Meeting Abstract
Understanding the genetic mechanisms influencing variation in behavior can provide insight into how different behavioral phenotypes within populations evolve and are maintained. A type of behavioral variation that has received much attention from a behavioral ecology perspective are the distinct phenotypes that comprise male alternative reproductive tactics (ARTs), which are found in a wide array of taxa. One of the classic systems for studying male ARTs are bluegill sunfish, Lepomis macrochirus. In this species, there are two distinct life histories: parental and cuckolder, encompassing three reproductive tactics, parental, satellite, and sneaker. The parental tactic is fixed, whereas individuals who enter the cuckolder life history transition from the sneaker to the satellite tactic as they grow. We used RNAseq to characterize the brain transcriptome of each male tactic during spawning to identify gene categories associated with each tactic and identify potential candidate genes influencing their different spawning behaviors. We found that sneakers had higher levels of gene differentiation compared to the other tactics, suggesting that life history is not the main factor driving differential gene expression. Sneakers had high expression in ionotropic glutamate receptor genes, specifically AMPA receptors, which may be important for increased working spatial memory while attempting to cuckold nests on bluegill colonies. We also found significant expression differences in several candidate genes involved in ARTs that were previously identified in other species and suggest a previously undescribed role for cytosolic 5’-nucleotidase II (nt5c2) in influencing parental male behavior during spawning.
