Dr. Travis's laboratory investigates the fascinating biology of male germ cells. For life to be transmitted from one generation to the next, these cells must undergo a complex process of differentiation within the male, and then mature functionally within the female reproductive tract during the process of "capacitation." Yet despite their importance, we know remarkably little about many aspects of male germ cell biology at the cell/molecular level. Broad questions of cell biology are investigated using developing male germ cells and sperm as a model. For example, how do specific pathways become compartmentalized to restricted areas within such a highly-polarized cell? How are signaling and metabolic pathways inter-related so that these polarized cells may function as a whole? How are the molecular stimuli for capacitation transduced into the functional changes that enable them to fertilize an egg?
An area of particular interest relevant to these questions is the organization of membrane sub-domains known as "lipid rafts." Dr. Travis has demonstrated that sperm possess these sub-domains, which are enriched in sterols and the protein, caveolin-1. Because removal of sterols from the sperm's plasma membrane is a key stimulus for capacitation, the organization of signaling pathways within lipid rafts is likely to be involved in the regulation of the functional changes associated with capacitation. Furthermore, he has exciting preliminary data that suggest that the lipid environment of the sperm's plasma membrane might be affecting the function of several cellular processes.
In addition to being a basic scientist, he is also a veterinarian with a passion for wildlife conservation. He is integrating his training in these fields in the preservation of genetic diversity by studying methods to preserve spermatogonial stem cells. These cells can replenish themselves on a renewable basis, while also producing cells that will become sperm. The optimization of existing techniques for conservation purposes, and the exploration of novel methods of retaining the genetic information in male germ cells for future breeding, are also actively being pursued in the lab.