Searching for the genomic basis of differentiation in plumage patterning within the Rufous-collared Sparrow (Zonotrichia capensis).

CAMPAGNA LEONARDO; TUBARO PABLO LUIS; BARREIRA ANA S.; LIJTMAER DARÍO A.; LAVINIA OBLANCA PABLO DAMIÁN; LOUGHEED, STEPHEN C.

Virtual (Covid-19)

Congreso; VII North American Ornithological Conference; 2020

The Rufous-collared Sparrow (Zonotrichia capensis) shows phenotypic variation throughout its distribution. In particular, Z. c. australis from southern Chile and Argentina differentiates from other subspecies by lacking the characteristic black lateral crownstripes. We sequenced whole genomes of 18 individuals (9 representing Z. c. australis and 9 from northcentral Argentina) to investigate the genomic changes behind this phenotypic differentiation. Based on the analysis of ~ 11 million SNPs, we detected one main divergence peak (FST = 0.26 ± 0.35) on scaffold 42 that contrast with a background of low genomic differentiation (FST = 0.015 ± 0.018) between Z. c. australis and the other individuals. This ~465-kb region concentrated 90% of outlier SNPs and virtually all fixed differences. This scaffold was mapped to chromosome 5, and outlier SNPs were located within and downstream the Suppression of tumorigenicity 5 gene (ST5), which is involved in cytoskeletal organization and tumorigenicity in humans but has no characterized function in birds. Our results point to this genomic area as one with large effects controlling phenotypic differences between Z. c. australis and other subspecies, proposing this region with no previous association with pigmentation as a candidate gene for plumage color patterning.