Genetic Dissection of Germ Cell Differentiation and Function

Summary
The study of germ cells has shaped our understanding of many basic fundamental processes across
different species. Germ cells share a number of features that have long fascinated biologists. These cells
undergo meiosis to form haploid gametes, they are exceptionally good at repairing DNA damage, they
utilize a number of small RNA pathways to silence transposable elements, and they reprogram their
epigenome back to a state that supports totipotency. Here, we proposed to use the Drosophila ovary as
a model to continue to gain insights into genome stability, germ cell differentiation, and the cell-specific
regulation of mRNA translation and ribosome biogenesis/turnover. Over the last five years, we have
adopted and optimized a number of innovative CRISPR-Cas9- and recombineering-based methods for
manipulating the Drosophila genome. Using these approaches, we have mutated and/or tagged over 100
genes that exhibit enriched expression in Drosophila gonads. This work provides a solid foundation for
our planned efforts over the next five years. We will focus on a number of different but related areas. We
will continue to characterize the highly conserved Germ Cell Nuclear Acidic Peptidase (GCNA) gene and
its function in protecting the integrity of germ cells across species. We will also continue to characterize
how cytoplasmic Rbfox1 controls early germ cell development. Our previous screening efforts have
identified a small number of mutations that exhibit germ cell tumor formation or germ cell loss
phenotypes. The molecule function of the disrupted genes will be characterized using the tools and
methods we have in hand. Lastly, we are in the process of generating a number of innovative tools that
will allow us to better assess ribosome biogenesis and turnover during germ cell development and early
embryogenesis. We are very excited by this proposed work and believe the successful completion of
these projects will have a positive impact on our understanding of germ cell biology and other molecular
processes that impact human health.

Grant Number: 5R35GM144043-05
NIH Institute/Center: NIH
Principal Investigator: Michael Buszczak