A High-Quality Assembly Reveals Genomic Characteristics, 1 Phylogenetic Status and Causal Genes for White Feather of 2 Indian Peafowl

Abstract

Background : Indian peafowl ( Pavo cristatus ) attracts people's attention because of the exclusively dazzling phenotypic characteristics. However, little is known about the phenotypic evolution and phylogeny of Indian peafowl at the whole-genome level. So far, there has been no report on the genetic mechanism of the formation of white feather in white feather peafowl. Results : This study assembled a draft genome of Indian peafowl with a genome size of 1.05 Gb (the sequencing depth is 362×), and N50 of the contig and scaffold was up to 6.2 Mb and 11.4 Mb, respectively. Compared with other birds, Indian peafowl changed in terms of metabolism, immunity, skeletal development and feather development, which provided a novel insight into the phenotypic evolution of peafowl, such as the large body size and feather morphologies. It was confirmed that the phylogeny of Indian peafowl was closer to that of turkey than that of chicken. Specially, it was identified that PMEL was a causal gene leading to the formation of white plumage in blue and white feather peafowl. Conclusions: This study provides a peafowl genome with high-quality as well as a novel understanding in the phenotypic evolution and phylogeny of peafowl among other birds. The results contribute a valuable reference genome to the study of the avian genome evolution. In addition, the discovery of the genetic mechanism of white plumage not only is a breakthrough in the exploration of peafowl plumage, but also provides clues and new ideas for further investigations of the avian plumage coloration and artificial breeding in peafowl.