UCLA MARC: Greetings from Stanford!!!

Hi MARCees!

I'm spending my summer at Stanford University as an Amgen Scholar along with Jason and Jennifer from UCLA. It's been an amazing experience! I love the campus and the bay area ! My peers are really interesting and smart, and we are all big science nerds which is awesome:). We have bonded in this short amount of time and have even organized trips to Yosemite, San Francisco and Santa Cruz amongst other fun activities. I am learning a ton everyday especially in lab. My lab focuses on germ stem cells in male fruit flies.
The Drosophila Melanogaster male germ line provides a great model for understanding the process of spermatogenesis. Gonialblasts originate from male germ stem cells that differentiate once they are asymmetrically displaced from the self-renewing origin, known as the niche. In D. Melanogaster, the testes provide a clear depiction of these morphological changes in sperm along their location in reference to the stem cell niche. Strict genetic and post-transcriptional regulation is imperative in this pathway to ensure that spermatogenesis proceeds in a functional manner. A previous publication attested that a mutation in the overgrown hematopoietic organs-31 (oho31) tumor suppressor caused hyperproliferation of D. Melanogaster spermatogonial cyst, an early stem cell stage. However, we believe that their technique generated a mutation in another regulatory gene along this chromosome. We believe that Mediator 20, a subunit of the Mediator complex, causes spermatocyte arrest and hyperproliferation in itself or from interactions with other factors including but not limited to oho31. It is known that the Mediator complex is a member of the RNA polymerase II machinery, an adaptor between transcription factors, and possibly a target of various regulatory proteins. We are interested in elucidating the correlation between Med20 and hyperproliferation of early germ stem cells in the male germ line. Genetic recombination and RNA interference against Med20 will be utilized to compare testis phenotype in Med20 knockdown flies. Furthermore, in situ hybridization with a complementary Med20 probe will be used to localize expression of this gene in the testis. We predict that Med20 mutants will differ from wildtype testis by having a lower amount of mature spermatids and higher degree of germ stem cells in the early stages of spermatogenesis. Our research will provide valuable insight into the regulation mechanism of male germ stem cell proliferation and differentiation.
I'm very fortunate to do research at a different campus because I now have a greater toolbox of molecular techniques and a different perspective of science. Initially, I thought that developmental biology (Stanford lab) would have no similarities with immunology (UCLA lab)- I was wrong. I soon found out that there are many similarities including similar pathways (JAK-STAT) and protein homologs. I am seriously considering coming to Stanford for my Ph.D. There's a great support for grad. students and many professors doing amazing research. I am very exciting to go back to UCLA too and wish everyone a great summer! GO MARC!!!

Best wishes,

Sergio J. Davila

Fruit Fly testis is a great model for understanding stem cells.