Thursday, April 22, 2010

Thesis defense of Chris Cherry

One of our own, Chris Cherry of the Matunis lab, will be presenting his thesis defense talk:

Monday, April 26, 2010, 3:30 P.M.
Bodian Conference Room
1830 Building, Suite 2-200

Epigenetically controlled stem cells on steroids

(yeah, I agree -- catchy title!)

Congratulations, Chris!

Thursday, April 15, 2010

April 20, 2010 journal club

We'll be gathering in Room W2303 at 12:30 on Tuesday, April 20.
Shiying Jin from the Zirkin Lab will be presenting:

TGFbeta signaling in male germ cells regulates gonocyte quiesecence and fertility in mice
Dev. Biol. in press
Moreno et al.

Abstract: During testis development, proliferation and death of gonocytes are highly regulated to establish a standard population of adult stem spermatogonia that maintain normal spermatogenesis. As Transforming Growth Factor beta (TGFbeta) can regulate proliferation and apoptosis, we investigated its expression and functions during testis development. We show that TGFbeta2 is only expressed in quiescent gonocytes and decreases gonocyte proliferation in vitro. To study the functions of TGFbeta2, we developed conditional mice that invalidate the TGFbeta receptor type II in germ cells. Most of the knock-out animals die during fetal life, but the surviving adults show a reduced pool of spermatogonial stem/progenitor cells and become sterile with time. Using an organ culture system mimicking in vivo development, we show higher proportions of proliferating and apoptotic gonocytes from 13.5 dpc until 1 dpp, suggesting a reduction of germinal quiescence in these animals. Conversely, a 24-hour TGFbeta2-treatment of explanted wild-type testes, isolated every day from 13.5 dpc until 1 dpp, increased the duration of quiescence. These data show that the TGFbeta signaling pathway plays a physiological role during testis development by acting directly as a negative regulator of the fetal and neonatal germ cell proliferation, and indicate that the TGFbeta signaling pathway might regulate the duration of germ cell quiescence and is necessary to maintain adult spermatogenesis.

Wednesday, April 7, 2010

Two Matunis lab members presenting at Young Investigators' Day

Congratulations, Mel and Becca!

School of Medicine Young Investigators' Day
April 15, 2010, , 4:00 PM, PCTB, Mountcastle Auditorium

Melanie Issigonis
"Regulation of Stem Cell Competition in the Drosophila Testis Niche"
Paul Ehrlich Research Award

Xuting Rebecca Sheng
"Novel Mechanisms for Germline Stem Cell Regeneration"
David Israel Macht Research Award

Friday, April 2, 2010

April 6, 2010 journal club

We'll be gathering in Room W2303 at 12:30 on Tuesday, April 6.
Mandy from the Evans lab will present:

Membrane fusion triggers rapid degradation of two gamete-specific, fusion-essential proteins in a membrane block to polygamy in Chlamydomonas
Development, 2010, doi: 10.1242/dev.044743
Yanjie Liu, Michael J. Misamore, and William J. Snell

(Block to polygamy -- think polygamy = polyspermy.)

If you don't know Chlamydomonas ("Chlamy" for short), it's a great unicellular eukaryotic system with very good genetics that has been used for studies of lots of cool cell biological processes ... including my personal fave, fertilization. For more information:
The entry in the ever-present Wikipedia
Bill Snell's lab website

(BTW, I see that Bill is looking for a post-doc, in case anyone is interested!)