Jéssica Borghesi

Trend Toward Individualization of the Endocrine and Exocrine Portions of the Giant Anteater Pancreas (Myrmecophaga Tridactyla, Xenarthra)

Considering the physiological importance of the pancreas as an endocrine and exocrine organ, this study described the characteristics of the gross and microscopic morphology of this organ using 16 Myrmecophaga tridactyla individuals. The pancreas was located in the left antimere of the body, was pale in colour and exhibited an elongated shape with a central body and lobulated surface. It was positioned in the abdomen, following the curvatura ventriculi major of the stomach, and was attached to the initial portion of the duodenum. The corpus pancreatis was elongated and showed a caudal curvature of 45°. The pancreas exhibited a facies dorsalis (related to the spleen and stomach) and a facies ventralis (related to the renal capsule and intestine). Macroscopically, a craniodorsal, medial, and caudoventral regions were identified, in addition to the left lobe. Structurally, the organ exhibited two distinct parts: the first had exocrine characteristics, consisting of acini and ducts; the second, which was the endocrine portion, consisted of the pancreatic islets, which were located in the medial, caudoventral and left lobe regions. Ultrastructural analysis identified secretory vesicles containing zymogen granules, mitochondria, Golgi apparatus and rough endoplasmic reticulum in pancreatic centroacinar cells. Morphological data on the anatomy of members of the Xenarthra have revealed important peculiarities of several organs and systems, adding great biological value to the representatives of this group. In addition, these studies significantly contribute not only to knowledge of the biology, taxonomy and, consequently, preservation of these animals but also to the discovery of new experimental models. Anat Rec, 300:1104–1113, 2017.

Development of urinary organs in domestic cat during the embryonic and fetal periods

The embryonic origin of the urogenital system came from the intermediate mesoderm. Kidney development involves three successive renal systems with a fast chronological overlap: the pronephro, the mesonephro, and the metanephro. Due to the lack of specific knowledge about this system in cats the present work aimed to describe their urinary organs development, focusing on the structures seen in pronephro, mesonephro, and metanephro during the embryonic and fetal stages of development. The techniques used in this study were: light microscopy, immunohistochemistry, scanning electron microscopy, and transmission electron microscopy. For that, embryos and fetuses from 12 pregnant mixed‐breed domestic cats in different gestational stages were used to describe the proposed organs. The pronephro is present at early stages of embryonary development in embryos from 15 to 19 days with the presence of pronephros corpuscles, ducts and tubules. The mesonephro is found, in general, between days 17 and 37, and contains mesonephric ducts, mesonephric tubules, and glomeruli. The metanephro is seen since 21 days of pregnancy with the presence of glomeruli, proximal and distal contorted tubules and at day 37, the cortex‐medullary region is already differentiated. The evaluation of these structures enhances the knowledge about embryology of the urinary system in cats, aiding a better anatomical understanding of the system in the specie allowing the correlation with other species.

Sexual Determination and Differentiation During Embryonic and Fetal Development of New Zealand Rabbit Females

The aim of this study was to know the embryonic and fetal development of the female rabbit genital system (Oryctolagus cuniculus ), describing its main phases and the moment of sexual differentiation. Eleven pregnant New Zealand female rabbits were used in different gestational phases. The day of coitus was determined as day 0. For each stage a minimum of two a nimals was considered. The samples were obtained every two days from the ninth day post-coitus (dpc) until the 28 th dpc. The gestational period was divided in two: animals with undifferentiated sex (group 1) and animals with differentiated sex (group 2). The ages of embr yos and fetuses were estimated through the crown-rump method. Subsequently, embryos and fetuses were dissected, fixed and processed to be embedded in paraffin (Histosec). The histological analysis was performed on sections stained with hematoxylin and eosin. Immunohistochemical analysis to determine sexual differentiation was performed on samples from the 16 , 18 and 28 dpc. Desert Hedgehog (Dhh) and Indian Hedgehog (Ihh) primary antibodies, respectively, were used to identify cells of the male and female g erminal epithelium. The immunohistochemical results showed that at the 16 th dpc, female sexual differentiation was evident, since positive expression of the Ihh protein was observed. Sexual differentiation was obtained through histological analysis on the 18 th dpc and through anatomical observation of the external genitalia on the 24 th dpc. Knowing the characteristics of the embryonic and fetal development of the female rabbit genital system as well as the moment of sexual differentiation make it possible to establish bases for future research that address the physiology and pathology of these organs. Thus, any alteration in the chain of events of sexual determination and d fferenti tion must search for an explanation from the knowledge of the possible normal mechanisms affected.

Morphology of the Oligoryzomys nigripes respiratory system

Rodents are important in the transmission of infectious diseases that affect the respiratory tract, including simple infections and those caused by specific pathogens. These animals are natural reservoirs of zoonoses that cause many public health diseases. Basic knowledge on the morphology of these animals is important as basic research is useful for applied studies, such as the development of clinical, therapeutic, surgical and clinical models. Morphological data of respiratory tract in Oligoryzomys nigripes are absent in the literature. Therefore, the aim of this study was to perform a morphological analysis of the respiratory tract of O. nigripes. Five adult females from the environmental reserve in São Joaquim da Barra, São Paulo were used, donated to the Museum of Veterinary Anatomy (FMVZ/USP). Several morphological features follow the same pattern seen in rodents; however, this species showed some differences such as the presence of three lobar bronchi, nonlobed left lung and the right lung constituted by two lobes. Respiratory epithelium lined the whole respiratory tract and was seen using scanning electron microscopy the oval shape of the parenchyma and alveoli.

