Morphohistometric and steroidogenic parameters during testicular and epididymal differentiation in cavy (Galea spixii) fetuses.

Sexual differentiation and steroidogenic mechanisms have an important impact on postnatal gonadal phenotypic development. Thus, establishing the activities that lead to male phenotypic development can provide a better understanding of this process. This study examined the prenatal development of cavies to establish morphological and histometric development patterns and protein and enzyme immunolocalization processes that are responsible for androgen synthesis in the testes and epididymis. Histological and histometric analyses of the diameter of the seminiferous cords and epididymal ducts of male fetuses on Days 25, 30, 40, and 50 were performed, as well as immunohistochemistry of the steroidogenic enzymes 5α-reductase and 17ß-HSD, the androgen receptor, and the anti-Müllerian hormone (AMH). Our findings showed a cellular grouping of gonocytes from Day 30 onward that was characteristic of the seminiferous cord, which was not present in the lumen at any of the studied dates. From Day 50 onward, the differentiation of the three anatomical regions of the epididymis was evident, the head (caput), body (corpus), and tail (cauda), with tissue distinctions. Furthermore, the diameters of the seminiferous cords and epididymal ducts significantly increased with age. On Day 50, the tail showed the greatest diameter of the three regions. The Sertoli and Leydig cells exhibited AMH immunoreactivity at all dates. In addition, the Leydig cells and epididymal epithelial tissue were immunopositive for 5α-reductase, 17ß-HSD, and the androgen receptor; therefore, these factors influenced the development and maintenance of the testis and epididymis during cavy prenatal development.

Surgical Anatomy for Sterilization Procedures in Female Capybaras.

Capybaras are the largest rodents cohabiting with humans within urban and peri-urban green areas and are known by their prolificity. Surgical contraception has been recommended by official organizations as a way to control capybara populations in areas of zoonotic disease transmission, but little data are available concerning surgical anatomy. To obtain objective anatomical descriptions related to reproductive organs, eight female capybaras cadavers were dissected. The stratigraphy of the lateral (flank) and ventral, post-umbilical (on the linea alba) abdominal wall is described as well as the vascular anatomy of reproductive organs and their syntopy with the abdominal viscera. We commented on the access to the uterine tubes and uterine horns for each approach, and for better description of abdominal wall stratigraphy, abdominal ultrasonography was performed in one live female. All of the animals were provenient from "in situ" population management projects that were properly authorized. Similar abdominal wall stratigraphy was found in comparison to domestic mammals, with emphasis on a thick cutaneous muscle, a thin linea alba, and a large, loose cecum. The uterine tubes were easily accessed by bilateral laparotomy, allowing tubal removal/ligation procedures, while uterine horn exposure was more readily reached by a midline post umbilical celiotomy, favoring horn ligature and hysterotomy techniques. This study can help achieve more efficient contraceptive surgeries in capybaras, reducing the total surgical time and enhancing animal welfare.

Digitalização e Impressão Tridimensional de Crânio Canino como Ferramenta Educacional para Estudo Anatômico.

Este trabalho teve como objetivo padronizar a digitalização e impressão 3D de crânios de cães para uso educacional e avaliar a eficácia de modelos anatômicos impressos na disciplina de anatomia do curso de medicina veterinária. Os crânios foram selecionados para escaneamento e criação dos modelos impressos 3D modelados por fusão de deposição (FDM) utilizando acrilonitrila butadieno estireno. Após uma aula teórica sobre anatomia do crânio os modelos impressos 3D e os modelos reais do crânio de cães foram apresentados aos 140 alunos durante a aula prática de ossos. Uma avaliação prática de osteologia foi realizada após um mês que consistiu na identificação de estruturas anatômicas dos ossos do crânio identificados por alfinetes. Os alunos foram divididos em duas turmas para a realização da avaliação; o primeiro grupo fez os testes usando os crânios reais, enquanto o segundo grupo os crânios impressos 3D. O desempenho dos alunos foi avaliado conforme as suas performances no exame prático. No final da disciplina, eles foram convidados a responder a um breve questionário sobre suas experiências individuais. Os resultados do estudo demonstram que as estruturas anatômicas dos crânios impressos 3D eram semelhantes aos crânios reais. Não houve diferença significativa quando se analisou o grau de acertos e erros durante a realização do exame entre aqueles que identificaram as estruturas nos crânios reais ou nos impressos 3D. Conclui-se que é possível construir um acervo dinâmico digital e impresso tridimensional (3D) para estudos da anatomia comparada da espécie canina a partir de crânios reais, e que os crânios 3D podem ser usados como uma excelente ferramenta alternativa ao ensino na anatomia veterinária.

