Evolution and role of chromosomal territories in the transcriptional regulation of the X chromosome during spermatogenesis in Drosophila

• Grant number: 23/13517-3
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: March 01, 2024
• End date: June 30, 2027
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Maria Dulcetti Vibranovski
• Grantee: Henry Angel Bonilla Bruno
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Since the last century, meiotic sex chromosome inactivation (MSCI) has been observed in a wide range of taxonomic groups with XY sex determination, such as mammals and insects. Therefore, MSCI is considered a crucial process for the proper development of spermatogenesis. In Drosophila, several studies have unequivocally shown a reduction in gene expression from the X chromosome during meiosis. However, the extent of inactivation and the underlying mechanism remain topics of ongoing debate. Recently, our research group discovered that the reduction in gene expression is due to the failure of RNA Polymerase II activation within the chromosomal territory of the X chromosome in D. melanogaster, which aligns with MSCI. Thus, the objective of this project is to study the evolution and role of chromosomal territories in the evolution of MSCI. To achieve this, we will utilize the sister species D. miranda and D. pseudoobscura, both renowned in the study of sex chromosomes due to the presence of X chromosomes in different evolutionary states. By employing molecular cytogenetic and transcriptomic techniques, we will investigate the localization, transcriptional state of chromosomal territories, and differential expression of X chromosomes during the three major phases of spermatogenesis. Our findings will provide a new perspective on the evolution of transcriptional regulation of X chromosomes during spermatogenesis.