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."

October 25, 2011 journal club

Our next reproductive biology journal club will be Tuesday, Oct. 25, at 12:15 PM in Room E6519.

Matt Beattie of the Zirkin lab will present -- and he's picked a paper I'm quite keen on:

Paternally-induced transgenerational environmental reprogramming of metabolic gene expression in mammals
Carone et al.
Cell 143: 1084-1096.
Oliver Rando information - department website, EUREKA announcement

Everyone knows how important maternal care and diet are, in the pre-natal period and even pre-conception (example 1; example 2) ... but what about Dad? This journal club paper is one of two papers that came out in the last year that identify some effects of paternal diet on offspring. (FYI, the other is this, by Margaret Morris' group at the University of South Wales.) These papers don't answer all the questions, and in fact, they raise more questions than they answer (IMHO) -- but oh, the interesting questions they raise!

And a bit of shameless promotion -- both Ollie Rando and Margaret Morris are on the program of the upcoming 2012 annual meeting of the American Society of Andrology. (Yall come! abstract deadline is November 1, 2011.)

October 11, 2011 journal club

We're meeting Tuesday, October 11, 12:15 in Room E6519.

Rachel from the Matunis lab will be presenting ... and she's picking something "off the beaten path," but very cool. And actually, it's broader than we might think at first glance:

Royalactin induces queen differentiation in honeybees
Nature 473:478-483
Masaki Kamakura

Related links (thanks for sharing these, Rachel!):
News and Views
Nature News blog

I hope she'll forgive me for quoting her (as I think her comments are very good! -- and I took liberties to highlight some key points):
"As many of the papers nearest and dearest to my heart (and interesting to a broad, reproductive biology audience) have been done in JCs past, I decided to pick a paper that was just really cool. It focuses on the mechanism of how queen bees become queens. Larvae destined for queenhood ingest a substance called royal jelly, which among other things, causes females to have enlarged ovaries and hyper-fertility. The author (yes, singular) isolates the active protein in royal jelly and figures out the pathway through which it mediates it activity. Then, he shows that the protein causes similar effects when he expresses it Drosophila. I think the methods used in this paper are very insightful, and I think we will have a lot of fun doing it."

I agree that there are some very interesting aspects of reproductive biology and function coming from what we might consider unexpected places. Rachel has picked one here that looks like it has some interesting insights into ovarian/gonad physiology. [BTW, another example that I liked over the last year is another cool story from social insects about sperm competition -- an evolutionarily conserved process too (for example ...). It never hurts to read something a little unusual!]

September 27, 2011 journal club

And we're off to the races for AY 2011-2012!
We'll meet Tuesday, Sept. 27, 12:15 in Room E6519.

Many thanks to Elizabeth Ables of the Drummond-Barbosa lab for kicking us off.
She'll be presenting:

Loss of lysine specific demethylase 1 nonautonomously causes stem cell tumors in the Drosophila ovary
S. Eliazer, N.A. Shalaby, and M. Buszczak
PNAS 2011, 108:7032

She says, "I chose this paper because it describes an intriguing role for epigenetic modifiers, specifically the conserved histone demethylase Lsd1, functions (1) during development to regulate the size of the Drosophila germline stem cell (GSC) niche, and (2) in adult somatic tissue adjacent to the GSCs to limit the production of niche-specific signals that maintain GSCs. Cell autonomous epigenetic control of GSCs has been demonstrated by several labs (including the [Erika] Matunis lab), but to my knowledge, this is the the first report demonstrating that epigenetic modifications also control somatic niche cell development and function."