November 6, 2012 journal club

• When:  Tuesday, Nov. 6, 12:15 PM  
• Where:  Room W4019  
• W4019 is a small classroom on the eastern side of the SPH building (couldn't get E6519 for all of our meetings)

Lauren Matthews (Evans lab) will be presenting:

 

MARF1 Regulates Essential Oogenic Processes in Mice

Su et al., Science (2012) 335:1496-1499

See also the feature on this paper in Biology of Reproduction's "World of Reproductive Biology"

Lauren's comments on her paper choice:

"This paper characterizes an interesting mutant from the Jackson Lab's Reproductive Genomics project.  Mutations in Marf1 (Meiotic arrest female 1) resulted in defects in oocyte meiotic maturation and female infertility.  I chose this paper because one of the defects seen in Marf1 mutant mice was the upregulation of protein phosphatase 2 catalytic subunit (PPP2CB).  Increased PP2 activity contributes to the meiotic maturation defect seen Marf1 mutant mice.  One of the goals of my thesis research project is to characterize a novel pathway regulating PP2A function in mouse oocytes, so I read this paper with great interest!"

October 9, 2012 journal club

• When:  Tuesday, Oct. 9, 12:15 PM  
• Where:  Room W4019  
• W4019 is a small classroom on the eastern side of the SPH building (Alas, we couldn't get E6519 for all of our meetings)

 Hyo Lee (an Evans lab member) will be presenting:  

DNA Damage-induced primordial follicle oocyte apoptosis and loss of fertility require TAp63-mediated induction of Puma and Noxa
Molecular Cell, EPub ahead of print (doi: 10.1016/j.molcel.2012.08.017)
Kerr et al.  [Andreas Strasser lab link]

This paper also was recently highlighted in the lay/science press (such as EurekAlert and ScienceDaily) as well as Biology of Reproduction's regular column, World of Reproductive Biology.  

Hyo's comment on this paper pick: 
    "I thought this article had an interesting combination of genome integrity and reproductive biology.  Preserving fertility in women cancer patients is becoming an increasingly important aspect of cancer treatment, and this paper provides insights into some biological aspects affecting fertility preservation.  In our lab, we have an expert in this field, Mindy Christianson, MD, a fellow in the Division of Reproductive Endocrinology and Infertility in the Department of Gynecology and Obstetrics, who can also share her clinical expertise on this subject during our discussions."

Voilà!  Another paper with broad relevance to the multiple interests in the RBJC group and BMB department!  As always, all welcome!


 

September 25, 2012 journal club

• When:  Tuesday, Sept. 25, 12:15 PM  
• Where:  Room E6519

And we're back! -- from the summer hiatus that is.  
Kate Laws of the Drummond-Barbosa lab will be presenting a paper, hot off the presses in Nature:  

RPN-6 determines C. elegans longevity under proteotoxic stress conditions 
Nature 489:263-268
Vilchez et al. 

Dillin lab page at Salk        Dillin lab personal page

Kate's comments on why she chose this paper (just in case you're looking at the title and thinking, "What a minute, what does this have to do with reproduction?") ...

"Previous studies discussed in this very journal club have noted the inverse correlation between an organism's reproductive capacity and its lifespan, with a lot of attention granted to insulin and insulin-like signaling pathways (which I probably don't need to mention is of particular interest to our lab).  Here, the authors set their sights on another pathway that they hypothesize could contribute to longevity: the ubiquitin proteasome system.  By employing germline-ablated animals, the investigators are able to probe the implications of partitioned resources have on longevity...pretty neat!"  

Thus, broad relevance of this paper with multiple interests in the RBJC group and BMB department!  All welcome!

May 29, 2012 journal club

• When:  Tuesday, May 29, 12:15 PM
• Where:  Room E6519, BSPH

Melvin Rouse from Greg Ball's lab will be presenting -- come out and support him because he has been a real trooper coming over from Homewood campus for our journal club meetings!  (And what the heck, go for some gusto here in the last RBJC of the academic year.)


We'll get to hear something fun and a little different this week.  For those of you who aren't familiar with Greg Ball's lab's work, the general area is behavioral neuroendocrinology, namely, "the interrelation of hormones, brain, and behavior." (and FYI, Greg also has an appointment in Neuroscience).  The work has multiple implications:  how hormones affect the brain, how hormones affect the learning of behaviors, and how various stimuli (including behaviors) can regulate seasonal reproduction.  


