03 fev Powerful history that is evolutionary gene content of intercourse chromosomes across diverse songbirds
Songbirds have a species quantity almost comparable to that of animals, and therefore are classic models for learning mechanisms of speciation and intimate selection. Intercourse chromosomes are hotspots of both procedures, yet their evolutionary history in songbirds stays not clear. To elucidate that, we characterize female genomes of 11 songbird types ZW that is having sex, with 5 genomes of bird-of-paradise types newly manufactured in this work. We conclude that songbird intercourse chromosomes have encountered at the least four actions of recombination suppression before their species radiation, creating a gradient pattern of pairwise series divergence termed ‘evolutionary strata’. Interestingly, the latest stratum probably emerged because of a songbird-specific burst of retrotransposon CR1-E1 elements at its boundary, or chromosome inversion regarding the W chromosome. The forming of evolutionary strata has reshaped the genomic architecture of both intercourse chromosomes. We find stepwise variations of Z-linked inversions, repeat and GC articles, along with W-linked gene loss price which are linked to the chronilogical age of strata.