Study of spermatogenesis and sperm maturation in senile dogs

• Grant number: 17/06859-4
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: July 01, 2018
• End date: March 31, 2021
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Camila Infantosi Vannucchi
• Grantee: Maíra Morales Brito
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The present study aims to compare young and senile dogs in regards to the expression of the hormones LH, estrogen and testosterone during spermatogenesis and epididymal maturation; the hemodynamic and vascular characteristics of the testes and epididymis; the sperm morphofunctionality and proteic profile of epididymal fluid. Young dogs within reproductive maturity (1 to 4 years) and senile dogs (over 7 years old), of different breeds, weighing between 10 and 30 kg, will constitute two experimental groups: Group Young and Senile Group. This study will be divided into four experiments. In the experiment 1, the main objective is to evaluate the hemodynamic and vascular characteristics, biometry and homogeneity of the testicular and epididymal parenchyma using two-dimensional ultrasonography, spectral Doppler and color Doppler. In Experiment 2, which aims to analyze the action of hormones LH, estrogen and testosterone on spermatogenesis and sperm maturation, quantitative PCR, immunohistochemistry and Western Blot for the expression of LH (LHR), testosterone (AR) and estrogen (ESR1 e ESR2) receptors in the testis, caput, corpus and cauda of the epididymis and Western Blot on sperm cells will be performed. The Experiment 3 will combine the morphofunctional analysis of spermatozoa during the epididymal transit using computerized analysis of motility, sperm concentration, plasma and acrosomal membrane integrity and mitochondrial membrane potential by flow cytometry, plasma and acrosomal membrane integrity and DNA integrity by stained smears, mitochondrial activity by cytochemical staining and sperm morphology. Lastly, on experiment 4, the aim is to evaluate the proteic profile of epididymal fluid from the caput, corpus and cauda of the epididymis using "gel-free" proteomic analysis. We believed that a more in-depth study of the processes of spermatogenesis and epididymal maturation in the canine species is necessary, allowing to elucidate the pathological characteristics of the ejaculate of dogs at senile age.

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)

BRITO, MAIRA MORALES; DA ROSA FILHO, ROBERTO RODRIGUES; AGOSTINI LOSANO, JOAO DIEGO; VANNUCCHI, CAMILA INFANTOSI. Ageing changes testes and epididymis blood flow without altering biometry and echodensity in dogs. Animal Reproduction Science, v. 228, MAY 2021. (17/06859-4)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

BRITO, Maíra Morales. Spermatogenesis and sperm maturation in aged dogs. 2021. Doctoral Thesis - Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) São Paulo.