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.

Intrauterine exposure to bisphenol A promotes different effects in both neonatal and adult prostate of male and female gerbils (Meriones unguiculatus).

Substances that mimic endogenous hormones may alter the cell signaling that govern prostate development and predispose it to developing lesions in adult and senile life. Bisphenol A is able to mimic estrogens, and studies have demonstrated that low levels of exposure to this compound have caused alterations during prostate development. The aim of this study was to describe the prostate development in both male and female neonatal gerbils in normal conditions and under exposure to BPA during intrauterine life, and also to analyze whether the effects of intrauterine exposure to BPA remain in adulthood. Morphological, stereological, three-dimensional reconstruction, and immunohistochemical methods were employed. The results demonstrated that in 1-day-old normal gerbils, the female paraurethral glands and the male ventral lobe are morphologically similar, although its tissue components-epithelial buds (EB), periurethral mesenchyme (PeM), paraurethral mesenchyme (PaM) or ventral mesenchymal pad (VMP), and smooth muscle (SM)-have presented different immunolabeling pattern for androgen receptor (AR), and for proliferating cell nuclear antigen (PCNA). Moreover, we observed a differential response of male and female prostate to intrauterine BPA exposure. In 1-day-old males, the intrauterine exposure to BPA caused a decrease of AR-positive cells in the PeM and SM, and a decrease of the proliferative status in the EB. In contrast, no morphological alterations were observed in ventral prostate of adult males. In 1-day-old females, BPA exposure promoted an increase of estrogen receptor alpha (ERα) positive cells in PeM and PaM, a decrease of AR-positive cells in EB and PeM, besides a reduction of cell proliferation in EB. Additionally, the adult female prostate of BPA-exposed animals presented an increase of AR- and PCNA-positive cells. These results suggest that the prostate of female gerbils were more susceptible to the intrauterine BPA effects, since they became more proliferative in adult life. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1740-1750, 2016.

Aspectos de manejo e condições genitais que podem constituir ameaça à longevidade reprodutiva de garanhões / Management aspects and genital conditions that may threaten the reproductive longevity of stallions

A longevidade reprodutiva de garanhões de potencial genético elevado constitui um objetivo desejado. Adequar o manejo de garanhões pode não ser uma tarefa fácil, considerando que vários aspectos simples, porém importantes, muitas vezes não são praticados. Essa realidade parece ter se agravado após a disponibilidade de novas biotecnologias da reprodução. Confinamento em cocheiras oferece condições contrárias às funções fisiológicas influentes na longevidade reprodutiva. Muitos garanhões confinados desenvolvem distúrbios de comportamento e metabólico. A ingestão de alimento na presença de ansiedade e compulsão contribui para aumento de peso corporal e predisposição a ocorrência de cólicas. Garanhões obesos estão em risco de inflamação além dos limites fisiológicos, acarretando possibilidade de lesões e sequelas. Além desses fatores relacionados ao manejo, essa apresentação se refere a afecções que ameaçam a longevidade reprodutiva do garanhão, entre elas priapismo, traumatismos, feridas, parafimose, tumores e torsão do cordão espermático.(AU)

Reproductive longevity of stallions with high genetic potential is a desired goal. Adapting the management of stallions may not be an easy task, considering that several simple but important aspects are often not practiced, what seems to have worsened after the availability of new biotechnology of reproduction. Live at stables offers conditions contrary to physiological functions in reproductive longevity and many stallions confined develops behavioral and metabolic disorders. Eating with anxiety of compulsion contributes to increased body weight and possibility of colic. Obesity in stallions carries risk of the inflammation through the physiological limits with possibility of lesions and sequels. In addition to these factors related to management, this presentation refers to conditions that threaten the reproductive longevity of Stallion, including priapism, trauma, wounds, paraphimosis, tumors and torsion of the spermatic cord.(AU)

Aspectos de manejo e condições genitais que podem constituir ameaça à longevidade reprodutiva de garanhões / Management aspects and genital conditions that may threaten the reproductive longevity of stallions

A longevidade reprodutiva de garanhões de potencial genético elevado constitui um objetivo desejado. Adequar o manejo de garanhões pode não ser uma tarefa fácil, considerando que vários aspectos simples, porém importantes, muitas vezes não são praticados. Essa realidade parece ter se agravado após a disponibilidade de novas biotecnologias da reprodução. Confinamento em cocheiras oferece condições contrárias às funções fisiológicas influentes na longevidade reprodutiva. Muitos garanhões confinados desenvolvem distúrbios de comportamento e metabólico. A ingestão de alimento na presença de ansiedade e compulsão contribui para aumento de peso corporal e predisposição a ocorrência de cólicas. Garanhões obesos estão em risco de inflamação além dos limites fisiológicos, acarretando possibilidade de lesões e sequelas. Além desses fatores relacionados ao manejo, essa apresentação se refere a afecções que ameaçam a longevidade reprodutiva do garanhão, entre elas priapismo, traumatismos, feridas, parafimose, tumores e torsão do cordão espermático.

Reproductive longevity of stallions with high genetic potential is a desired goal. Adapting the management of stallions may not be an easy task, considering that several simple but important aspects are often not practiced, what seems to have worsened after the availability of new biotechnology of reproduction. Live at stables offers conditions contrary to physiological functions in reproductive longevity and many stallions confined develops behavioral and metabolic disorders. Eating with anxiety of compulsion contributes to increased body weight and possibility of colic. Obesity in stallions carries risk of the inflammation through the physiological limits with possibility of lesions and sequels. In addition to these factors related to management, this presentation refers to conditions that threaten the reproductive longevity of Stallion, including priapism, trauma, wounds, paraphimosis, tumors and torsion of the spermatic cord.