Meeting Abstract

P2.16  Saturday, Jan. 5  MicroRNA regulation of alternative phenotypic development of the annual killifish, Austrofundulus limnaeus ROMNEY, AMIE*; PODRABSKY, JASON; Portland State University; Portland State University arom2@pdx.edu

The annual killifish, Austrofundulus limnaeus, is capable of severe metabolic depression during embryonic development as a facultative phenotype termed diapause. However, a small percentage of genetically related individuals do not enter diapause but instead, “escape” and continue to develop until hatching. Entrance into diapause appears to be regulated by maternal effects and environmental cues experienced by the embryos. We hypothesize that regulation of gene expression underlying these alternate phenotypes is epigenetically controlled through expression of diapause-specific microRNAs. We have investigated the expression of small noncoding RNAs, including microRNAs, during development from fertilization until the 24-somite stage in embryos developing on both diapause and escape trajectories. We also profiled expression of small noncoding RNAs in fertilized embryos collected from females known to produce a high proportion of diapausing and escape embryos. We hope to identify diapause- and escape-specific noncoding RNAs, and use these to identify possible gene regulatory pathways that control entrance into diapause and that may underlie the high tolerance of environmental stress exhibited by diapausing embryos. The patterns of expression of such RNAs will provide an extensive view of their role in tissue phenotype determination and plasticity in this species between the two developmental trajectories. The results of this study will likely have far-reaching implications for the regulation of development within an emerging model vertebrate, as well as for the evolution of vertebrate development.