Seminar - March 12, 2012

Dr. Jacob Mueller
[link for research paper]
The Whitehead Institute
"Recent Specialization of the Mammalian X Chromosome"

Monday, March 12, 2012
12:00 PM, Room W1020 (Becton-Dickinson Auditorium)
School of Public Health

Seminar - February 28, 2012

Dr. Chen Chen
[links for research paper and recent review]
Samuel Lunenfeld Research Institute, University of Toronto
"Reading arginine methylation in the germline: the royal family of Tudor domain proteins regulates Piwi pathway and spermatogenesis"

Tuesday, February 28, 2012
12:00 PM, Room W1020 (Becton-Dickinson Auditorium)
School of Public Health

Seminar - February 21, 2012

For a number of the next few Tuesdays, journal club time will be usurped by what should be some terrific seminars. All are welcome for:

Dr. Tony DeFalco [click here for recent publication]
Department of Cell Biology, Duke University Medical Center
"Beyond the immune: Macrophages in reproductive and stem cell biology"

Tuesday, February 21, 2012
12:15 PM, Room W1020 (Becton-Dickinson Auditorium)
School of Public Health

Feb. 7 , 2012 journal club

• When: Tuesday, Feb. 7, 12:15 PM
• Where: Room E6519, BSPH

A big thank-you to Hyo Lee (from my lab), who I roped in to starting off our journal club for this academic term. She'll be presenting:

Rhythmic actomyosin-driven contractions induced by sperm entry predict mammalian embryo viability

Nature Communications* 2011, 2:417 (Nat Commun is the Nature Publishing Group's new open access journal, another in the mushroom field of open access journals to pop up in the last year or so ... if you're losing count, so am I!)

Ajduk A, Ilozue T, Windsor S, Yu Y, Seres KB, Bomphrey RJ, Tom BD, Swann K, Thomas A, Graham CF, Zernicka-Goetz M. [lab website -- cool pics!]

The paper has some nice imaging of mouse embryos, revealing cellular events that were known to occur in other early embryos. (C. elegans embryos being especially famous for their cytoplasmic flows, and also are a model for events similar to those that Hyo is interested in in her project.) The authors of this paper also try to make the claim that characteristics of these flows will predict what embryos will produce live births -- something that the Assisted Reproductive Technology world would be quite interested in! But see what you think of the data ...

Dec. 6, 2011 journal club

• When: Tuesday, Dec.6, 12:15 PM
• Where: Room E6519, BSPH

Big thanks to Kate Laws of the Drummond-Barbosa lab for volunteering (quite spontaneously) to present for this journal club meeting!! She'll be presenting:

String (Cdc25) regulates stem cell maintenance, proliferation and aging in Drosophila testis
Inaba, Yuan, and Yamashita [lab link]
Development, 138: 5079-5086

Kate's comments about this paper: "Previous papers from the Yamashita lab have addressed centrosome orientation and cell adhesion in the asymmetric division of Drosophila male GSCs, which is definitely interesting (and came up quite a bit during Xin Chen's lecture here last month). While this paper finds no role for String in spindle orientation of GSC or the somatic stem cells in the testis niche, it does deal with another question that's close to both my heart and the hearts of those in my lab: do stem cells regulate their cell cycle differently than their progeny? Additionally, Yukiko was awarded a MacArthur Genius Grant earlier this year!"

And as a warm-up for journal club, be sure to go support Kate in her alter ego role, Commander Kate of the JHSPH Happy Hour!

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."