Natural selection and mutational processes contribution to new genes expression during spermatogenesis

• Grant number: 14/17149-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: December 01, 2014
• End date: July 31, 2016
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Lygia da Veiga Pereira
• Grantee: Júlia Beck Raices
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Gametogenesis is higly important for species survival and speciation. Spermatogenesis - male gametogenesis - can be divided in three phases: mitotic phase (when mitotic divisions take place), meiotic phase (with meiotic divisions and when cells became haploid) and post-meiotic phase (in which spermiogenesis occurs and there are haploid cells). Due to its particular characteristics, such as the existence of haploid cells, spermatogenesis allows us to analyze haploid selection and to compare the expression of retrogenes and retropseudogenes during this phase of development, granting the verification of the importance of this phase in new genes selection and fixation. For a long time it was believed that old genes would be expressed during spermatogenesis as a result of it being a conserved process as its function is common to all beings: produce the sperm cell; it was also believed that during post-meiosis there would be no transcription, today we know that there is transcription during post-meiotic phase and that new genes are highly expressed during this phase. Therefore, this project intends to analyze if there is selection of expressed genes in haploid cells during spermatogenesis in Drosophila melanogaster, also verifying if there is positive selection of genes expressed during this phase. The project will also analyze the definition of retrogenes and retropseudogenes expressed in mouse (Mus musculus) spermatogenesis, as well as compare the expression of this two genes categories during post-meiosis, and will analyze chromatin state data during spermatogenesis in order to verify if the differential expression of retrogenes and retropseudogenes is due to mutational or selection factors. (AU)