Anatomical Record-Advances in Integrative Anatomy and Evolutionary Biology最新文献

The individual Geoffroy's side-necked turtle, Phrynops cf. P. geoffroanus, was diagnosed postmortem with osteosarcoma associated with the forelimb through morphological and histological analysis. Osteosarcoma stands as the most prevalent primary malignant bone tumor in tetrapods. The tumor presents itself as a large mass in the distal epiphysis, characterized by spicular outgrowths and a rugose external texture. Histologically, the afflicted humerus displayed a high degree of vascularity and exhibited an extensive bone resorption process involving the medullary and endosteal regions. Notably, a clear transition between the bone marrow and cortical bone was absent, indicative of a remodeling process featuring Haversian bone system apposition. Additionally, the diaphyseal region displayed the progression of neoplastic bone tissue along the bone. For comparative purposes, we describe a humeral thin section from a healthy specimen revealing compact primary bone interrupted by cyclical growth marks which differs from the continuous growth observed in the neoplastic humerus. To assess the neoplastic bone growth rate at the mid-diaphysis level, phylogenetic eigenvector maps (PEM) were employed, utilizing osteocyte density and vascular density as explanatory variables. The findings indicated that the osteosarcoma exhibited a slow-growing nature, suggesting that the turtle had to live with this condition for years. As the neoplasia continued to expand, it likely led to disadvantages for the pathological Phrynops individual due to humeral deformity. Furthermore, malignancy was associated with angiogenesis and the invasion of the medullary region by neoplastic bone tissue, raising the likelihood of metastasis as an additional factor contributing to the individual's sickness. The presence of numerous vascular canals in the diaphyseal thin section suggested a low-grade central osteosarcoma. It is worth noting that osseous neoplasms are rarely documented in Testudines, making this case of osteosarcoma in a South American freshwater chelid specimen a unique and rare occurrence.

Hyperostosis frontalis interna (HFI) is a human skeletal lesion characterized by nodules of hyperplastic bone and thickening of the frontal bone's inner surface. Despite its prevalence in the general population and its long history of observation—it is one of the most frequently observed pathologies in gross anatomy laboratories—HFI's etiology and pathogenesis remain poorly understood. This is largely due to the lack of a thorough survey of its histology across the various stages of its development. Our study has three major aims: (1) assess HFI histology from incipient to advanced lesions; (2) elucidate lamellar and trabecular structure in HFI; and (3) clarify impacts/roles of the dura mater in HFI. Sections of nondecalcified bone provide evidence for two different categories of lesions: (1) stratum lesions, characterized by lamellar-based overall thickening of the internal table, and (2) eruptive lesions, characterized by nodular formations of initially lamellar bone that appear to form the bulk of bone mass in advanced stages. Sections of nondecalcified bone also suggest that for both lesion types, HFI growths begin as deposits of lamellar bone, which are later remodeled into woven bone deposits; our data do not support the hypothesis that lesions begin as a “diploization” of cortical bone as suggested by prior studies. Trichrome-stained sections provide evidence that growing lesions erode through and engulf the dura mater, effectively destroying this tissue layer as they grow laterally and inwardly. Our results indicate possible avenues of research to better understand the root causes of this disorder.

Accipitriformes are diverse in their prey preferences and use their grasping feet for hunting. Little is known about the architectural design of muscles related to grasping among species of different sizes, diets, and foraging behaviors. In the present study, we report quantitative data and analysis of the pelvic musculature of the Japanese sparrowhawk (Accipiter gularis), Eurasian sparrowhawk (Accipiter nisus), common buzzard (Buteo buteo), northern goshawk (Accipiter gentilis), and cinereous vulture (Aegypius monachus). As expected, mass and architecture of the considered muscles were very different between the cinereous vulture and the four other species. The cinereous vulture allocates more mass and physiological cross-sectional area (PCSA) to the proximally inserted flexor muscles, which indicates the rudimentary grasping ability of the foot and is a myological reflection of its carrion preference. Furthermore, in the cinereous vulture, muscles were built with the lowest architectural index (AI) compared with the other species, and the intrinsic foot muscles were short-fibered, which is disadvantageous for rapid manipulation and foot dexterity. The other four species, as a whole, featured large flexor hallucis longus (FHL) muscles and better development of distally inserted flexors, reflecting their predatory lifestyle. Some differences were also found between the species that consumed birds and those that consumed mammals. The two avivorous species were superior in AI and fiber length of the intrinsic foot muscles which are suitable for good hunting speed and digit flexibility, the prerequisition for hunting agile prey.

Previous studies on anuran anomalies predominantly examine isolated cases or focus on external and skeletal features. Our study analyzes a comprehensive sample collected from 1991 to 2017, examining the muscle-tendon system in 24 anuran species across adult, juvenile, and metamorphic stages. This extensive sample size allows us to investigate consistent anomaly patterns across different developmental stages and anuran families, exploring potential common developmental or genetic factors. Our detailed anatomical examination, encompassing musculature, tendons, and skeletal structures, revealed that 21% of the specimens displayed anomalies, a noteworthy finding considering the extensive sample size and duration of the studied sample. Of these anomalies, 17% affected the locomotor system, predominantly in the upper limbs. Key anomalies included, forelimbs and hindlimbs brachydactyly, rotation in forelimbs, partial kyphotic lordosis, and scoliosis. Notably, the digit 4 in the forelimbs and digits 4 and 5 in the hindlimbs were particularly susceptible to teratogenic effects, indicating possible prolonged exposure during development. Our study also uncovered combinations of anomalies and identified a phenotype similar to Poland syndrome. The findings validate the “Logic of Monsters” (LoMo theory) by Alberch, although the name itself may not be deemed appropriate, showing that developmental disruptions in tetrapods are not random but follow distinct sequences and patterns. The name, while unfortunate, accurately reflects the unusual nature of these developmental anomalies. This contributes to the evolving “Evo-Devo-Path” framework, highlighting the study's importance in understanding developmental disruptions in tetrapods.

