Postdoc opportunity : Characterized the role of an heterochromatin protein during Drosophila spermatogenesis. The EVOGEN team (https://www.i2bc.paris-saclay.fr/equipe-intragenomic-conflict-and-evolutio= n/) is seeking a highly motivated postdoctoral researcher to participate in a project aimed at elucidating the role of an heterochromatin protein during Drosophila spermatogenesis. Project Spermatogenesis is a complex biological process essential for species survival. One intriguing phenomenon that disrupts this process is sex-ratio (SR) meiotic drive, which alters normal inheritance patterns to bias offspring sex ratios. This mechanism, found in various organisms, manipulates sex chromosome segregation during meiosis, yet its molecular basis remains largely unknown. We study an X-linked (XSR) meiotic drive system, known as the Paris sex-ratio (SR) system, in D. simulans. In males carrying the XSR chromosome, we observe non-disjunction of the sister chromatids of the Y chromosome during meiosis II, resulting in defective spermatids that fail to produce functional sperm. Consequently, XSR carrying males produce strongly female-biased progeny (>90%). The drive is associated with a dysfunctional allele of HP1D2. HP1D2 exhibits three notable features: (1) It belongs to the Heterochromatin Protein 1 (HP1) family, involved in heterochromatin regulation; (2) it originated from a duplication of the autosomal HP1D/Rhino gene; (3) HP1D2 is expressed in spermatogonia and binds the Y chromosome. The goal of this project is to characterize the function of HP1D2 during spermatogenesis and understand its contribution to the Paris SR meiotic drive. Activity The project comprises three major objectives: 1. Characterize the binding sites of HP1D2 on the Y chromosome. The postdoc will develop a CUT&Tag approach in Drosophila testes. 2. Identify HP1D2 protein partners. In collaboration with Peter Andersen (Aarhus University, Denmark), the postdoc will establish a TurboID proximity-labeling strategy in Drosophila testes. 3. Characterize the phenotypic impact of an HP1D2 knockout. The postdoc will design and generate a HP1D2 knockout line using transgenesis and assess its effects on spermatogenesis. Candidate profile - PhD in biology (genetics, genomics, evolutionary biology, or related fields). - Strong interest in molecular biology, evolutionary genetics, and genome regulation. - A solid background in biochemistry (e.g., protein-protein interactions) is a strong asset. Experience with Drosophila, bioinformatics, or confocal microscopy is advantageous but not required. - Ability to work both independently and collaboratively. - Initiative and capacity to lead a research project. Work environment: The Institut de Biologie Int=E9grative de la Cellule (I2BC) is a joint research unit (CNRS, CEA, and Universit=E9 Paris-Saclay) located on the CNRS campus of Gif-sur-Yvette. The institute is made up of around sixty research teams divided into five departments, as well as 17 high-level technological platforms. The project will be conducted within the =93Intragenomic Conflict and Evolution =96 EVOGEN=94 team in the =93Genome Biology=94department, led by C=E9cile Courret, recently established at the I2BC institute. This 2-year postdoctoral position is funded through an ATIP- Avenir grant. The project includes collaboration with Peter Andersen (Aarhus University, Denmark), and the postdoc will have opportunities to visit his team. Compensation and benefits Salary: =803081=96=804653 gross per month (depending on experience) Annual leave + RTT: 44 days Starting date: Before the end of 2026. Applications will be considered on a rolling basis until the position is filled. Want to apply? Please submit your CV and a motivation letter, detailing your previous research experience and professional goals, and contact information for 2 referees, on this platform: https://emploi.cnrs.fr/Offres/CDD/UMR9198-CECCOU-001/Default.aspx For more information contact cecile.courret@i2bc.paris-saclay.fr "cecile.courret@i2bc.paris-saclay.fr" (to subscribe/unsubscribe the EvolDir send mail to golding@mcmaster.ca)