%0 Journal Article
%T Genomic Analysis Revealed a Convergent Evolution of LINE-1 in Coat Color: A Case Study in Water Buffaloes (Bubalus bubalis).
%A Liang D
%A Zhao P
%A Si J
%A Fang L
%A Pairo-Castineira E
%A Hu X
%A Xu Q
%A Hou Y
%A Gong Y
%A Liang Z
%A Tian B
%A Mao H
%A Yindee M
%A Faruque MO
%A Kongvongxay S
%A Khamphoumee S
%A Liu GE
%A Wu DD
%A Barker JSF
%A Han J
%A Zhang Y
%J Mol Biol Evol
%V 38
%N 3
%D 03 2021 9
%M 33212507
%F 8.8
%R 10.1093/molbev/msaa279
%X Visible pigmentation phenotypes can be used to explore the regulation of gene expression and the evolution of coat color patterns in animals. Here, we performed whole-genome and RNA sequencing and applied genome-wide association study, comparative population genomics and biological experiments to show that the 2,809-bp-long LINE-1 insertion in the ASIP (agouti signaling protein) gene is the causative mutation for the white coat phenotype in swamp buffalo (Bubalus bubalis). This LINE-1 insertion (3' truncated and containing only 5' UTR) functions as a strong proximal promoter that leads to a 10-fold increase in the transcription of ASIP in white buffalo skin. The 165 bp of 5' UTR transcribed from the LINE-1 is spliced into the first coding exon of ASIP, resulting in a chimeric transcript. The increased expression of ASIP prevents melanocyte maturation, leading to the absence of pigment in white buffalo skin and hairs. Phylogenetic analyses indicate that the white buffalo-specific ASIP allele originated from a recent genetic transposition event in swamp buffalo. Interestingly, as a similar LINE-1 insertion has been identified in the cattle ASIP gene, we discuss the convergent mechanism of coat color evolution in the Bovini tribe.