Meeting Abstract
In order to complete their life cycles, all metazoans require oxygen and water. However, environments are not always forgiving when it comes to constantly providing these basic needs for life. Many metazoans that thrive in highly stressful or variable environments cope by arresting development in and entering into states of metabolic depression and developmental arrest, such as diapause. The annual killifish Austrofundulus limnaeus (Meyers) is possibly the most well described example of vertebrate embryonic diapause, and its embryos have been shown to tolerate extremes in oxygen, salinity, Ultraviolet-C radiation, and water availability. Large-scale genetic analyses have only been recently possible in A. limnaeus with the release of its annotated genome. In this work, we test for positive selection in the A. limnaeus lineage using the PAML software package and include 12 other teleost species as background branches. Additionally, we look for changes within gene families among these taxa using CAFE software, which models gene birth and loss along the phylogenetic tree to assess significance of observed gene family size differences. Our results suggest that there maybe several amino acid sites under selection in the A. limnaeus lineage. Additionally, several gene families have expanded or contracted in species, including A. limnaeus, that are known to be stress tolerant. These results suggest several genes of interest that my be important for extreme stress tolerance and may be ideal targets for future functional studies.
