RNA-seq data for the brood parasitic cuckoo finch (Anomalospiza imberbis)
The cuckoo finch (Anomalospiza imberbis) is an obligate brood parasite that reproduces by laying its eggs in the nests of other species. The hosts of the cuckoo finch include a variety of prinia and cisticola warblers in sub-Saharan Africa. Many of these hosts have evolved the ability to detect and remove foreign eggs, which in turn selected for the evolution of mimetic egg coloration in the cuckoo finch. As this evolutionary arms race progressed, some host species evolved polymorphic egg "signatures," making it more difficult for cuckoo finches to match their eggs, and then in turn, cuckoo finches evolved egg colors and patterns that match both different host species as well as the range of variation within individual host species. Recent research (Spottiswoode et al., 2022, PNAS 119: e2121752119) shows that egg coloration in cuckoo finches is maternally inherited allowing for mothers to pass their egg traits intact to daughters regardless of the host origin of their mates. All of this implies repeated bouts of selection on the non-recombining, female-limited W chromosome with potential consequences for other components of the genome. This study seeks to compare the evolution of W-linked genes, mitochondrial genes, and interacting nuclear-encoded OXPHOS between cuckoo finches and related brood parasites that do not have maternally inherited adaptations. Towards that end, these RNA-seq data were generated to aid in genome annotation.