Dec. 14, 2010 journal club

When and where:
Room W2303, Tuesday, Nov. 30, 12:15.

Hyo from the Evans lab will be presenting:

Granulosa Cell Ligand NPPC and Its Receptor NPR2 Maintain Meiotic Arrest in Mouse Oocytes
Zhang M, Su YQ, Sugiura K, Xia G, Eppig JJ [Eppig Jax website]
Science, 2010, 330: 366-9

Hyo's comment on her paper choice:
"Mammalian oocytes are arrested at prophase I until signals allow for their meiotic maturation. This paper proposes a mechanism by which the arrest is maintained. The paper is especially interesting to me as I have observed differences in spindle morphology and cortical mechanics in mouse eggs matured in vivo vs. in vitro. If time permits, I will share some of my own findings!"

Nov. 30, 2010 journal club

When and where:
Room E6519, Tuesday, Nov. 30, 12:15.

Rachel from the Matunis lab will be presenting:

Functional hierarchy and reversibility within the murine spermatogenic stem cell compartment
Nakagawa et al.
Science, 2010, 328:62-67

Rachel's comment on this paper:
"I picked this one because it beautifully illustrates that the mouse germline is not simply a linear path of cells that is fed by stem cells balancing self renewal and differentiation. Spermatogonia on their way down a path of differentiation can revert toward a more undifferentiated state to keep the germline in balance. Of course we already had hints of this from the awesome model system that is Drosophila but it is always reassuring to find that observations in model organisms hold true up the evolutionary ladder. Previously, in a paper that Becca did for RBJC, (Barroca et al.) it was shown that spermatogonia (no stem cells) could be transplanted into gamma irradiated mice with no functional germline niche, and the transplanted cells could reconstitute the niche. This suggested that these cells were capable of dedifferentiating but this paper is the first to make this observation in vivo in a wildtype (i.e., non-transplanted) situation."

Other papers that Rachel notes are of interest:
Spralding and Fan, "Counterfeiting the family jewels," Cell Stem Cell, 2010, 6:405-406.
Klein et al., "Mouse germ line stem cells undergo rapid and stochastic turnover," Cell Stem Cell, 2010, 7:214-224.

Nov. 16, 2010 journal club

When and where:
Room W2303, Tuesday, Nov. 16, 12:15.
(Note the different room -- we got bumped from E6519 for this week, and will be in the room on the 2nd floor that we used most of last year.)

Newly-defended Leesa (that's DR. LaFever to you!) from the Drummond-Barbosa lab will be presenting:

TGF-β and insulin signaling regulate reproductive aging via oocyte and germline quality maintenance
Luo, Kleeman, Ashraf, Shaw, and Murphy
Cell, 2010, 143:299-312

A nice complement to the Oct. 19 journal club, and recently highlighted in the NYT as well!

Nov. 2, 2010 journal club

When and where:
Room E6519, Tuesday, Nov. 2, 12:15.

Jenn Wang from the Seydoux lab will be presenting:

Bucky ball organizes germ plasm assembly in zebrafish
Bontems, Stein, Marlow, Lyautey, Gupta, Mullins, and Dosch
Current Biology, 19:414-422


Jenn's comment on this paper selection:
"It's long been known that germ cell fate in many animals is specified by a specialized maternal cytoplasm, or germ plasm. However, the components of germ plasm and its assembly mechanisms are only recently beginning to be known. This paper shows that the Bucky ball protein is necessary for germ plasm assembly in zebrafish. Excitingly, they have some evidence that bucky ball may also be sufficient for germ cell formation. If I have time at the end, I will talk a little bit about our work on C. elegans germ granule partitioning, which has been thought to specify worm germ cells."

Oct. 19, 2010 journal club

When and where:
Room E6519 (same as Sept. 21), Tuesday, Oct. 19, 12:15.

Lauren from the Evans lab will be presenting:

L. Lister, A. Kouznetsova, L. Hyslop, D. Kalleas, S. Pace, J. Barel, A. Nathan, V. Floros, C. Adelfalk and Y. Watanabe et al.,
Age-related meiotic segregation errors in mammalian oocytes are preceded by depletion of cohesin and Sgo2
Curr. Biol. 20 (2010), pp. 1511–1521.

... Ah, among the greatest stresses to many a female is the concept that "advanced maternal age" starts at 35. (I get numerous looks of disappointment as I lecture about this in my basic reproductive biology class, and note that it is indeed a biological reality of the way females do meiosis.) Here is Lauren's comments of why she picked this paper:
"It is well known that meiotic segregation errors are more common with increased maternal age, but surprisingly the molecular basis of these meiotic errors are not completely understood. As the trend for women to delay childbearing grows, it becomes critical to understand "what makes a good egg go bad" (this is part of the title of a recent review by Pat Hunt and Terry Hassold). The paper I chose explores the loss of chromosome cohesion as an important factor in age-related meiotic errors. While this is not directly related to my research, this paper helps to address a critical question in the field of reproductive biology that potentially has huge implications for human health."

