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 pronephro's 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.

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.