombination between the two parental genomes, F1 hybrids can be expected to be phenotypically intermediate between their parents which could potentially restrict the possibilities of an increase in overall fitness. In this study, we examine the morphology of the main limb bones of domestic horses, donkeys and their hybrids to investigate the phenotypic impact of hybridization on the locomotor system. We explore bone shape variation and covariation to gain insights into the morphological and functional expressions of the hybrid vigor commonly described in domestic equids.ResultsOur data reveal the occurrence of transgressive effects on several bones in the F1 generation. The patterns of morphological integration further demonstrate that the developmental processes producing covariation are not disrupted by hybridization, contrary to functional ones.ConclusionsThese results suggest that an increase in overall fitness could be related to more flexibility in shape change in hybrids, except for the main forelimb long bones of which the morphology is strongly driven by muscle interactions. More broadly, this study illustrates the interest of investigating not only bone shape variation but also underlying processes, in order to contribute to better understanding how developmental and functional mechanisms are affected by hybridization.

Objective To describe a contrast medium distribution pattern after peribulbar injection in cadavers. Study design A cadaveric study. Animals A group of eight male dogs and four canine cadaver heads. Methods In phase 1, ultrasound-guided peribulbar injections (1.0 mL dye) were performed in four orbits using a subzygomatic approach. After dissection, the procedure was considered successful if 1) no dye was found in the retrobulbar space, 2) the peribulbar compartment was stained and 3) the dye reached the orbital fissure. In phase 2, using 16 orbits, the same technique was used to inject 0.1 mL kg–1 contrast medium into (group A, n = 8) or outside (group B, n = 8) the peribulbar compartment. After freezing at –20°C, orbits were imaged using computed tomography, and the contrast medium distribution was analysed. Results In phase 1, the procedure was successful in all four eyes. In phase 2, two orbits (one in each group) were removed from the study: one was not injected and the other was injected twice. The contrast medium was found inside the peribulbar compartment in six of seven (85.7%) group A orbits and two of seven (28.6%) group B orbits. In all of these cases, distribution to the orbital fissure, rostral alar foramen, mandibular foramen and inside the skull was observed. The oval foramen was reached in three of seven (42.9%) group A orbits and one of seven (14.3%) group B orbits. In one/seven (14.3%) group A orbits and five/seven (71.4%) group B orbits, the contrast medium was found inside the masseter and temporal muscles, and no distribution towards the aforementioned structures was observed. Conclusions and clinical relevance Ultrasound-guided peribulbar injection of 0.1 mL kg–1 contrast medium in canine cadavers can lead to an extensive distribution of the injectate that reaches the orbital fissure, the rostral alar, oval, and mandibular foramina and can be found intra-cranially.

The relationships between the different component parts of organisms, such as the sharing of common development or function, produce a coordinated variation between the different traits. This morphological integration contributes to drive or constrain morphological variation and thus impacts phenotypic diversification. Artificial selection is known to contribute significantly to phenotypic diversification of domestic species. However, little attention has been paid to its potential impact on integration patterns. This study explores the patterns of integration in the limb bones of different horse breeds, using 3D geometric morphometrics. The domestic horse is known to have been strongly impacted by artificial selection, and was often selected for functional traits. Our results confirm that morphological integration among bones within the same limb is strong and apparently partly produced by functional factors. Most importantly, they reveal that artificial selection, which led to the diversification of domestic horses, impacts covariation patterns. The influence of selection on the patterns of covariation varies along the limbs and modulates bone shape, likely due to a differential ligament or muscle development. These results highlight that, in addition to not being constrained by a strong morphological integration, artificial selection has modulated the covariation patterns according to the locomotor specificities of the breeds. More broadly, it illustrates the interest in studying how micro-evolutionary processes impact covariation patterns and consequently contribute to morphological diversification of domestic species.

International audience; Magnetic resonance imaging (MRI) and computed tomography (CT) scans were used to analyse, respectively, the soft tissues and the bones of the heads of four common dolphins and three harbour porpoises. This imaging study was completed by an examination of anatomical sections performed on two odontocete heads (a subadult common dolphin and a subadult harbour porpoise). The three complementary approaches allowed to illustrate anatomical differences in the echolocation systems of the common dolphin and the harbour porpoise. We captured images confirming strong differences of symmetry of the melon and of its connexions to the MLDB (Monkeys Lips/Dorsal Bursae) between the common dolphin and the harbour porpoise. The melon of the common dolphin is asymmetrically directly connected to the right bursae cantantes at its right side, whereas the melon of the harbour porpoise is symmetrical, and separated from the two bursae cantantes by a set of connective tissues. Another striking difference comes from the bursae cantantes themselves, less deeply located in the head of the common dolphin than in the harbour porpoise.