Three-dimensional printing educational anatomical model of the patellar luxation in dogs.

BACKGROUND: Few studies are available for assessing the current situation of 3D printing in veterinary medicine, due to the recent popularization of this technology. This study aimed to simulate a 3D model of the femorotibiopatellar joint of dogs based on the medial patellar luxation. The scanning, editing and printing of the femur, tibia, fibula and patella of a dog from the Laboratory of Anatomy of FMVZ USP were performed. RESULTS: Three femorotibiopatellar joint models were printed: one representing a healthy join without alterations; the second one with the medially deviated tibial tuberosity; and a last one representing the shifted tibial tuberosity and the trochlear sulcus flattened as consequence. The 3D edition consisted of medial rotation of the tibia and tibial tuberosity (22° against the healthy tibia), and the flatten of the medial femoral condyle (0.2 cm) and femoral trochlear groove. After printing, the corresponding measurements were taken with the alterations and the bone models were made with elastics to represent the anatomical components of the dog joint. Finally, the measurements corresponding to the distance from the patellar ligament to the lateral femoral condyle were taken in each specimen, in order to observe the change in position of the ligament according to the occurrence of the bone alterations. CONCLUSION: We printed 3D articular anatomical components of the femurotibiopatellar joint that could be valuable educational tools for the study of medial patellar luxation in dogs.

Three-dimensional digitalized and printed tongue models of the cow, dog, pig, and horse for undergraduate veterinary educationh / Modelos tridimensionales digitalizados e impresos de lengua de vaca, perro, cerdo y caballo para la educación veterinaria de pregrado

SUMMARY: This study aimed to construct three-dimensional (3D) anatomical models of the tongue of domestic mammals of veterinary interest. The tongues were obtained from the didactic collection of the Laboratory of Veterinary Macroscopic Anatomy in the Surgery Department of the School of Veterinary Medicine and Animal Science, University of Sao Paulo. Tongues from a cow, dog, horse, and pig were selected for scanning and creation of the 3D-printed models. The printer used a filamentous thermoplastic material, acrylonitrile-butadiene-styrene (ABS), which was deposited together with a support resin. In addition to the printing of models, an interactive 3D PDF was generated, creating a didactic collection for students. The anatomical characteristics and peculiarity of the tongues were easily identified in the scanned and printed images. The 3D scanning and printing offered an innovative method of visualizing different anatomical structures and, together with the existing methods, can optimize anatomy teaching in an educational context.

RESUMEN: Este estudio tuvo como objetivo construir modelos anatómicos tridimensionales (3D) de la lengua de mamíferos domésticos de interés veterinario. Las lenguas se obtuvieron de la colección didáctica del Laboratorio de Anatomía Macroscópica Veterinaria del Departamento de Cirugía de la Facultad de Medicina Veterinaria y Zootecnia de la Universidad de São Paulo. Se seleccionaron lenguas de vaca, perro, caballo y cerdo para escanear y crear los modelos impresos en 3D. La impresora utilizó un material termoplástico filamentoso, acrilonitrilo-butadieno-estireno (ABS), que se depositó junto con una resina de soporte. Además de la impresión de modelos, se generó un PDF 3D interactivo, creando una colección didáctica para los estudiantes. Las características anatómicas y la peculiaridad de las lenguas se identificaron fácilmente en las imágenes escaneadas e impresas. El escaneo e impresión 3D ofrecieron un método innovador para visualizar diferentes estructuras anatómicas y, junto con los métodos existentes, puede optimizar la enseñanza de la anatomía en un contexto educativo.

Canine Skull Digitalization and Three-Dimensional Printing as an Educational Tool for Anatomical Study.

This article aims to standardize 3D scanning and printing of dog skulls for educational use and evaluate the effectiveness of these anatomical printed models for a veterinary anatomy course. Skulls were selected for scanning and creating 3D-printed models through Fused Deposition Modeling using acrylonitrile-butadiene-styrene. After a lecture on skull anatomy, the 3D-printed and real skull models were introduced during the practical bone class to 140 students. A bone anatomy practical test was conducted after a month; it consisted in identifying previously marked anatomical structures of the skull bones. The students were divided into two groups for the exam; the first group of students took the test on the real skulls, whereas the second group of students took the test on 3D-printed skulls. The students' performance was evaluated using similar practical examination questions. At the end of the course, these students were asked to answer a brief questionnaire about their individual experiences. The results showed that the anatomical structures of the 3D-printed skulls were similar to the real skulls. There was no significant difference between the test scores of the students that did their test using the real skulls and those using 3D prints. In conclusion, it was possible to construct a dynamic and printed digital 3D collection for studies of the comparative anatomy of canine skull species from real skulls, suggesting that 3D-digitalized and-printed skulls can be used as tools in veterinary anatomy teaching.

