Félix de Paz

The Head and Neck Muscles of the Serval and Tiger: Homologies, Evolution, and Proposal of a Mammalian and a Veterinary Muscle Ontology

Here we describe the head and neck muscles of members of the two extant felid subfamilies (Leptailurus serval: Felinae; Panthera tigris: Pantherinae) and compare these muscles with those of other felids, other carnivorans (e.g., domestic dogs), other eutherian mammals (e.g., rats, tree‐shrews and modern humans), and noneutherian mammals including monotremes. Another major goal of the article is to discuss and help clarify nomenclatural discrepancies found in the Nomina Anatomica Veterinaria and in veterinary atlases and textbooks that use cats and dogs as models to understand the anatomy of domestic mammals and to stress differences with modern humans. We propose a unifying nomenclature that is expanded to all the head and neck muscles and to all mammalian taxa in order to help build veterinary and mammalian muscle ontologies. Our observations and comparisons and the specific use of this nomenclature point out that felids such as tigers and servals and other carnivorans such as dogs have more facial muscle structures related to the mobility of both the auricular and orbital regions than numerous other mammals, including modern humans, which might be the result of an ancient adaptation related to the remarkable predatory capacities of carnivorans. Interestingly, the skeletal differences, mainly concerning the hyoid apparatus, pharynx, and larynx, that are likely associated with the different types of vocalizations seen in the Felinae (mainly purring) and Pantherinae (mainly roaring) are not accompanied by clear differences in the musculature connected to these structures in the feline L. serval and the pantherine P. tigris. Anat Rec, 2012.

Expression of Myosin Heavy Chain Isoforms in the Supraspinatus Muscle of Different Primate Species: Implications for the Study of the Adaptation of Primate Shoulder Muscles to Different Locomotor Modes

The supraspinatus muscle is a key component of the soft tissues of the shoulder. In pronograde primates, its main function, in combination with the other rotator cuff muscles (subscapularis, infraspinatus, and teres minor), is to stabilize the glenohumeral joint, whereas in orthograde primates it functions together with the deltoid, to elevate the upper extremity in the scapular plane. To determine whether these functional differences are also reflected in the molecular biochemistry of the supraspinatus muscles involved in these different locomotor modes, we used real-time polymerase chain reaction (RT-PCR) to analyze the expression of the myosin heavy chain (MHC) isoforms in supraspinatus muscles from modern humans and 12 species of pronograde and orthograde primates. The MHC expression pattern in the supraspinatus muscle of pronograde primates was consistent with its function as a tonic and postural muscle, whereas the MHC expression pattern observed in the supraspinatus muscle of nonhuman orthograde primates was that of a muscle that emphasizes speed, strength, and less resistance to fatigue. These findings are consistent with the role of the supraspinatus in the posture and locomotor modes of these groups of nonhuman primates. The humans included in the study had an expression pattern similar to that of the nonhuman orthograde primates. In conclusion, molecular analysis of skeletal muscles via RT-PCR can contribute to a better understanding of the morphological and functional characteristics of the primate musculoskeletal system.

Biometry and Statistical Analysis of the Styloid Process

The hyoid apparatus is made up of three osteocartilaginous elements that go from the base of the cranium to the hyoid bone; the portions, cranially to caudally, are as follow: stylohyal, ceratohyal, and apohyal. Fusion and ossification of these three components will bring about somewhat long stylohyoid processes, whereas the stylohyal portion is the one that gives rise to the authentic stylohyoid process. The variability of the hyoid apparatus may imply associated compressive pathologies, for which an etiological diagnosis is important. A study was undertaken of 835 craniums of a homogeneous male and female adult population, involving a morphometric analysis of the styloid processes in which quantification was made of the following continual descriptive measurements: thickness, length, sagittal angle, transversal angle, and the distance between vertices. Multivariate data analysis techniques were applied to the data set to describe the relationships between these measurements. The main conclusion from the analysis is the existence of two different groups of styloid processes and the derivation of a prediction score. Anat Rec, 2012.

Introduction, Aims, Methodology and Materials

Strikingly, until the publication of this book comprehensive data about the soft tissues of our closest living relatives, the chimpanzees, was only available for common chimpanzees, as even Miller’s 1952 study of bonobo musculature was incomplete and restricted to a single individual. Few zoos keep bonobos and cadavers are difficult to come by, but thanks to the foresight of researchers at the Antwerp Zoo, which has one of the largest collections of bonobos in captivity, seven bonobo cadavers had been preserved. Thanks also to a collaboration between the Antwerp Zoo and the Applied Veterinary Morphology group of the Department of Veterinary Sciences at the University of Antwerp, arrangements were made for a team of researchers, including the authors of this book, to dissect all seven cadavers, which comprise males and females and fetal, infant, adolescent and adult stages.

Lower Limb Musculature and Lumbosacral Plexus

In this chapter, we describe the lower limb musculature musculature of the bonobos dissected by us and by other previous authors and compare it with that of common chimpanzees. The three major differences between the two chimpanzee species are that bonobos usually retain a scansorius and have popliteus-fibula and extensor hallucis longus-proximal big toe phalanx attachments: all these three features are usually missing in common chimpanzees and humans.

Upper Limb Musculature and Brachial Plexus

In this chapter we describe the upper limb musculature musculature of the bonobos dissected by us and by other previous authors, and compare it with that of common chimpanzees. The three major differences between the two chimpanzee species are: (1) the intermetacarpales and flexores breves profundi muscles in the hand of bonobos usually fuse to form dorsal interossei, a shared feature with modern humans; (2) bonobos usually have a stout tendon of the flexor digitorum profundus attaching to digit 1 (in modern humans the homologous tendon of the flexor pollicis longus to digit 1 is usually also stout; and (3) bonobos usually have an attachment between the pectoralis minor and the coracoid process of the scapula, as modern humans usually do.

Trunk, Diaphragmatic, Perineal and Coccygeal Musculature

In this chapter we describe the trunk, diaphragmatic, perineal and coccygeal musculature of the bonobos dissected by us and by other previous authors, and compare it with that of common chimpanzees. There are no major differences, for instance concerning the consistent presence of certain muscles in one species versus the consistent absence in the other, between the two chimpanzee species.

Head and Neck Musculature

In this chapter we describe the head and neck musculature of the bonobos dissected by us and by other previous authors, and compare it with that of common chimpanzees. The only major difference between the two chimpanzee species is that bonobos usually have a single belly of the omohyoideus, contrary to the two bellies that are usually present in both common chimpanzees and modern humans.

Quantification of Myosin Heavy Chain Isoform mRNA Transcripts in the Supraspinatus Muscle of Vertical Clinger Primates

Vertical clinging is a specialized form of locomotion characteristic of the primate family Callitrichidae. Vertical clinging requires these pronograde primates to maintain a vertical posture, so the protraction of their forelimbs must resist gravity. Since pronograde primates usually move as horizontal quadrupeds, we hypothesized that the supraspinatus muscle of vertical clingers would present specific characteristics related to the functional requirements imposed on the shoulder area by vertical clinging. To test this hypothesis, we quantified by real-time quantitative polymerase chain reaction the mRNA transcripts of myosin heavy chain (MHC) isoforms in the supraspinatus muscle of 15 species of pronograde primates, including vertical clingers. Our results indicate that the supraspinatus of vertical clingers has a specific expression pattern of the MHC isoforms, with a low expression of the transcripts of the slow MHC-I isoform and a high expression of the transcripts of the fast MHC-II isoforms. We conclude that these differences can be related to the particular functional characteristics of the shoulder in vertical clingers, but also to other anatomical adaptations of these primates, such as their small body size.