The nervous system is distinctive as compared to other tissue systems in human body owing to intricate structural organization. Histological studies played a key role in unveiling complex details of nervous tissue. However, the process of developing suitable staining method for nerve cells was arduous and spanned across almost half a century. The present study explored details of the journey involving quest for propitious staining method in neuroanatomy culminating in promulgation of neuron doctrine at the onset of 20th century. Initial efforts involving hematoxylin (including its diverse modifications) and subsequent adoption of analogous dye-based stains (like Nissl's method) had limited success in visualization of different parts of a nerve cell and structural details of nervous tissue. This was due to inability of dye-based stains to penetrate the connective tissue sheath of nervous tissue. Eventually, advent of metallic stains in form of silver impregnation method (Golgi stain), reduced silver impregnation method with gold stain (Cajal's stain) and silver carbonate staining method of Río-Hortega unraveled the structure of nervous tissue. The evolution of staining methods catalyzed the refinement of theories pertinent to constitution of nervous tissue. Golgi's staining led to emergence of reticular theory (neurons exist as a network) and Nissl's staining was the basis of the concept of Nervösen Grau (nerve cells and glial cells are embedded in mass of gray matter). Finally, Cajal's staining method successfully elucidated the complex anatomy of nerve terminals and resulted in emanation of neuron doctrine (neurons exists as individual units with adjacent connections).

Despite the extensive study of various aspects of the genus Liolaemus, there remains a scarcity of information regarding the osteology of species. In the last two decades, over 100 species have been described within the genus, but still less than 10% of the Liolaemus species includes any osteological data. In this study, we provide a description of the skull of Liolaemus huayra, a taxon closely related to the L. dorbignyi clade (a subset of the L. montanus group). The species was originally described in 2008 based on a few specimens from the Sierra de Quilmes, Tucumán. By obtaining new specimens from a nearby locality (La Ovejería, Catamarca), we were able to prepare the skulls of two males and two females specimens. Despite the limited sample size, we observed intra-specific variability in characters such as postorbital and nasal shape, as well as mandibular curvature. We also document some inter-specific differences based on the scarce osteological information available from other species within the genus. This description constitutes a significant contribution to the osteology of the Liolaemidae clade. We emphasize the importance of detailed descriptions that provide morphological characters suitable for inclusion in comprehensive phylogenetic analyses.

Annual fish have become attractive study models for a wide range of disciplines, including neurobiology. These fish have developed different survival strategies. As a result, their nervous system is under considerable selective pressure when facing extreme environmental situations. Fish from the Austrolebias group exhibit rapid neurogenesis in different brain regions, possibly as a result of the demanding conditions of a changing habitat. Knowledge of cerebral histology is essential for detecting ontogenic, anatomical, or cytoarchitectonic changes in the brain during the short lifespan of these fish, such as those reflecting functional adaptive plasticity in different systems, including sensory structures. The generation of an atlas of Garcialebias charrua (previously known as Austrolebias charrua) establishes its anatomical basis as a representative of a large group of fish that share similarities in their way of life. In this work, we present a detailed study of both gross anatomy and microscopic anatomy obtained through serial sections stained with the Nissl technique in three orientations: transverse, horizontal, and parasagittal planes. This atlas includes accurate drawings of the entire adult brain of the male fish Garcialebias charrua, showing dorsal, ventral, and lateral views, including where emergence and origin of cranial nerves. This brain atlas allows us to understand histoarchitecture as well as the location of neural structures that change during adult neurogenesis, enabling comparisons within the genus. Simultaneously, this atlas constitutes a valuable tool for comparing the brains of other fish species with different behaviors and neuroecologies.

Collections of human remains in scientific and private institutions have a long tradition, though throughout history there has often been variable regard for the respect and dignity that these tissues demand. Recent public scandals around the use of human remains, coupled with an increasing community awareness around accountability in such instances, forces scholars to confront the ethical and moral concerns associated with these collections. This includes specific focus on the acquisition, storage, use, and disposition of these remains, which were often collected with no consent and with little knowledge, or concern, about the individual or their respective culture and practices surrounding death and postmortem treatment. As a response, the American Association for Anatomy convened a Legacy Anatomical Collections Task Force to consider these issues and to develop recommendations to assist those working with these tissues in education, research, and museum collections. This has culminated with the development of Recommendations for the Management of Legacy Anatomical Collections. The recommendations provide both an ethical foundation and practical considerations for the use, storage, and disposition of legacy collections of human tissues, and deliver guidance for establishing appropriate management and oversight, investigating provenance, and engaging with communities of care. While these Recommendations are considered a living document which will change over time as ethical principles concerning human tissue evolve, they currently represent ‘best practice’ recommendations that can guide researchers, teachers, and museum associates as they consider the future of legacy anatomical collections in their care.

Currently, there is no information on the fossil record of Pan-Cheloniidae from the Neogene of the Iberian Peninsula. A well-preserved partial skeleton attributable to this lineage of turtles, from the Middle Miocene of Portugal, is presented here. It preserves much of the anterior half of its carapace, in which the plates remain articulated, as well as several articulated dorsal vertebrae, and an isolated cervical and a caudal vertebrae. The analysis of this Serravallian find shows that it cannot be attributed to a hitherto described taxon. Thus, a new member of Pan-Cheloniidae is defined, Lusochelys emilianoi gen. et sp. nov., improving the relatively limited knowledge about this lineage for the Middle Miocene global record. It represents the first generic and specific systematic attribution for a member of Pan-Chelonioidea in the Neogene record of the Iberian Peninsula.