Jennifer D. Gresham, Ph.D. Candidate
I am interested in understanding the evolution and maintenance of self-fertilization and androdioecy in the self-fertilizing mangrove rivulus fish, Kryptolebias marmoratus. Among populations, there is variation in the proportion of males and the frequency that hermaphrodites outcross with those males. This has led to a multi-pronged research approach to understand 1) which factors influence the relative success of outcrossing and selfing as reproductive strategies, 2) how males are maintained within populations, 3) how males find unfertilized eggs (or convince hermaphrodites to lay unfertilized eggs). More broadly, I am interested in understanding the evolution and maintenance of outcrossing across all eukaryotes. The mangrove rivulus fish provides a unique opportunity to test hypotheses in a vertebrate model.
Gresham JD, Marson KM, Tatarenkov A & Earley RL (2020). Sex change as a survival strategy. Evolutionary Ecology 34: 27-40.
Gresham JD, Hanninen AF, Johnson EL, Davis AG, Wong SC, Weinersmith KL, Taylor DS & Earley RL (2019). Hormonal and reproductive flexibility in variable environments. In preparation
Scarsella GE, Gresham JD, Earley RL (2018) Relationships between external sexually dimorphic characteristics and internal gonadal morphology in a sex-changing fish. Journal of Zoology 305:133-140.
Before University of Alabama
Levenhagen DK, Gresham JD, Carlson MG, Maron DJ, Borel MJ, Flakoll PJ (2001). Post-exercise nutrient intake timing in humans is critical to recovery of leg glucose and protein homeostasis. American Journal of Physiology - Endocrinology & Metabolism 280: E982-E993.
Gresham JD, Okamura K, Williams PE, Jabbour K, Flakoll PJ (2000). Gastrointestinal tract, hepatic, hindlimb, and renal recovery of CO2 in vivo. Journal of Applied Physiology 89: 2000-2006.