Also, Hunt and Hassold did a commentary on the three papers on this topic that were published together in this issue of Current Biology:
Hunt and Hassold commentary
Renenkova et al., Curr. Biol. 20 (2010), pp. 1529–1533
Chiang et al., Curr. Biol. 20 (2010), pp. 1522–1528

Oct. 5, 2010 journal club

When and where:
Room E6519 (same as Sept. 21), Tuesday, Oct. 5, 12:15.

Elizabeth from the Drummond-Barbosa lab will be presenting:

Control of mammary stem cell function by steroid hormone signaling
Asselin-Labet et al.
Nature 465: 798-802

As Elizabeth notes, "It's not ovary or testes related, but there is more to 'reproductive biology' (at least in mammals) than just those two organs!" Indeed ... and I say double-bonus that this paper has stem cells and steroids in it.

FYI - Corresponding author Geoff Lindemann website

Seminar of interest, Sept. 27, 2010

This coming Monday will be the Larry L. Ewing Lecture, and the speaker this year is Haifan Lin of Yale University, and the title of his talk is, "A novel small RNA-mediated epigenetic mechanism related to stem cells." (some pretty darn good keywords, huh!?) For those interested, here is a link to a semi-recent (2007) review on piRNAs and the proteins with which they interact; the seminar will present Haifan's latest findings.

Date: Sept. 27, 2010; 4:00 PM (to be followed by a reception)
Place: Sheldon Hall (Room W1214), Bloomberg School of Public Health

Should be a winner (not to mention a nice way to celebrate the life of Larry Ewing) ... please come!

Sept. 21, 2010 journal club

The where and when:
Room E6519 in the SPH, Tuesday, September 21 at 12:15.

We'll venture into developmental biology relevant to reproductive biology, with Erin's presentation of:

Notch and Egft signaling act antagonistically to regulate germ-line stem cell niche formation in Drosophila male embryonic gonads

Kitadate and Kobayashi, PNAS 2010, 107: 14241-14246

RBJC schedule for fall 2010

Our meetings for September-December are below --
every other Tuesday, 12:15-1:30.

• Presenters - The room reservation starts at 12:00, so you can get in a little early for set-up.
• Everyone - Please note that we are in two different rooms (alas, we couldn't get E6519 for all our meetings).

9/21/10 - Erin Stanley (Zirkin lab) - Room E6519 (6th floor, southern side of bldg)
10/5/10 - Elizabeth Ables (Drummond-Barbosa lab) - Room E6519
10/19/10 - Lauren Matthews (Evans lab) - Room E6519
11/2/10 - Jenn Wang (Seydoux lab) - Room E6519
11/16/10 - Leesa LaFever (Drummond-Barbosa lab) - Room W2303
11/30/10 - Min-Young Kim (Drummond-Barbosa lab) - Room W2303
12/14/10 - Hyo Lee (Evans lab) - Room W2303

(Thanks to everyone who stepped up to present in the first part of the academic year! I'll be after more recruits for starting in January 2011.)

BTW, if you want to present a paper that is linked with your own research, great -- but that's not a requirement. Just choose a paper that's interesting and discussion-worthy! For presentation of your own research, we'll experiment with an alternative to what we did last year (i.e., present the paper, then discuss how your research fits in) ... more to come on this when we meet.

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!

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.

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

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!)

March 23, 2009 meeting

Remember all that snow in February? Yeah, I'm trying to block it out too (and the weather this week sure is helping to expunge those memories!). Our next RBJC will be one that was canceled on February 9. Here are the details for March 23:

Place: W2303 (our regular room)
Time: 12:30 (there is another group in W2303 today up to 12:30, and no other appropriately-sized room is available -- but 12:30 works well with the BMB seminar that will run until ~12 noon anyway)

Presenter: Erin Stanley of the Zirkin lab
Paper: "Transgenerational effects of the endocrine disruptor vinclozolin on the methylation pattern of imprinted genes in the mouse sperm"
Reproduction 139:373-379

This will be our first paper (at least in a while) on endocrine disruptors. For more information, see:
NIEHS
EPA
Tulane University's e.hormone site

March 9, 2009 meeting

We'll meet on March 9 at 12:00 noon in Room W2303 (back to our usual room on the second floor of the SPH, around the corner from the Daily Grind).
Min-Young Kim from the Drummond-Barbosa lab will be presenting -

A spindle assembly checkpoint protein functions in prophase I arrest and prometaphase progression
Science (2009) 329:991
Homer, Gui, and Carroll

Min-Young's comment about this paper:
"The anaphase promoting complex (APC) is a multisubunit E3 uibquitin ligase. The APC mediates degradation of cell cycle regulators. Direct binding of the APC activators, Cdc20 or Cdh1, is critical for target specificity and the timing of the APC activation. During mitosis, it is known that a component of Spindle Assembly Checkpoint complex (SAC), BubR1 inhibits the APC/Cdc20 until all chromosomes are properly aligned on metaphase plate. However, it is still unclear how the APC activity is controlled during meiosis. This paper has shown that BubR1 affects the stability of Cdh1 instead of Cdc20 during meiosis in mouse oocytes. This is a noteworthy finding in cell cycle study."

