427C Poster - 05. Reproduction and gametogenesis
Saturday April 09, 1:30 PM - 3:30 PM
Stonewall promotes germ cell to oocyte transition by promoting heterochromatin maintenance during Drosophila oogenesis
Authors: Noor Kotb 1,2; Ankita Chavan 3; Lydia Proskauer 4; Elliot Martin 2; Madhav Jagannathan 3; Prashanth Rangan 2
Affiliations: 1) Department of Biomedical Sciences/ Wadsworth Center, University of Albany, Albany, NY; 2) Department of Biology/RNA institute, University of Albany, Albany, NY; 3) Department of Biology, Institute of Biochemistry, ,ETH Zürich, Zurich; 4) Colgate University, Hamilton, NY
Keywords: b. oogenesis; f. insulators/boundary elements
During oogenesis, germ cells differentiate into an oocyte, which upon fertilization gives rise to a totipotent zygote. In Drosophila, the transition from germ cell to an oocyte requires SETDB1 dependent heterochromatin formation to silence germ cell differentiation genes after the oocyte specification. These silenced germ cell genes are often interspersed between euchromatic genes that are actively transcribed to promote oocyte fate. As heterochromatin is prone to spreading to euchromatic regions, how such heterochromatic territories remain confined during oogenesis remains poorly understood. Here, we find that the DNA binding protein Stonewall (Stwl), is required to establish a boundary between heterochromatic and euchromatic domains. We find that stwl binds to promoter regions of the silenced germ cell differentiation genes and promotes the maintenance of heterochromatin at these loci. Loss of stwl results in loss of heterochromatin spreading, dysregulation of transcription and loss of oocyte fate resulting in mid-oogenesis death. Thus, during germ cell to maternal transition, Stwl acts a boundary element to maintain heterochromatin to promote an oocyte fate.