Robert E. Braun
Geneticists measure time in generations and celebrate immortality with reproductive success. My lab is driven by a passion to understand the cell biological basis of gamete (sperm and egg) development. We study how germline stem cells balance self-renewal with differentiation. Stem cell self-renewal at the expense of differentiation can cause germ cell tumors while differentiation at the expense of self-renewal can cause sterility. Our long-term goal is to understand the mechanisms that regulate germline stem cell fate. Other research interests include understanding the molecular function of the hormone testosterone in spermatogenesis. Our work has revealed that specialized tight junctions between Sertoli cells, which are integral to the blood/testis barrier, are regulated by testosterone. We are studying how germ cells pass through these tight junctions without compromising barrier function. We are also investigating molecular mechanisms of translational regulation—a major form of gene regulation in both male and female germ cells—during spermatogenesis. We use both forward and reverse genetics to identify the genes involved. Phenotypic analysis includes microscopy, biochemistry and cell physiology.
- Chakraborty P, William Buaas F, Sharma M, Smith BE, Greenlee AR, Eacker SM, Braun RE. Androgen-dependent sertoli cell tight junction remodeling is mediated by multiple tight junction components. Mol Endocrinol. 2014 Jul;28(7):1055-72.
- Gallagher SJ, Kofman AE, Huszar JM, Dannenberg JH, DePinho RA, Braun RE, Payne CJ. Distinct requirements for Sin3a in perinatal male gonocytes and differentiating spermatogonia. Dev Biol. 2013 Jan 1;373(1):83-94.
- Chakraborty P, Buaas FW, Sharma M, Snyder E, de Rooij DG, Braun RE. LIN28A marks the spermatogonial progenitor population and regulates its cyclic expansion. Stem Cells. 2014 Apr;32(4):860-73.