Effect of racial crossing on the seminal parameters of rams submitted to heat stress / Efeito do cruzamento racial nos parâmetros seminais de carneiros submetidos ao estresse de calor

The aim of this study was to evaluate the effect of racial crossing on seminal parameters of eight Santa Inês and crossbred (Santa Inês x Dorper) rams submitted to heat stress, and to monitor the return of these parameters to previously reported. Before to place the insulation bags, two collects of semen through electroejaculation were performed. The insulation pouches were made with double-layer plastic, internally lined with cotton, and fixed around the spermatic funiculus and scrotum with adhesive tape and bandage remaining on the testes of the animals for seven days. The first collect was performed on the day that the pouches were taken (day 0) and thereafter, every seven days, totalizing 15 measurements. Data were submitted to analysis of variance (ANOVA). The analyzed variables were subjected to Dunnett test at 5% probability to compare the values obtained before treatment with those obtained in the following days. In this study it was found that the animals restored normal seminal parameter after the insulation effects, however, the return rate differed slightly among the studied breeds. The crossbred animals restored the seminal patterns, on average, a week before Santa Inês. It is concluded that the racial crossing influences the semen parameters of rams submitted to heat stress.

O objetivo deste estudo foi avaliar o efeito do cruzamento racial sobre parâmetros seminais de oito carneiros Santa Inês e mestiços, submetidos ao estresse térmico e monitorar o retorno desses parâmetros aos relatos anteriormente. Antes de colocar as bolsas de insulação, foram realizadas duas coletas de sêmen por meio de eletroejaculação. As bolsas de insulação foram confeccionadas com plástico de camada dupla, revestidas internamente com algodão, fixadas ao redor do funículo espermático e escroto com fita adesiva e bandagem, permanecendo nos testículos dos animais por sete dias. A primeira coleta foi realizada no dia em que as bolsas foram retiradas (dia 0) e a partir daí, a cada sete dias, totalizando 15 coletas. Os dados foram submetidos à análise de variância (ANOVA). As variáveis analisadas foram submetidas ao teste de Dunnett a 5% de probabilidade para comparar os valores obtidos antes do tratamento com aqueles obtidos nos dias seguintes. Neste estudo verificou-se que os animais restauraram os parâmetros seminais normais após os efeitos da insulação, porém, a taxa de retorno diferiu ligeiramente entre as raças estudadas. Os animais mestiços restauraram os padrões seminais, em média, uma semana antes da Santa Inês. Conclui-se que o cruzamento racial influencia os parâmetros seminais de carneiros submetidos ao estresse térmico.

Comparative assessment of anatomical details of thoracic limb bones of a horse to that of models produced via scanning and 3D printing.

BACKGROUND: Three-dimensional (3D) scanning and printing for the production of models is an innovative tool that can be used in veterinary anatomy practical classes. Ease of access to this teaching material can be an important aspect of learning the anatomy of domestic animals. In this study, a scanner was used to capture 3D images and a 3D printer that performs die-cast printing was used to produce skeletal models of the thoracic limb of a horse. METHODS: Bones from a horse were selected for scanning and creation of 3D-printed models. The printer used a filamentous thermoplastic material (acrylonitrile-butadiene-styrene [ABS]) which was deposited together with a support resin. Comparisons of the anatomical characteristics (measurements from the original and printed bone) were analyzed to determine the p-value. RESULTS: Bones from the thoracic limb: scapula, humerus, radius and ulna, carpus and phalanges were used to produce digital and physical models for 3D impressions. Then the anatomical characteristics of the 3D printed models were compared with those of the original bones. The p-value was measured to be 0.9126, indicative of a strong evidence of similarity between the 3D-printed models and specimens. Thus, there was no significant statistical difference between the models and the original anatomical parts. CONCLUSIONS: The anatomical characteristics were successfully identified in the 3D-printed copies, demonstrating that models of animal bones can be reproduced using 3D printing technology for use in veterinary education.

