LE3 .A278 2017

2017

Stewart, Don

Acadia University

Bachelor of Science

Honours

Biology

Biology

In most animal species mitochondria are inherited maternally, though some species of bivalves are capable of transmitting their mtDNA through a system called “doubly uniparental inheritance” (DUI). Under DUI, daughters still inherit their mother’s mtDNA maternally, but males inherit mtDNA from both parents and segregate it into different tissues (female in the somatic, male in the germ line), creating a mitochondrial lineage that is distinct from the female one. The genomes of freshwater mussels have been shown to contain unique gender-associated open reading frames (ORFs) called M-ORFs, F-ORFs, and H-ORFS (found in males, females, and hermaphrodites respectively) that are strongly expressed within the gonad tissues of their respective sex. The H-ORF is of particular interest because previous work has shown that it is typically a highly divergent version of the F-ORF, and it is hypothesized that sequence divergence may have caused a change in gene function through differential expression. The H-ORF of the hermaphroditic species, the Swan mussel, Anodonta cygnea, as sequenced and characterized; expression was examined using reverse-transcriptase PCR (RT-PCR) and various combinations of newly designed H-ORF primers. Early RT-PCR reactions showed promise for the H-ORF being present in the transcriptome, but the results have been non-duplicable and at this time inconclusive. If the H-ORF is present in the transcriptome, its expression levels should be compared to other mitochondrial genes to determine the likelihood that it is a functional protein. If it is functional, it is possible that it plays a role in the sex determination system of hermaphroditic mussels.

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https://scholar.acadiau.ca/islandora/object/theses:2086