ANALYSIS OF THE MYSTERIOUS GERMLINE RESTRICTED CHROMOSOME IN ZEBRA FINCH

Songbirds have an unusual genomic element which is only found in their germ cells, known as the germline-restricted chromosome (GRC). Early in embryonic development it is eliminated from all somatic tissue in these birds. In zebra finch, a well-studied animal model for neuroendocrinology and vocal learning, the GRC comprises the longest finch chromosome at over 120 million base pairs in both sexes. Up until 2018, the only genomic GRC sequence known was a non-coding repetitive sequence. Since then, it has been found to contain over a hundred protein-coding genes. This work aims to learn more about the genes and sequences that reside on the GRC. Through this work I was the first to identify positive selection on a GRC gene. I was also involved in developing methods to computationally separate GRC from non-GRC which resulted in the identification of approximately 55 million base pairs of GRC sequence.