GTR Seminar / Topics in Advanced Biological Science
We would like to inform you of the following seminar.
We look forward to your active participation.
Title : Mitosis and Meiosis in Drosophila Germ Cells.
Lecturer：Jean-René HUYNH
名古屋大学客員教授、
CIRB Collège de France, Paris, France ,
CNRS Director of Research 1st class Group Leader
Date : Nov. 9th, 2023 (Thu)
Time : 9:30-11:00
Place : E131 Science E Building
Language：English
Contact : Minoru Tanaka（Ex.2979）
Germline cells produce gametes, which are specialized cells essential for sexual reproduction. Germline cells first amplify through several rounds of mitosis before switching to the meiotic program. In many vertebrate and invertebrate organisms, these mitosis are incomplete resulting in the formation of interconnected groups of cells called germline cysts. We found that mutating the Usp8 gene was sufficient to transform incomplete divisions into complete divisions, and, conversely, overexpressing USP8 in Drosophila germline stem cells was sufficient to create ectopic cytoplasmic bridges with their daughter cells.
Once mitosis stop, germline cells enter meiosis. In the early stages of meiosis, maternal and paternal chromosomes pair with their homologous partner and recombine to ensure exchange of genetic information and proper segregation. These events can vary drastically between species and between males and females of the same species. In Drosophila, in contrast to females, males do not form synaptonemal complexes (SCs), do not recombine, and have no crossing over; yet, males are able to segregate their chromosomes properly. We found that chromosome movements in males are much slower than in females and we demonstrate that this slow dynamic is compensated in males by having longer cell cycles. In agreement, slowing down cell cycles was sufficient to rescue pairing-defective mutants in female meiosis. Our results demonstrate that although meiosis differs significantly between males and females, sex-specific cell cycle kinetics integrate similar molecular mechanisms to achieve proper centromere pairing.
★GTR international students only
This seminar is "GTR Lecture series on multidisciplinary problems (1pt)".
Enroll in gtr e-portfolio (Dead line: Nov.8)．Grades will be judged by report. Report submission from TACT by Nov.23.