Melvin will present two papers related to their work: 

Estradiol-dependent modulation of serotonergic markers in auditory areas of a seasonally breeding songbird. 
Behav Neurosci 126:110-122, Matragrano et al.  [Maney lab website]


Individual differences in the motivation to communicate relate to levels of midbrain and striatal catecholamine markers in male European starlings.
Horm Behav 60:529-539, Heimovics et al. [Riters lab website]

May 15, 2012 journal club

• When:  Tuesday, May 15, 12:15 PM
• Where:  Room E6519, BSPH

May 15 will bring a pinch-hitter presenter -- me, your humble RBJC organizer.  (I had a sympathy for our would-be scheduled presenter, who is mired in a pile of end-of-term assignments.  She agreed she'll present the fall, when she'll be done with her coursework -- hooray!). 

I will present two related papers, mostly focusing on this first one in JCB: 

Ovastacin, a cortical granule protease, cleaves ZP2 in the zona pellucida to prevent polyspermy. 
Burkart et la. (2012)  J Cell Biol 197: 37-44.  [Jurrien Dean's lab website] 


Oocyte-specific oolemmal SAS1B involved in sperm binding through intra-acrosomal SLLP1 during fertilization.  
Sachdev et al. (2012)  Dev Biol 363: 40-51.   [John Herr's lab website]

If you dwell on these titles for a little while, you might think to yourself, "These papers are related?  What is Janice smoking?  Did she give us the wrong papers?"  

I don't blame you for thinking such things.  But scroll down to the bottom of the JCB paper and you'll find: 

      "Note added in proof. While this manuscript was under review, Sachdev et al. (2012. Dev. Biol. doi:10.1016/j.ydbio.2011.12.021) reported on SAS1B, which is the same protein as ovastacin."

So these are two papers, from two different groups, with completely different interests and completely different functions ascribed to this protein.  A thick plot, no? 

May 1, 2012 journal club

• When: Tuesday, May 1, 12:15 PM
• Where: Room E6519, BSPH

Jenn Wang (Seydoux lab) will be presenting two complementary papers, published back-to-back in the March 15 issue of Developmental Cell: 

MITOPLD Is a Mitochondrial Protein Essential for Nuage Formation and piRNA Biogenesis in the Mouse Germline. 
Watanabe et al. 
Dev Cell 20:364

piRNA-Associated Germline Nuage Formation and Spermatogenesis Require MitoPLD Profusogenic Mitochondrial-Surface Lipid Signaling. 
Huang et al. [Frohman lab website]
Dev Cell 20:376.  

Jenn's comments on her paper choices . . . 
(with a little bold font, done by me for emphasis on keywords): 

"These papers revolve around the conserved, membrane-less, electron-dense RNA-protein aggregates in germ cells known as germ granules or nuage. These structures have been found to be crucial for the production of piRNAs, small RNAs that are required for maintaining genome integrity in the germline.  The mechanisms by which germ granules assemble in germ cells is not fully understood and is actively studied.  It has been known for many years that they are associated with mitochondria, (one of the many names for this structure in mammals is "intermitochondrial cement," or IMC) but the functional significance of mitochondrial association is not known. 

In this set of papers, the authors show that MITOPLD, a mitochondrial enzyme, is required for IMC assembly and function.  In the absence of MITOPLD, male mice are sterile, with spermatocytes arrested in meiosis due to retrotransposon derepression.  MITOPLD is the mitochondrial phospholipase D and generates phosphatidic acid, a signaling molecule.  The authors propose that phosphatidic acid may act to signal IMC component assembly or activation.  I picked these papers because they bring up the intriguing cell biology of interorganellar dynamics, with important consequences to the germ cells.  Moreover, these papers are a good example of evolutionary conservation, as zucchini, the Drosophila ortholog of MITOPLD, also acts in piRNA biogenesis. Finally, germ granule assembly is close to the center of my heart (and at the center of my thesis work)."

April 17, 2012 journal club

• When: Tuesday, April 17, 12:15 PM
• Where: Room E6519, BSPH

Lauren McGinnis will be presenting:
Calcium influx-mediated signaling is required for complete mouse egg activation
PNAS 2012, 109: 4169-4174
Miao et al. (Carmen Williams' research group website)

Lauren's comments about this paper:
"Cytosolic calcium oscillations are characteristic of the egg-to-embryo transition. It has been thought that the intracellular calcium that drives egg activation comes from the endoplasmic reticulum, but this paper looks into the necessity for calcium influx across the plasma membrane as a requirement for egg activation, in addition to a function of influx in restoring intercellular calcium stores that are depleted as a consequence of fertilization. I was interested in this paper because the experimental findings potentially provide insight into my project on post-ovulatory aging, and specifically why aged eggs commonly undergo spontaneous egg activation. The Evans lab has found that aged eggs have reduced cortical tension compared to young eggs and this decrease in membrane rigidity may allow additional calcium to enter the cell across the plasma membrane thereby initiating critical signaling pathways to activate the egg."