Germ cells (or the germline) are the cells that give rise to sperm and eggs, and they are the foundation to sexual reproduction. This lineage of cells is unique from all other somatic cell types, and once sperm and eggs are formed, they can fertilize with each other to generate embryos and fuel the continuous cycle of life. In my lab, we study the molecular mechanisms that underlie two critical cell fate decisions that germ cells must make :
- What makes germ cells distinct from other somatic lineages of cells?
Germ cell differentiation will produce sperm or eggs, which can give rise to embryos that are totipotent and capable of regenerating all cell types within an organism. We are using molecular approaches to study genes that are already known to be involved in these key developmental decisions and also to perform genetic screens to uncover new genes that regulate this process.
- How do germ cells decide their sex?
Germ cells must either choose a male or female program. This decision not only will determine whether sperm or eggs are produced, but the cell biology of male and female germ cells also exhibit clear differences. Some examples include how germline stem cells are regulated, and differential usage of asymmetric divisions. We have recently identified a new gene Phf7 in Drosophila that directs male germline sex determination, and we are further characterizing its roles in germ cell development. We will also use Phf7 as an entry point to map additional molecules and pathways that coordinate this developmental program.
- Yang SY, Chang YC, Wan YH, Whitworth C, Baxter EM, Primus S, Pi H, Van Doren M. Control of a Novel Spermatocyte-Promoting Factor by the Male Germline Sex Determination Factor PHF7 of Drosophila melanogaster. Genetics. 2017 Aug;206(4):1939-1949.
- Wang XR, Ling LB, Huang HH, Lin JJ, Fugmann SD, Yang SY. Evidence for parallel evolution of a gene involved in the regulation of spermatogenesis. Proc Biol Sci. 2017 May 31;284(1855). pii: 20170324.
- Yang SY, Baxter EM, Van Doren M. Phf7 controls male sex determination in the Drosophila germline. Dev Cell. 2012 May 15;22(5):1041-51.
- Murray SM, Yang SY, Van Doren M. Germ cell sex determination: a collaboration between soma and germline. Curr Opin Cell Biol. 2010 Dec;22(6):722-9.
- Yang SY, Fugmann SD, Gramlich HS, Schatz DG. Activation-induced cytidine deaminase-mediated sequence diversification is transiently targeted to newly integrated DNA substrates. J Biol Chem. 2007 Aug 31;282(35):25308-13.
- Yang SY, Fugmann SD, Gramlich HS, Schatz DG. Targeting of AID-mediated sequence diversification by cis-acting determinants. Adv Immunol. 2007;94:109-25.
- Yang SY, Fugmann SD, Schatz DG. Control of gene conversion and somatic hypermutation by immunoglobulin promoter and enhancer sequences. J Exp Med. 2006 Dec 25;203(13):2919-28.
- Hesslein DG, Yang SY, Schatz DG. Origins of peripheral B cells in IL-7 receptor-deficient mice. Mol Immunol. 2006 Feb;43(4):326-34.