Meeting Abstract
The annual killifish, Austrofundulus limnaeus, has adapted to survive in harsh and unpredictable environments by entering diapause during embryonic development. Diapause is a pre-programmed exit from normal development that occurs midway through the embryonic period and is characterized by a severe metabolic and developmental arrest. Embryos may also follow an alternative phenotypic trajectory where individuals can instead “escape” entry into diapause and develop continuously to the completion of development. Developmental phenotype is influenced by maternal provisioning and incubation temperature of the embryos. Incubation at 30°C results exclusively in escape embryos while incubation at 20°C results in exclusively diapausing embryos. Previous work has illustrated unique morphological, physiological, biochemical and metabolic profiles in the two developmental trajectories, but these pathways have yet to be described at the gene expression level. We have generated profiles of mRNA gene expression using Illumina RNAseq during early development in embryos developing on both diapause and escape trajectories. These data suggest diapause- and escape-specific gene expression programs that support the entrance into diapause and the high tolerance of environmental stress exhibited by diapausing embryos. These patterns of gene transcription provide a global perspective on genes that may be critical for regulation of metabolic dormancy and survival of anoxia and desiccation. These data are now being used to generate and test the role of specific genes and gene products that regulate diapause and stress tolerance at the organismal level.
