Dr. Kenneth Roberts
Research & Interests
Role of the epididymis in sperm maturation and function. Sperm are produced in the testis and gain the ability to fertilize an egg as they transit the epididymis. During spermatogenesis many germ cell proteins are produced that are necessary for the function of mature sperm. Likewise, as sperm transit the epididymis they acquire proteins necessary for normal function from the epididymal fluid, which is a secretory product of the epididymal epithelium. The purpose of our research is to understand this maturation process.
Our current main focus in on the role of CRISP1, an epididymal protein acquired by the sperm, in the sperm functions of fusion with the egg and in the acrosome reaction. Likewise, the role of CRISP2 and CRISP4, additional CRISP proteins produced in the male reproductive tract, are also under investigation. This work has implications for clinical conditions of sperm dysfunction leading to male infertility.
My lab is also interested in the protein composition of sperm and the origin of sperm proteins. In collaboration with colleagues at Wyeth Research we have undertaken a total proteomic analysis of human sperm to discover potential targets for sperm function. We are using signal-trap cloning to identify and catalog cDNAs from the mouse epididymal epithelium encoding secretory proteins that become part of the sperm proteome.
Vadnais ML, Foster DN and Roberts KP. 2008 Molecular Cloning and Expression of the CRISP Family of Proteins in the Boar. Biology of Reproduction in press
Roberts KP, Ensrud-Bowlin KM, Piehl LB, Parent KR, Bernhardt ML and Hamilton DW. 2008 Association of the Protein D and Protein E Forms of Rat CRISP1 with Epididymal Sperm. Biology of Reproduction, publish before print, 10.1095/biolreprod.108.070664
Roberts KP, Johnston DS, Nolan MA, Wooters JL, Waxmonsky NC, Piehl LB, Ensrud-Bowlin KM, Hamilton DW. 2007 Structure and function of epididymal protein cysteine-rich secretory protein-1. Asian Journal of Andrology 9:508-514
Vadnais ML and Roberts KP, 2007 Effects of Seminal Plasma on Cooling-induced Capacitative Changes in Boar Sperm. Journal of Andrology 28:416-422
Lavers AE, Swanlund DJ, Hunter BA, Tran ML, Pryor JL and Roberts KP. 2006 Effect of Vasectomy on the Function of the Rat Epididymal Epithelium and Vas Deferens. Journal of Andrology 27:826-36.
Roberts KP, Ensrud KM, Wooters JL, Nolan MA, Johnston DS and Hamilton DW 2006 Epididymal Secreted Protein Crisp-1 and Sperm Function Molecular and Cellular Endocrinology 250:122-127
Johnston DS, Wooters JL, Kopf GS, Qiu Y and Roberts KP 2005 Analysis of the Human Sperm Proteome Annals of the New York Academy of Science 1061:190-202.
Roberts KP, Wamstad JA, Ensrud KE, Hamilton DW. 2003 Crisp-1 Inhibition of Rat Sperm Capacitation. Biology of Reproduction Biology of Reproduction 69: 572-581