Nov. 17, 2009 journal club

Leesa from the Drummond-Barbosa lab will be presenting (our first presenter from that lab!). And although this isn't our first presentation on the ovary, it's been a while! The last one I remember was when we hit on the ovarian germline stem cell controvery in 2006. Interestingly, we'll be coming back to one aspect of this part of ovarian biology with:

Tsc/mTORC1 signaling in oocytes governs the quiescence and activation of primordial follicles, Human Molecular Genetics, in press
Adhikari et al.

This work also has some interesting human health relevance, as Leesa's comments note ...
"A woman's reproductive lifespan is thought to be partially determined by the number of primordial follicles she has at birth. Primordial follicle are maintained in a quiescent state until puberty, at which point they begin to develop into ova and that 'biological clock' starts ticking away. Menopause occurs when the pool of follicles becomes exhausted. But what happens if the clock starts ticking too early? This paper from the Liu lab in Sweden investigates the signaling pathways necessary to maintain primordial follicles in a resting state in mice and finds that insulin and TOR signaling are both necessary, but not sufficient for this process. Over-activation of either pathway leads to premature ovarian failure, or POF. This study is of particular relevance to my work in the Drummond-Barbosa lab. A female Drosophila's reproductive lifespan is determined by how long her ovarian germline stem cells, or GSCs, can be maintained in the niche to produce eggs. Our lab has demonstrated that both insulin signaling and TOR signaling levels (both highly conserved pathways in structure and function) are required for GSC maintenance, and perturbation of either pathway leads to POF. Hope to see you there!"