|Does Differential Expression of Ion Channels Contribute to Sexually Dimorphic Communication in Electric Fish?|
|Melissa Proffitt, G. Troy Smith. Indiana University, Bloomington, IN, United States
Sex differences in behavior are ubiquitous, but males and females share most of the same genes. The electric organ discharges of South American electric fish provide a good model for studying mechanisms of sex differences. Closely-related species differ in the direction and magnitude of sex differences in EOD frequency (EODf), and EODf is controlled by a single brain region, the pacemaker nucleus (Pn). EODf is a communication signal that can be used to discriminate species and/or sex. We compared expression of ion channel genes in the Pn of males in females of two congeneric species (Apteronotus albifrons and A. leptorhynchus) that differ in the direction of EODf sexual dimorphism. Preliminary RNAseq data suggests that expression of ion channel genes (KIR 3.1, SCN1b, and KVb2) that may regulate EODf is sexually dimorphic in A. albifrons and/or A. leptorhynchus. We used qPCR to examine gene expression of these three ion channel genes (KIR 3.1, SCN1b, and KVb2). SCN1b expression was greater in A. albifrons than in A. leptorhynchus, but did not differ between males and females. Ongoing experiments are examining sex differences in expression of KIR3.1 and Kvb2.