Morphological, morphometric and steroidogenic parameters of the sexual differentiation of the external genitalia in Galea spixii

• Grant number: 16/24040-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date until: August 01, 2017
• End date until: July 31, 2019
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Antônio Chaves de Assis Neto
• Grantee: Amilton Cesar dos Santos
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Galea spixii (preá) is a small rodent that lives in the vegetation of the Brazilian Northeast Caatinga. This species has been bred in captivity due to its importance as an alternative source of food in some regions of Brazil. Studies published with the species have shown that the anatomy of the external genitalia challenges the knowledge related to the processes of sexual differentiation, since the adult females present a peniform clitoris pierced by the urethra, with presence of urethral glands, similar to the penis of the males. It has also been demonstrated that the process of masculinization begins in the intrauterine environment. In this sense, several research groups around the world have used experimental models to deepen research on sexual differentiation and its variations and anomalies. Thus, we believe that the study of the development of the genital organs in the preá may help in the understanding of the diverse mechanisms of sexual differentiation in mammals, which are targets of extensive discussions. Therefore, the present study aims to establish patterns of morphological and morphometric development during sexual differentiation of the external genitalia and immunolocalization and quantitative variations of androgen and estrogen receptors and the androgenic enzyme 5-alpha-reductase in undifferentiated genital tubercles, penis and clitoris during the intrauterine development. The pattern of morphological and morphometric development and cellular and tissue adjustments during genital tubercle formation and channeling of the urethra to the clitoris and penis after sexual differentiation, using transmission and light transmission electron microscopy, respectively, will be established. The molecular mechanisms of sexual differentiation of the external genitalia will also be demonstrated through analyzes of the immunolocalization (through immunohistochemistry) and the protein amount (through Western Blotting) of androgen and estrogen (alpha and beta) receptors and of the androgenic enzyme 5 Alpha-reductase. Sexually undifferentiated genital tubercles, penis and clitoris of concepts from 30 pregnant females will be analyzed. To date, concepts were collected at 20, 30, 40 and term-to-term (late gestation).

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SANTOS, A. C.; CONLEY, A. J.; OLIVEIRA, M. F.; ASSIS NETO, A. C.. Steroidogenesis during prenatal testicular development in Spix's cavy Galea spixii. REPRODUCTION FERTILITY AND DEVELOPMENT, v. 33, n. 6, MAR 2021. (16/24040-0, 13/02535-9)

SANTOS, AMILTON C.; LISBOA-NETO, ANTONIO F. S.; SILVA, INGRID K. L.; PEREIRA, HELTON C. S.; SILVEIRA, JULIA M.; SILVEIRA, ERICK E.; VASCONCELOS, BRUNO G.; ASSIS-NETO, ANTONIO C.. Desenvolvimento do sistema urinário em fêmeas de porquinhos-da-índia (Cavia porcellus). Pesquisa Veterinária Brasileira, v. 39, n. 7, p. 549-560, JUL 2019. (16/24040-0)