Whole-genome resequencing of Dulong Chicken reveal signatures of selection

1. Dulong Chickens (DLCs) live at high altitude (~3000 m) and humidity (~90%), are endemic to the Yunnan province, and have gradually developed unique physiological characteristics, but their genetic basis is still unclear. Using the fixation index (F_ST ) approach, based on whole-genome resequencing, DLCs were analysed to uncover the genomic architecture of the population and candidate genes involved in selection during domestication. 2. A total of 469 candidate genes were obtained to be putatively under selection in DLCs. Further investigations revealed the genic footprint for local adaptation (high-altitude and high-humidity) as the genic signatures that are involved in economic traits (related to egg production). 3. Candidate genes were identified that may be associated with disease resistance, aggressiveness, small body size and positive selection of vision in DLCs. 4. These data revealed loci of selective signals that operate during selection for production at high altitude and humidity.

Genetic diversity and relationship of Dulong chickens using mitochondrial DNA control region

The genetic structure and evolutionary relationship of Dulong chicken with other native Chinese species remained unclear. In this study, the mitochondrial control region was analyzed in total of 343 samples comprising 59 from Dulong chicken and 284 from 8 other Chinese local breeds revealed 51 mutation sites that defined 42 haplotypes. The maximum genetic variation was observed between the Shimian caoke and Pengxian yellow chickens. Phylogenetic analysis revealed that these local chickens mainly scatter in two southwestern clades. Dulong chickens have close relationship with other native chicken. Finding of this study suggests a single matrilineal lineage of indigenous Dulong chickens.