Skin development in 14 to 60-day-old Guinea pig fetus / Desarrollo de la piel del feto de conejillo de indias de 14 a 60 días

To contribute knowledge of an important experimental model for studies on skin embryology, a study was carried out to describe the morphological events of the skin during the intrauterine life of Cavia porcellus from the 10th to the 60th day of gestation. Embryos and fetuses were dissected, and the skin of the nasal, cranial, lumbar and anal regions was processed byoptical microscopy. At 30 days the first hairs, called lanugos, were observed in the cranial region. The morphological description showed that a few days can make a great difference in development.

Con el objetivo de contribuir al conocimiento de un importante modelo experimental para estudios sobre embriología de la piel, se llevó a cabo un estudio para describir los eventos morfológicos de la piel durante la vida intrauterina de Cavia porcellus desde el día 10 hasta el día 60 de gestación. Los embriones y los fetos se disecaron y se procesó la piel de las regiones nasal, craneal, lumbar y anal, mediante microscopía óptica. A los 30 días se observaron los primeros vellos, llamados lanugos, en la región craneal. La descripción morfológica mostró que unos pocos días pueden marcar una gran diferencia en el desarrollo.

Digital revolution in veterinary anatomy: confection of anatomical models of canine stomach by scanning and three-dimensional printing (3D) / Revolución digital en anatomía veterinaria: confección de modelos anatómicos del estómago canino mediante escaneo e impresión tridimensional (3D)

Three-dimensional (3D) scanning and printing can contribute to the area of Veterinary Anatomy, producing anatomical models that can be used in teaching. The objective of this project was to apply the 3D digitalization and printing to produce models of the canine stomach, and make these models available as an alternative tool of study in the practical classes of veterinary anatomy. The stomachs of dogs were digitized and printed in 3D models. Anatomical aspects were easily identifies in the models as compared with stomach original. The results of this project clearly demonstrated that the digitalization and 3D printing from the dog stomach come to strongly contribute to the teaching of veterinary anatomy, currently playing an important role by producing replicas which present desirable anatomical characteristics from organ.

El escaneo e impresión tridimensional (3D) puede contribuir al área de Anatomía Veterinaria, produciendo modelos anatómicos que pueden usarse en la enseñanza. El objetivo de este proyecto fue aplicar la digitalización e impresión 3D para producir modelos del estómago canino y hacer que estos modelos estén disponibles como una herramienta alternativa de estudio en las clases prácticas de anatomía veterinaria. Los estómagos del perro fueron digitalizados e impresos en modelos 3D. Los aspectos anatómicos se identificaron fácilmente en los modelos en comparación con el estómago original. Los resultados de este proyecto demostraron claramente que la digitalización y la impresión en 3D del estómago del perro contribuyen en gran medida a la enseñanza de la anatomía veterinaria y que actualmente desempeña un papel importante, al producir réplicas que presentan características anatómicas deseables a partir de órganos.

Morphology, morphometry, ultrastructure, and mitochondrial activity of jaguar (Panthera onca) sperm.

The jaguar is categorized as "Near Threatened". Conservation strategies, therefore, are needed which include use of reproductive biotechniques. For implementation of biotechnique use, the reproductive characteristics of the species must be understood, which is currently not the case. This study, therefore, aimed to describe the detailed morphology of jaguar sperm, and to evaluate the sperm mitochondrial activity. Five male adults were used. Slides stained with Rose Bengal were used for morphometric and morphological analyses. The length and the width of the sperm head were measured, as well as the length of the middle piece, the tail, and the total length. Scanning and transmission electron microscopy were used for ultrastructural analysis. Mitochondrial function was assessed using the marker 3,3'-diaminobenzidine (DAB). The results are expressed as means ± SEM. The most significant morphological abnormalities observed were head (9 ± 1.7%) and tail defects (12.5 ± 3.3%). The width and length of the head were 3.6 ± 0.03 µm and 4.9 ± 0.02 µm, respectively. The middle piece measured 9.7 ± 0.3 µm, the tail measured 54.5 ± 4.4 µm, and the total length of the sperm was 59.5 ± 0.1 µm. Electron-lucent regions and approximately 54 mitochondrial spirals in the middle piece were identified in the nucleus using electron microscopy. The greatest percentages of cells were classified as DAB I (46.6 ± 4.9%) and DAB II (38 ± 4.4%). The data provide detailed information on the sperm characteristics of jaguars and can support research on germplasm conservation for the species.

Morphological tools to evaluate the digestory apparatus in rocky cavy (Kerodon rupestris).

