November 22, 2011 journal club

• When: Tuesday, Nov. 22, 12:15 PM
• Where: Room E6519, BSPH

Phylis Hetie of the Matunis lab will be presenting:

Wolbachia enhance Drosophila stem cell proliferation and target the germline stem cell niche
Science (2011, hot off the presses) 334:990

Frydman lab website (note the pedigree!)

Some interesting nuggets on Wolbachia:
Ars Technica piece
NSF-funded Wolbachia info site

Abstract: Wolbachia are widespread maternally transmitted intracellular bacteria that infect most insect species and are able to alter the reproduction of innumerous hosts. The cellular bases of these alterations remain largely unknown. Here, we report that Drosophila mauritiana infected with a native Wolbachia wMau strain produces about four times more eggs than the noninfected counterpart. Wolbachia infection leads to an increase in the mitotic activity of germline stem cells (GSCs), as well as a decrease in programmed cell death in the germarium. Our results suggest that up-regulation of GSC division is mediated by a tropism of Wolbachia for the GSC niche, the cellular microenvironment that supports GSCs.

November 8, 2011 journal club

• When: Tuesday, Nov. 8, 12:15 PM
• Where: Room E6519, BSPH

Lauren Matthews of the Evans lab will be presenting two related papers:

Postfertilization autophagy of Sperm Organelles Prevents Paternal Mitochondrial DNA Transmission
Rawi et al., Science, published online October 27

Degradation of Paternal Mitochondria by Fertilization-triggered autophagy in C. elegans embryos
Sato and Sato, Science, published online October 27

Her comments:
"These papers caught my eye because they address an interesting reproductive biology question: are paternal mitochondria selectively eliminated after fertilization and if so, how does this occur? The authors demonstrate that paternal mitochondria are selectively eliminated from the early C. elegans embryo by autophagy in order to ensure maternal inheritance of mtDNA. A 2008 paper in Science showed that autophagy is upregulated after fertilization and is essential for early development of mouse embryos. It will be interesting to see if this mechanism for selective elimination of paternal mitochondria is conserved in mammals."