Dysfunction of venous valves can lead to hemodynamic disorders causing venous stasis, which would favour the occurrence of equine laminitis. However, very few studies have investigated venous valves in the horse digit. The purpose of this study was to compare valvular density between thoracic and pelvic limbs and to study the relationship between valvular density of veins and their location, diameter and wall thickness. After dissection, valvular density was calculated based on the number of valves counted in the principal veins of 7 thoracic and 7 pelvic limbs from 7 horses. Our results showed that the valvular density was higher in thoracic limbs, which probably reflects the adaptation to the consequences of hydrostatic pressure. The superficial veins have a higher valvular density that would prevent the varicose risk in the horse. The lower valvular density in the thick veins can be explained by the high density of the smooth muscular cells contained, which would cause an important vasoconstriction via the sympathetic nervous system. The veins with a large diameter also have a lower valvular density; these veins are not exposed to important changes in hydrostatic pressure. Other valvular characteristics may also be involved in the vascular disorders that may be related to the pathophysiology of laminitis.

Organisms are organized into suites of anatomical structures that typically covary when developmentally or functionally related, and this morphological integration plays a determinant role in evolutionary processes. Artificial selection on domestic species causes strong morphological changes over short time spans, frequently resulting in a wide and exaggerated phenotypic diversity. This raises the question of whether integration constrains the morphological diversification of domestic species and how natural and artificial selection may impact integration patterns. Here, we study the morphological integration in the appendicular skeleton of domestic horses and donkeys, using three-dimensional geometric morphometrics on 75 skeletons. Our results indicate that a strong integration is inherited from developmental mechanisms which interact with functional factors. This strong integration reveals a specialization in the locomotion of domestic equids, partly for running abilities. We show that the integration is stronger in horses than in donkeys, probably because of a greater degree of specialization and predictability of their locomotion. Thus, the constraints imposed by integration are weak enough to allow important morphological changes and the phenotypic diversification of domestic species.

Muscle and bone masses are highly correlated and muscles impose large loads on bone. Muscle wasting that accompanies bone loss has been poorly investigated. 21 female mice were spread into seven groups. At day 0, 18 mice received Botulinum toxin (BTX) injection in the quadriceps muscle to induce paralysis of the right hind limb; the left contralateral side was used as control. Mice were sacrificed at 7, 14, 21, 28, 56 and 90 days post-injection. A remaining group was sacrificed at day 0. Trabecular bone volume was determined by microcomputed tomography (microCT) at the distal femur and tibia proximal metaphyses on both sides. Limbs were immersed in an HgCl2 solution allowing muscle visualization by microCT. On 2D sections, the cross-sectional areas and form-factors were measured for the quadriceps at mid-thigh and gastrocnemius at mid-leg and these muscles were dissected and weighed. Bone volume decreased in the paralysed side. Bone loss was maximal at 56 days followed by recuperation at 90 days. The cross-sectional areas of gastrocnemius and quadriceps were significantly lower in the paralysed limb from 7 days; the decrease was maximum at 21 days for the gastrocnemius and 28 days for the quadriceps. No difference in form-factors was found between the two limbs. Similar results were obtained with the anatomical method and significant correlations were obtained between the two methods. Quantitative analysis of muscle loss and recovery was possible by microCT after using a metallic contrast agent. Loss of bone secondary to muscle wastage induced by BTX and recovery showed a parallel evolution for bone and muscles.

International audience

The anatomy of the gas bladder of Diodontidae (porcupinefishes) and Tetraodontidae (pufferfishes) was studied on the basis of dissections and magnetic resonance imaging. Among the examined taxa of Tetraodontiformes, only puffers and porcupinefishes possess a thick walled and dorsally U-shaped or crescent-moon-shaped gas bladder. In the tetraodontid genus Lagocephalus the gas bladder is reduced to a rudiment. The species belonging to the genera Canthigaster, Arothron, and some species of Tetraodon differ in the positioning of their crescent-moon-shaped gas bladder. These observations confirm the close relationship of: (i) Diodontidae and Tetraodontidae and (ii) Canthigaster, Arothron, and some species of Tetraodon. The heterogeneity of the genus Tetraodon is supported by the gas bladder morphology, as previously suggested by molecular studies.

Twenty bitches were seen in consultation at the Department of Reproduction at ONIRIS (College of Veterinary Medicine, Food Science and Engineering, Loire Atlantique, Nantes, France) between 25 and 50 days of gestation for early sex determination of the canine foetus using ultrasound. The genital tubercle is not visible before 26 days; between 26 and 30 days, it is visible between the pelvic limbs; between 33 and 50 days, the position of the genital tubercle enables sex determination as it migrates caudally in the female and cranially in the male. Good statistical concordance between sexing via ultrasound and sexing at birth has been established (kappa coefficient of 0.8). Macroscopic, microscopic, and histological examinations of the external genital organs were also performed on 10 foetuses at 35 days of gestation; a cartilaginous structure was visualized in the genital apparatus of the male but also in half of the females. Finally, the development of a PCR technique on the SRY gene using formaldehyde-preserved tissues has been described for the first time in this study. It served as a reference for sexing canine foetuses.