This research describes for the first time the complete morphology of the digestive apparatus of rock cavies. Dissection, light microscopy, and scanning electron microscopy were performed. The oral cavity has: the hard palate without palatine wrinkles and the soft palate; the tongue composed by striated musculature, with presence of vallate, foliated, and fungiform papillae with taste buds and filiform papillae with mechanical function; and, 20 teeth of the hypsodonts type. Esophagus, stomach, small intestine (duodenum, jejunum, and ileum), and the large intestine (cecum, colon, and rectum) are found. The anus is present at the end of the alimentary channel. Organs of digestive tube are composed by four tunics: mucosa, submucosa, muscular, and serosa. The duodenum, jejunum and ileum have villi. Jejunum, ileum and cecum present Lieberkühn crypts. The cecum has mucous glands. Colon and rectum are folded and have goblet cells. Anus presents sebaceous glands. As associated glands it is found the liver with six lobes and gallbladder; a lobulated pancreas; and a pair of each major salivary gland (parotid, mandibular, and sublingual). Parotid glands have serous acini and mandibular and sublingual glands have mucous acini. Pancreas has adenomers. The liver has hepatocytes and portal vein, hepatic artery, and bile duct (portal triad), separated by sinusoids. It is concluded that the digestive apparatus of the rock cavy has variations in the dentition, lingual papillae, and acini of the salivary glands when compared to other rodents. Other variations refer to the well-developed cecum characteristic of herbivorous behavior.

Development of urogenital system in the Spix cavy: A model for studies on sexual differentiation.

This study documented, for the first time, the morphological patterns of differentiation of male and female genital organs of Spix cavy (Galea spixii) using histological and ultrastructural analyses, with immuno-localization of steroidogenic enzymes, cytochromes P450 aromatase (P450arom) and 17α-hydroxylase/17, 20-lyase (P450c17), involved in the synthesis of estrogens and androgens respectively throughout fetal sexual development. Undifferentiated gonads of Spix cavy develop into ovaries in females after 25 days of gestation (DG), exhibiting P450arom immunoreactivity. After 25 DG, paramesonephric ducts develop and form oviducts, uterine horns and cranial portion of the vagina. The caudal portion of the vagina originates from the urogenital sinus, and a vaginal closure membrane is present at the end of gestation. Partial channeling of the urethra into the clitoris occurs after 40 DG, but complete channeling never occurs. A preputial meatus emerges near the tip of organ. In males, undifferentiated gonads develop into testes at 25 DG and develop immunoreactivity for P450c17, which is required for androgens synthesis and likely maintenance of mesonephric ducts. Mesonephric ducts develop subsequently, forming the epididymis and ductus deferens. The pelvic urethra develops after 25 DG with channeling into the penis occurring around 30 DG. This is the first morphological study describing the process of sexual differentiation during gestation in a hystricomorph rodent and one of the most comprehensive analyses conducted in any mammal. Male genital organ development follows the general pattern described in other domestic mammals, but does not include formation of the baculum as occurs in mice and rats. In females, clitoral development includes partial canalization by the urethra and development of a preputial meatus. Further studies are required to clarify the mechanisms involved in the differentiative processes described.

Development of Adrenal Glands from the Embryonic Phase to Puberty in Spix's Yellow-toothed Cavies (Galea spixii, Wagler, 1831)

ABSTRACT Several authors have underscored the importance of establishing parameters in morphological development by gender comparison to establish clinical and pre-clinical assays through the use of experimental models. Current research compares the morphometry of right and left adrenal glands of males and females and describes differentiation of the cortex and medulla tissue during the embryonic, pre-puberty and puberty phases in Spix´s yellow-toothed cavies. Embryos aged 22 (22D), 25 (25D), 30 (30D), 40 (44D) and >50 (50D) days of gestation and neonates aged 15 (15DPN) (DPN= Days postnatal), 30 (30DPN) and 90 (90DPN) days after birth were analyzed. Comparisons included morphometric and histological analysis in all periods described. When compared the right and left adrenal glands, results show that the length and width have statistical differences (p<0.05). Statistical difference between right and left glans for weight occurred only after 30D in males and after 50D in females. When compared male and females, no statistical difference in the right and left glands was extant. In the case of tissue differences, the glomerular zone is the first to emerge after 22D, followed by the fasciculate zone after 25D and by the reticular zone during the post-natal period. Medullar tissue was spread between the cortical tissue at the onset of development, establishing itself at the center of the organ since the end of pregnancy (>50D) up to puberty. Considering tissue differentiation, there was no difference between the adrenal glands of male and female cavies or between the right and left adrenal glands.

