X chromosome inactivation in the Drosophila male germline

• Applicant: Professor Dr. John Parsch
• Subject Area: Evolutionary Cell and Developmental Biology (Zoology)
• Term: from 2010 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 188666959

Drosophila melanogaster females have two copies of the X chromosome, while males have only one. This difference in copy number between the sexes makes the X chromosome subject to unique evolutionary forces and gene regulatory mechanisms, such as dosage compensation and meiotic sex chromosome inactivation. In the previous phases of this project, we found that the expression of X-linked genes is suppressed in the male germline, but not in other tissues. The genes and molecular mechanisms responsible for this suppression remain unknown. To identify genes involved in this process, we propose to carry out a forward mutagenesis screen of flies carrying a testis-specific reporter gene on their X chromosome. Mutant genes will be identified using a combination of genetic mapping and next-generation genome sequencing. The results will provide the first genetic insights into this chromosome-specific regulatory process. Furthermore, we will use a ubiquitously-expressed reporter gene to determine the effects of X-linkage and proximity to a chromosomal binding site of the dosage compensation complex on gene expression in multiple tissues. This will allow us to determine the influence of dosage compensation on sex-biased gene expression and how it varies among tissues.

• DFG Programme: Research Grants