Dr. Justin Van Goor

Faculty Sponsor: James Bever

I am an evolutionary ecologist broadly interested in community-ecology, mostly using nematodes as a focal taxon. My general research interests and background include the evolution and maintenance of mutualisms, the evolution of antagonism and virulence, sex ratio adjustment, sexual selection (specifically sperm competition), reproductive mode evolution, and genetics (specifically transgenics). I'm interested in using my time as a USDA-NIFA postdoctoral fellow to further develop my bioinformatics, genomics, and phylogenomics skills to compliment my other research interests. 

My first postdoctoral position (2018-2019) was a joint appointment between Iowa State University (under my Ph.D. advisor Dr. John Nason), University of Maryland College Park (under Dr. Carlos Machado), and the Smithsonian Tropical Research Institute (under Dr. Allen Herre). Here, I visited Barro Colorado Island in Panama to examine sex ratio adjustment in Parasitodiplogaster and Ficophagus nematodes associated with pollinating fig wasp mutualists of Panamanian fig species. We found that both divergent groups of nematodes respond similarly to routinely low mating group sizes and produce consistently female-biased sex ratios in ways inconsistent with the typical genetic sex determination found in many animals. We therefore speculated that this female-biased sex ratio adjustment is likely mediated through some novel environmental sex determination mechanism. 

My second postdoctoral position (2019-2021) was with Dr. Eric Haag at the University of Maryland College Park. This represented a significant departure from my previous, largely field-based work, towards honing laboratory-based skills in molecular biology, genetics, and microscopy. Here, I examined a newly discovered sperm surface glycoprotein (Male Secreted Short, or MSS) that is necessary for successful sperm competition in outcrossing Caenorhabditis nematodes, but has been systematically lost in self-fertile, hermaphroditic species. Using transgenics, MSS was introduced into one of these naive self-fertile species (C. briggsae), and mating experiments and microscopy were conducted to examine how MSS works in-vivo. We found that MSS outcompetes all conspecific sperm types, and may do so through enhanced fertilization ability (it may be "stickier" than wildtype sperm). Further, we found that MSS may gain this competitive advantage through being mildly invasive compared to other sperm types (they cut the line, so to speak). Further experiments are on-going back in Maryland to dissect which molecular component may provide this fitness advantage.