Immunolocalization of steroidogenic enzymes in the vaginal mucous of Galea spixii during the estrous cycle.

BACKGROUND: The synthesis of sex steroids is controlled by several enzymes such as17α-hydroxylase cytochrome P450 (P450c17) catalyzing androgen synthesis and aromatase cytochrome P450 (P450arom) catalyzing estrogen synthesis, both of which must complex with the redox partner NADPH-cytochrome P450 oxidoreductase (CPR) for activity. Previous studies have identified expression of steroidogenic enzymes in vaginal tissue, suggesting local sex steroid synthesis. The current studies investigate P450c17, P450aromatase and CPR expression in vaginal mucosa of Galea spixii (Spix cavy) by immuno-histochemical and western immunoblot analyses. METHODS: Stages of estrous cyclicity were monitored by vaginal exfoliative cytology. After euthanasia, vaginal tissues were retrieved, fixed and frozen at diestrus, proestrus, estrus and metestrus. The ovaries and testis were used as positive control tissues for immunohistochemistry. RESULTS: Data from cytological study allowed identification of different estrous cycle phases. Immunohistochemical analysis showed different sites of expression of steroidogenic enzymes along with tissue response throughout different phases of the estrous cycle. However, further studies are needed to characterize the derived hormones synthesized by, and the enzymes activities associated with, vaginal tissues. CONCLUSION: Current results not only support the expression of enzymes involved in sex steroid synthesis in the wall of the vagina, they also indicate that expression changes with the stage of the cycle, both the levels and types of cells exhibiting expression. Thus, changes in proliferation of vaginal epithelial cells and the differentiation of the mucosa may be influenced by local steroid synthesis as well as circulating androgens and estrogens.

Follicular development and morphological changes in the vaginal epithelium during the estrous cycle of Galea spixii.

The current study aimed to determine if characteristics observed in vaginal cytology during the estrous cycle of female SYT cavies corresponded with proliferation of the vaginal epithelium, characterized by proliferating cell nuclear antigen (PCNA) immunolocalization, and with follicular development at different phases of the estrous cycle. After determining estrous cycle phases by vaginal cytology, females were euthanized at metestrus, diestrus, proestrus, and estrus. Histological study of the vaginal epithelium and ovary were then performed. Immunohistochemistry for PCNA in vaginal tissue at each cycle phase was also performed. Superficial cornified cells and early post-ovulatory follicles were found at estrus. Few nuclei below the enucleate superficial cells were immunoreactive to PCNA. At metestrus, the vaginal epithelium underwent desquamation and lost the superficial cornified cells; basal and intermediate cells appeared, and the post-ovulatory follicle formed an early corpus luteum. No PCNA immunoreactivity was observed. At diestrus, the corpus luteum was developed, and the vaginal epithelium contained basal and intermediate cells. There was PCNA immunoreactivity in the cellular nucleus in the germinative stratum of the epithelium. Because of the growth and maturation of ovarian follicles, the vaginal epithelium suffered intense proliferation at proestrus. Vaginal cytology revealed large intermediate cells and nucleated and enucleated superficial cornified cells. In the ovary, mature follicles were present. More apparent immunoreactivity of PCNA in the germinative layer was found. In summary, we inferred that vaginal exfoliative findings matched the proliferation process of the vaginal epithelium. PCNA immunolocalization occurred as well as corresponding follicular development in the ovaries.

Morphology of the adrenal glands of giant anteater (Myrmecophaga tridactyla, Linnaeus, 1758) of wild life / Morfologia das glândulas adrenais de tamanduá-bandeira (Myrmecophaga tridactyla, Linnaeus, 1758) de vida livre

The Myrmecophaga tridactyla (family Pilosa), popularly known in Brazil as the giant anteater is classified as an endangered species by the main survey agencies of biodiversity preservation around the world. The adrenal glands are important organs, which are related to homeostasis of the animal. This study aimed to describe the morphology of the adrenal glands of M. tridactyla, providing data for future studies related to the production of steroid hormones in specimens exposed to different stress factors. The adrenal glands of 14 specimens were used. The glands were measured, photodocumented and described by light microscopy. The adrenals were positioned in the cranial extremity of the kidneys (left and right) and related medially to the caudal vena cava. The right adrenal gland had an elongated shape while the left adrenal gland had pyramidal or triangular shape. The weight was 4.765±0.129g for the right adrenal and 3.975±0.213g for the left adrenal. The length was 4.50±0.14cm for the right adrenal and 4.28±0.11cm for the left adrenal. The width was 2.60±0.13cm for the right adrenal and 2.37±0.12cm for the left adrenal. The thickness was 0.45±0.11cm for the right adrenal and 0.68±0.14cm for the left adrenal. Statistical differences (p<0.05) between right and left adrenals for all values analyzed were observed. Microscopically it was observed a capsule composed by modeled dense connective tissue lining the organ. Below this capsule, from the outermost to the innermost layer, it was observed a cortical region divided into glomerular, fasciculata and reticular zones with a medullar region occupying the center of the organ. Further studies related to steroidogenesis with specimens collected at different periods of the year are necessary, aiming to observe if there are morphological or hormonal variations in the adrenal glands due to seasonal periods. This information would be of great importance because it could reflect the behavioral habits of this species.