Tractor, a 14-year-old Argentinean polo pony mare, aborted at the end of the 2nd trimester of gestation. Incision of the placenta revealed obvious dilatation of the urachus. The umbilical cord was twisted at several locations. There was a deficit in the abdominal wall and the fetal viscera were in contact with the dilatation. The fetus presented complete scoliosis at 90°. Torsion of the umbilical cord, through more than one turn, was evident around the fetlock of the left forelimb.

Magnetic Resonance Imaging (MRI) examinations have been conducted both on fresh and alcohol-preserved common carps (Cyprinus carpio). The images have been compared to those of a sagittally-cut frozen animal of the same species. This work shows that the images obtained are globally similar, and that the MRI technique can be applied to investigate the gross anatomy of alcohol-preserved specimens without destroying them. Unfortunately, this kind of study does not provide precise enough anatomical data for small specimens (less than 10 cm in total length) with a 1 Tesla magnetic field. Nevertheless, leaving the specimen in the jar during MRI examinations does not affect the quality of the final images.

Objectif L’immobilisation a long terme ou une exposition prolongee a la microgravite induisent une atrophie musculaire et une perte osseuse severe. La fonte musculaire qui accompagne la perte osseuse a ete peu etudiee principalement de par l’absence de methode d’analyse appropriee. L’objectif de l’etude est d’evaluer la fonte musculaire dans un modele d’immobilisation chez la souris en utilisant un agent de contraste specifique pour une analyse en microCT. Materiel et methodes 18 souris ont recu une injection de toxine botulique (BTX) dans le quadriceps pour induire une paralysie du membre posterieur droit ; le cote gauche correspond au temoin. Les souris ont ete sacrifiees a 7, 14, 21, 28, 56 et 90 jours post-BTX (3 souris/groupe). 56 et 90 jours correspondent a la recuperation de la mobilite. 3 souris ont ete sacrifiees a j0. Les membres posterieurs ont ete immerges dans une solution de chlorure de mercure (HgCl2) pour la visualisation 3D des muscles par microCT et une analyse morphometrique. Trois parametres ont ete calcules pour 3 muscles d’interet (le quadriceps femoral, le gastrocnemien et le plantaire) : l’aire (mm2) occupee par chaque muscle dans la section 2D, la circularite et l’aspect ratio. Le gastrocnemien et le quadriceps femoral ont ete disseques et peses. Resultats L’aire dans les membres paralyses est reduite des le 7e jour pour le gastrocnemien et le quadriceps. L’aire est minimale au 21e jour pour le quadriceps (–46,9 %) et au 28e jour pour le gastrocnemien (–47,9 %). Aucune difference dans les parametres geometriques de forme n’a ete trouvee. Aucune modification n’a ete observee pour le muscle plantaire. Des correlations significatives ont ete obtenues entre l’aire et le poids pour le gastrocnemien et le quadriceps. Conclusion L’utilisation d’un agent de contraste specifique ouvre de nouvelles perspectives pour mieux comprendre les relations musculosquelettiques.

This study, based on a sample of 215 individuals, gives detailed insight into Sheep metapodial bone main features: their variability and correlations between their various parts. This data allowed us to reveal the most relevant measurements for study of metapodial bones in sheep (GL, Bp, Dp, SD, DD, Bd, and Dd), as well as references used to split up the main population. Those references give a great help in placing any sample in relation to the breeds described in this work. The main purpose of this tool is to compare unknown populations, such as fossil ones, to present sheep breeds, in order to increase our knowledge of domesticated Sheep History, from its origins to the present day.

Magnetic resonance imaging (MRI) examinations for anatomical studies on collection specimens are becoming more and more frequent. As the presence of metallic objects within the specimens can disturb the acquisition of images and damage both specimens and materials, a simple protocol using radiographs is here proposed to detect these objects in collection specimens before conducting an MRI examination.

The anatomy of the gas bladder of Diodontidae (porcupinefishes) and Tetraodontidae (pufferfishes) was studied on the basis of dissections and magnetic resonance imaging. Among the examined taxa of Tetraodontiformes, only puffers and porcupinefishes possess a thick walled and dorsally U-shaped or crescent-moon-shaped gas bladder. In the tetraodontid genus Lagocephalus the gas bladder is reduced to a rudiment. The species belonging to the genera Canthigaster, Arothron, and some species of Tetraodon differ in the positioning of their crescent-moon-shaped gas bladder. These observations confirm the close relationship of: (i) Diodontidae and Tetraodontidae and (ii) Canthigaster, Arothron, and some species of Tetraodon. The heterogeneity of the genus Tetraodon is supported by the gas bladder morphology, as previously suggested by molecular studies.