Zebra finch ejaculates (Taeniopygia guttata castanotis), testis and somatic tissue (T. g. castanotis and one castanotis x guttata hybrid) sequencing

All songbirds have one special accessory chromosome, the so-called germline-restricted chromosome (GRC), which is only present in germline cells and absent from all somatic tissues. Earlier work on the zebra finch (Taeniopygia guttata castanotis) showed that the GRC is inherited only through the female line, like mitochondrial DNA, and is eliminated from the sperm during spermatogenesis. In this study, we used the two zebra finch subspecies T. g. castanotis of Australia (hereafter castanotis) and T. g. guttata of the Indonesian islands such as Timor to address the issue of inheritance. Specifically, we combined cytogenetic and sequencing data to study (a) the elimination efficiency of the GRC during spermatogenesis, (b) the strictness of the proposed matrilineal inheritance (i.e. expected co-inheritance with the mitochondrial genome) and (c) the genetic variation of the GRC and the co-evolutionary history between GRC and the associated mtDNA haplotypes within the castanotis subspecies.