O Myrmecophaga tridactyla (família Pilosa), conhecido popularmente no Brasil como Tamanduá- Bandeira, é uma espécie classificada como ameaçada de extinção pelos principais órgãos de levantamento e preservação da biodiversidade no mundo. As glândulas adrenais são importantes órgãos, relacionados com a homeostasia dos animais. Neste estudo, objetivou-se descrever a morfologia das glândulas adrenais de M. tridactyla, fornecendo dados para futuros estudos relacionados à produção de hormônios esteroides em espécimes expostos a diferentes fatores de stress. Esta pesquisa traz a análise das glândulas adrenais em 14 espécimes de M. tridactyla, as quais foram mensuradas, fotodocumentadas, processadas e analisadas por microscopia de luz. Encontrou-se que as glândulas adrenais pares estavam posicionadas na extremidade cranial dos rins e relacionadas medialmente com a veia cava caudal. Sendo que, a glândula adrenal direita possuía formato mais alongado que a glândula adrenal esquerda, a qual apresentou formato piramidal ou triangular. A massa da glândula adrenal direita foi de 4,765±0,129g, enquanto a esquerda pesou 3,975±0,213g. O comprimento foi de 4,50±0,14cm para a glândula direita e 4,28±0,11cm para a esquerda. A largura foi de 2,60±0,13cm para a glândula direita e 2,37±0,12cm para a esquerda. A espessura da glândula direita foi de 0,45±0,11cm e da esquerda foi 0,68±0,14. Foram observadas diferenças estatísticas (p<0,05) entre as glândulas direitas e esquerdas em todas as dimensões analisadas. Com auxílio de microscopia de luz observou-se uma cápsula de tecido conjuntivo denso modelado, revestindo o órgão. Abaixo dessa cápsula, foi possível evidenciar, da camada mais externa para a mais interna, uma região cortical, dividida em zonas glomerular, fasciculada e reticular, com uma região medular ocupando o centro do órgão. Futuros estudos relacionados à esteroidogênese adrenal com espécimes em diferentes épocas do ano poderiam demonstrar se as glândulas adrenais apresentam variações sazonais em sua conformação morfológica ou na produção de hormônios adrenais decorrentes dessas variações, sendo que, estes dados seriam de grande importância, pois poderiam refletir os hábitos comportamentais nesta espécie.

Development and morphological changes in the vaginal closure membrane throughout gestation in Galea spixii (Rodentia: Caviidae).

Present research was carried out in order to perform the monitoring of development, recognizes the type of tissue and describes histological and cellular changes of the vaginal closure membrane (VCM) throughout pregnancy in Galea spixii. The results showed that at 20 days of gestation (DG), the VCM occludes completely the external vaginal ostium. Microscopically, the VCM presented juxtaposed cells, derived from the stratum germinative of the stratified epithelium of vaginal mucosa at 20 DG and areas with cell clusters with the presence of intercellular spaces in the final stages of pregnancy (40-50 DG). At 0 DG, the stratified epithelium of vaginal mucosa presented all strata but at 20 DG presented stratified epithelium without the stratum corneum and stratum granular and showed communicant junctions by desmosomes and interdigitations in the cell membrane compound the VCM. Gradually from 40 to 50 DG the stratum germinative became barely perceptible. Many cells showed apoptotic nuclei and emerged many intercellular spacing. So, the interdigitations and desmosomes were not observed. Here, it was demonstrated for the first time that the VCM is formed after the extinction of the stratum granular and corneum of the vaginal mucosa epithelium, with the proliferation of the cells of stratum germinative and communication and junction through desmosomes and interdigitations of these cells. At the end of pregnancy, cellular apoptosis; the spread of stratum germinative; and, absence of cellular communication and junction may be responsible for the weakening of the VCM and may assist the process of rupture of this membrane.

