Meeting Abstract
The annual killifish, Austrofundulus limnaeus, survives in harsh and unpredictable environments through their ability to enter into embryonic diapause. Diapause is a pre-programmed exit from normal development that occurs towards the end of somitogenesis and is characterized by a severe metabolic depression and developmental arrest. Development in this species may also follow an alternative phenotypic trajectory where individuals can instead “escape” entry into diapause and continue to develop until hatching. While varying proportions of diapause embryos can occur within a clutch at 25 degrees C, an incubation temperature of 30 degrees C results exclusively in escape embryos while 20 degrees C results in diapausing embryos. Previous investigations have identified unique physiological, biochemical, and metabolic profiles in embryos developing along the diapause and escape trajectories induced by altered incubation temperatures. Furthermore, these unique molecular programs begin to appear many days prior to any morphological divergence in the two trajectories. I hypothesize that altering the embryonic incubation temperature results in expression of non-coding RNAs that regulate developmental trajectory. To assess the validity of this hypothesis, I generated expression profiles of mRNA and small non-coding RNA genes using Illumina RNA-seq in embryos developing at 20 and 30 degrees C. These data suggest diapause- and escape-specific gene programs that may be regulated by small non-coding RNAs. This coupled analysis of mRNA and small non-coding RNA expression provides an extensive view of gene expression that underlies phenotypic plasticity in vertebrate development and highlights how environmental variation may be integrated with genomic information to determine developmental outcomes.