Egg and fourth instar larvae gut of Aedes aegypti as a source of stem cells

According to the World Health Organization, 2015 registered more than 1.206.172 cases of Dengue in the Americas. Recently, the Aedes aegypti has been not only related to Dengue, but also with cases of Zika virus and Chikungunya. Due to its epidemiological importance, this study characterized the morphology of the embryonated eggs of A. aegypti and provided a protocol to culture stem cells from eggs and digestive tract of fourth instar larvae in order to examine cell biology and expression of markers in these vectors. Cells were isolated and cultured in DMEM-High at 28°C, and their morphology, cell cycle and immunophenotyping were examined. Morphologically, embryos were at the end of the embryonic period and showed: head, thorax, and abdomen with eight abdominal segments. The embryonic tissues expressed markers related to cell proliferation (PCNA), pluripotency (Sox2 and OCT3/4), neural cells (Nestin), mesenchymal cells (Vimentin and Stro-1), and endosomal cells (GM130 and RAB5). In culture, cells from both tissues (eggs and larvae gut) were composed by a heterogeneous population. The cells had a globoid shape and small size. Cell cycle analysis on passage 1 (P1) showed 27.5%±2.0% of cell debris, 68% of cells on G0-G1 phase, 30.2% on S phase, 1.9%±0.5% on G2-M phase. In addition, cells on passage 2 showed: 10% of cell debris, 92.4% of cells on G0-G1 phase, 6.8% on S phase, 0.6% on G2-M phase. Embryonated eggs expressed markers involved with pluripotency (Sox2 and Oct 3/4), mesenchymal cells (vimentin and Stro-1), neural cells (Nestin), and cellular death by apoptosis (Caspase 3). Specific endosomal markers for insect cells (GM130 and RAB5) were also highly expressed. In cell culture of A. aegypti larvae gut the same labeling pattern was observed, with a small decrease in the expression of mesenchymal (vimentin and Stro-1) and neural (Nestin) markers. In summary, we were able to establish a protocol to culture embryonated eggs and larvae gut of A. aegypti, describing the characteristics of undifferentiated cells, as well as the cell cycle and expression of markers, which can be used for biotechnology studies for the biological control of this vector.

Esqueletogênese em punaré (Thrichomys laurentinus- Rodentia, Echimyidae)

The aim of this study was to describe the skeletogenesis in punare (Thrichomys laurentinus). We used 11 embryos and 12 fetuses in different stages of development, allocated into 4 groups. Samples were obtained from the Multiplication Center of Wild Animals, at Federal Rural University of the Semi-Arid, Mossoro/RN, Brazil. After fixed in formalin (10%) or glutaraldehyde (2.5%) the morphological analysis was performed with a magnifying glass, and the macroscopic characteristics were photographed. Analysis of X-rays and alizarin red staining was made to better understand the development of bone structures. In x-ray analysis, it was possible to verify that the embryos showed no radiopacity, unlike fetuses that had gradual radiopacity along of the groups. In group II, there was an increase in radiopacity in the spine, mandibular and maxillary regions. In group III, the radiopacity was increased in the hind limbs, ribs and in the frontal region, and group IV showed higher radiopacity in the thoracic limbs and occipital, temporal and frontal skull. These characteristics were confirmed by histological and alizarin red analysis. We concluded that the knowledge of normal skeletal embryology is critical for understanding of adverse effects caused by nutrition and use of drugs during the development.

Ultrastructural analysis of the spermatogenesis in the guinea pig (Cavia porcellus)

A funcao reprodutiva e um fator de vital compreensao tanto para o estabelecimento de sistemas apropriados de manejo, quanto para o uso de novas especies como modelos animais. Neste estudo atraves da microscopia de luz e eletronica caracterizou-se a fase de desenvolvimento sexual do porquinho-da-India (Cavia porcellus) em especimes de 30, 45 e 90 dias de desenvolvimento. Nos animais de 30 dias, a diferenciacao dos espermatocitos foi visualizada somente na microscopia eletronica de transmissao em leptoteno, zigoteno e paquiteno. Durante a puberdade, houve diferenciacao do epitelio germinativo, formacao do acrossoma, porem nao foram evidenciados espermatozoides, assim, infere-se que a puberdade acontece a partir dos 45 dias de idade. A maturidade sexual foi evidente aos 90 dias de idade. Nossos resultados mostraram que ao longo do desenvolvimento sexual pos-natal do porquinho-da-India, mudancas no epitelio germinativo testicular levam ha alteracoes morfologicas, inclusive com relacao ao desenvolvimento das celulas de Sertoli e de Leydig, as quais estao diretamente relacionadas com a puberdade. Assim, novos subsidios morfologicos sao fornecidos para um melhor entendimento dos parâmetros reprodutivos desta especie, a fim de viabilizar sua utilizacao como modelo animal no campo da biologia reprodutiva.