Study of meiotic X chromosome inactivation by gene expression analyses of the Drosophila melanogaster spermatogenesis

Abstract

Chromosomal sexual differentiation through evolution has resulted in a loss of similarity between sex chromosomes, leading several consequences in the dosage between them and their behavior. During meiosis, these differences trigger a silencing mechanism of these unpaired sex chromosomes, such as Meiotic Sex Chromosome Inactivation (MSCI), which is the process of early transcriptional silencing of the sex chromosomes that occurs during the meiotic phase of spermatogenesis. Scientists have investigated the existence and impact of MSCI on D. melanogaster and some aspects related to spermatogenesis. However, different results had repercussions in a debate in the literature on the subject. Although D. melanogaster spermatogenesis presents a down-regulation of X chromosome, the level of the reduction of X-linked expression and the precise time in which it occurs is still unknown. In order to investigate the impact of MSCI on Drosophila, this project intends to perform a gene expression analysis of the three major phases of D. melanogaster spermatogenesis: mitosis, meiosis, and post meiosis. The data of this analysis will be sequenced by the Next Generation Sequencing RNA-seq, which is a sequencing technology that allows more sensitive and broader identification of the genes expression than microarrays techniques. (AU)