Scott Baird (Advisor), Paula Bubulya (Committee Member), Jeffrey Peters (Committee Member)
Master of Science (MS)
Nuclear and mitochondrial genomes have co-adapted through evolution. Interactions between these genomes are required for mitochondrial functions. My goal was to determine how divergence of these interactions affected mitochondrial function and organismal fitness. The impact of divergence between Caenorhabditis briggsae populations and between C. briggsae and its sister species, C. nigoni was assessed. To accomplish this, four sets of hybrid lines were constructed. Each hybrid line possessed the nuclear genome of one parental strain and mitochondria from another parental strain. Two sets of hybrid lines were constructed from strains derived from different C. briggsae populations. The other two were constructed from C.briggsae and C. nigoni parental strains. If a sufficient disruption occurred between the nuclear-mitochondrial interactions within the hybrids, then mitochondrial function and overall fitness was expected to decline. Parental and hybrid strains were scored for embryonic lethality, ovulation rate, and intrinsic growth rate. Significant differences were observed between the C. briggsae : C. nigoni hybrids and their parental strains in embryonic lethality and ovulation rates. However, no significant differences were observed between parental C. briggsae : C. nigoni hybrid lines in their intrinsic growth rates. Abnormal larval phenotypes also were observed in high rates in C. nigoni and higher rates in C. briggsae : C. nigoni hybrids. Most of the abnormal hybrids exhibited a shorter life span and arrested before adulthood, preventing them from producing their optimal amount of offspring. The C. briggsae : C. briggsae hybrids showed significant differences in their ovulation rates compared to their C. briggsae but not their C. nigoni parent strains. No significant differences were detected in embryonic lethality and intrinsic growth rates between C. briggsae parents and C. briggsae hybrids. Therefore, a greater difference in divergence produces a disruption between nuclear and mitochondrial genomic interactions.
Department or Program
Department of Biological Sciences
Year Degree Awarded
Copyright 2014, some rights reserved. My ETD may be copied and distributed only for non-commercial purposes and may not be modified. All use must give me credit as the original author.
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