(and a special thank-you to Min-Young for being willing to present in her first year here at JHU!)

February 23, 2010 meeting

Lauren Matthews will be presenting at our next meeting.
Two things to note for this meeting:
TIME - 12:00 noon (we have switched from our 12:30 start time)
PLACE - E6519 (but just for this meeting)

And of course, also the paper! Lauren will be presenting:
Spindle Positioning in Mouse Oocytes Relies on a Dynamic Meshwork of Actin Filaments
Current Biology, 18: 1514-1519
Azoury et al.

Her comment on why she picked this:
"I like this paper because it focuses on how mouse oocytes position their spindle during meiosis. While it is well known that actin is required for spindle positioning, this group was the first to visualize the presence of a cytoplasmic actin meshwork in live mouse oocytes. Cool techniques coupled with some great egg biology = an awesome paper!"

Carnegie Symposium, April 29-30, 2010

A local conference of interest:

The 29th Carnegie symposium (organized by Carnegie post-doctoral fellows),
April 29-30 - Journey of the Germ Cell

There is an excellent line-up of speakers: Ruth Lehman, Jim Priess, Xin Chen, Richard Behringer, Tim Schedl, Gary Wessel, and Bill Sullivan.

Feb. 9 journal club POSTPONED - revised spring schedule

Due to Snowmageddon and the impending Snowmageddon II predicted for tomorrow (not to mention JHU being closed and classes canceled on Tuesday, Feb. 9), we will move Erin Stanley's journal club presentation. Schedule for the remainder of winter-spring will be:

Feb. 23 - Lauren Matthews (Evans lab) - E6519
March 9 - Min-Young Kim (Drummond-Barbosa lab) - W2303
March 23 - Erin Stanley (Zirkin lab) - W2303
April 6 - Mandy Gerolstein (Evans lab) - W2303
April 20 - Shiying Jin (Zirkin lab) - W2303
(May 4 - no RBJC; BMB dept. retreat)
May 18 - Jenn Wang (Seydoux lab) - W2303

Stay safe and warm, everybody!

Revised schedule for winter/spring 2010

Revised schedule, so that we can have a decent room --
We'll be back in our usual room, W2303, with the exception of one date, but now meeting 12:00 noon to 1:30 PM:

Feb. 9 - Erin Stanley (Zirkin lab) - W2303
Feb. 23 - Lauren Matthews (Evans lab) - E6519
(E6519 is a nice large conference room on the 6th floor south side)
March 9 - Min-Young Kim (Drummond-Barbosa lab) - W2303
March 23 - TBD
April 6 - Mandy Gerolstein (Evans lab) - W2303
April 20 - Shiying Jin (Zirkin lab) - W2303
(May 4 - no RBJC; BMB dept. retreat)
May 18 - Jenn Wang (Seydoux lab) - W2303

January 26, 2010 meeting

Matt Beattie plays requests! Mel from the Matunis lab expressed an interest in a certain paper, and Beattie took the bait! (Thanks, Matt! ... and Mel too.)

Somatic Sex Reprogramming of Adult Ovaries to Testes by FOXL2 Ablation
Cell, 2009, 139:1130-1142
Uhlenhaut et al.
Mathias Treier lab website
Video summary of the paper (fun!)

Reminder: We will be in a different room from where we were meeting in the fall. Room number for January 26 is W2205. We are still meeting 12:30 until ~1:30-2:00.

Schedule for winter-spring 2010

Note that we will be in different rooms for the Jan. 26-May 18 meetings:

Jan. 26 - Matt Beattie (Zirkin lab) - W2205
Feb. 9 - Erin Stanley (Zirkin lab) - W2029
Feb. 23 - Lauren Matthews (Evans lab) - W2205
March 9 - Min-Young Kim (Drummond-Barbosa lab) - W2205
April 6 - Mandy Gerolstein (Evans lab) - W2303
April 20 - Shiying Jin (Zirkin lab) - W2303
(May 4 - no RBJC; BMB dept. retreat)
May 18 - Jenn Wang (Seydoux lab) - W2303