Seasonal gonadal, endocrine, and genetic changes during the reproductive and non-reproductive phases in nocturnal birds of prey

• Grant number: 21/08898-2
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2022
• End date: July 31, 2024
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Claudio Alvarenga de Oliveira
• Grantee: Claudio Alvarenga de Oliveira
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Heriberto Barbosa Moyano

Abstract

In birds, reproductive morphological, physiological, and behavioral adaptations are regulated by neuroendocrine mechanisms in response to specific environmental factors. However, studies related to the knowledge of those mechanisms in birds belonging to the Strigidae family are sporadic. The purpose of this research is to provide innovative knowledge related to reproductive biology of the Tropical Screech-Owl (Megascops choliba), integrating the histological, hormonal, genetic and behavioral aspects. Initially, the seasonal morphological variation of the reproductive tract of males and females collected in the period between 2019-2021 in a rescue center will be evaluated. At the hormonal level, serum concentrations of estradiol (E2) and testosterone (T) will be determined by immunoassay methods in four couples evaluated for 14 months. These animals were kept in captivity conditions, accompanied by continuous image recording. The videos obtained will be analyzed to identify reproductive behaviors (for example, copulation) and relate to the endocrine data obtained. In parallel, electroejaculation methods were applied in 7 males to assess the possible relationship of the presence/absence of sperm with hormone levels. The production capacity of E2 (aromatase gene) and the presence of estrogen and androgen receptor genes in gonadal and brain tissues from free-living males will also be evaluated. The experimental approaches that will be used in this chapter include the quantification of transcripts by polymerase chain reaction techniques and identification of proteins by immunohistochemical methods. It is expected that the results obtained here will serve as a reproductive diagnostic method in owl breeding programs (AU)