Morphological characteristics of the tongue of the rock cavy- Kerodon rupestris wied, 1820 (Rodentia, caviidae) / Características morfológicas da língua em mocós- Kerodon rupestris wied, 1820 (Rodentia, caviidae)

The Kerodon rupestris are wild rodents bred in captivity in order to their conservation and development of researches. The aim of this study was describe the morphology of the tongue from eight animals by light microscopy and scanning electron microscopy, beyond macroscopic studies. The tongues of K. rupestris had 3.15 ± 0.28 cm of length; 1.0 ± 0.20 cm width at the root; 0.38 ± 0.10 cm width at the body; and, 1.10 ± 0.09 cm width at the apex. Thickness measurements were 0.50 ± 0.09 cm at the apex; 0.30 ± 0.10 cm at the body; and, 0.70 ± 0.10 cm at the root. The free apex had 0.50 ± 0.10 cm in length. The dorsal surface of the tongue contained the fungiform and filiform papillae at the apex and body; conical papillae and a pairs of vallate papillae at the root, and foliated papillae dorsolaterally positioned in the root region. The proper lamina of the dorsal surface of the tongue was composed by keratinized stratified squamous epithelium, in which lingual papillae were found; and, a rich network of skeletal striated muscle and non-modeled dense connective tissue, in which vessels, nerves, mucous and serous acini and their respective ducts were found. In summary, dorsal surface of the tongue of K. rupestris had filiform and conical papillae with mechanical function, and, fungiform, vallate and foliated papillae with taste buds responsible by gustatory function. Moreover, the tongue of these animals showed some peculiarities as the eminence on the apex in sagittal plane, which needs further studies.

Os Kerodon rupestris são roedores silvestres criados em cativeiro para sua conservação e desenvolvimento de pesquisas. O objetivo deste estudo foi descrever a língua destes animais por meio de microscopia de luz, microscopia eletrônica de varredura e estudos macroscópicos. As línguas de K. rupestris tinham 3,15 ± 0,28 cm de comprimento; 1,00 ± 0,20 cm de largura na raiz, 0,38 ± 0,10 cm de largura no corpo e 1,10 ± 0,09 de largura no ápice. As medidas de espessura foram 0,50 ± 0,09 cm no ápice, 0,30 ± 0,10 cm no corpo e 0,70 ± 0,10 cm na raíz. O ápice livre possuía 0,50 ± 0,10 cm de comprimento. A superfície dorsal da língua continha papilas fungiformes e filiformes no ápice e corpo; papilas cônicas e um par de papilas valadas na raiz; e, papilas foliadas posicionadas dorsolateralmente na região da raiz. A lâmina própria da superfície dorsal da língua estava composta por epitélio estratificado pavimentoso queratinizado, no qual as papilas linguais foram encontradas; e, uma rica rede de músculo estriado esquelético e tecido conjuntivo denso não modelado, no qual veias, nervos e ácinos serosos e mucosos e seus respectivos ductos foram encontrados. Em conclusão, a superfície da língua de K. rupestris apresentou papilas filiformes e cônicas com função mecânica e papilas fungiformes, valadas e foliadas com botões gustativos responsáveis pela função gustativa. Além disso, a língua desses animais apresentou ainda particularidades, como uma eminência no plano sagital do ápice que necessita de futuros estudos.

Intrauterine sexual differentiation: biosyntesis and action of sexual steroid hormones

The objective of this review was to describe sexual differentiation events in mammals, relating them to biosynthesis of sexual steroid hormones and their mechanisms of action. Cholesterol is the precursor of sexual steroid hormone biosynthesis via action of several enzymes converting these hormones. Progestagens hormones serve as substrate for the production of androgens, which in turn serve as substrate for estrogen hormones. These hormones are responsible for sexual differentiation and reproductive cycles of mammals. Sexual differentiation process comprises determining the sexual chromosomes XX or XY + SRY and other genes linked to them, differentiation of gonads in testis or ovary, differentiation of internal and external male or female genital organs from undifferentiated anatomical structures present in the embryo, which is dependent on the presence or absence of testes and the production of anti-Müllerian hormone and testosterone; and secondary sexual differentiation, which is the response of various tissues to hormones produced by the gonads, interacting with genes linked to sexual chromosomes to increase or decrease the differences in sexual phenotype. However, some differences between the sexes and some anomalies of sexual differentiation are not explained only by these sexual hormonal effects, but also by the effect of genes encoded in sexual chromosomes.