A cis-regulatory mutation of PDSS2 causes silky-feather in chickens.

Chungang Feng,Jing Fei,Ning Li,Yiqiang Zhao,Yang Da,Hao Qu,Xiaoxiang Hu,Huifang Li,Ben Dorshorst,Qingyuan Li,Xiaorong Gu,Dingming Shu,Chi Song,Leif Andersson,Tongxin Liu,Yanqiang Wang,Carl-Johan Rubin,Jinxiu Li,Yu Tang Gao ,C M Ashwell ,Kuan-Wei Chen

doi:10.1371/journal.pgen.1004576

Abstract

Silky-feather has been selected and fixed in some breeds due to its unique appearance. This phenotype is caused by a single recessive gene (hookless, h). Here we map the silky-feather locus to chromosome 3 by linkage analysis and subsequently fine-map it to an 18.9 kb interval using the identical by descent (IBD) method. Further analysis reveals that a C to G transversion located upstream of the prenyl (decaprenyl) diphosphate synthase, subunit 2 (PDSS2) gene is causing silky-feather. All silky-feather birds are homozygous for the G allele. The silky-feather mutation significantly decreases the expression of PDSS2 during feather development in vivo. Consistent with the regulatory effect, the C to G transversion is shown to remarkably reduce PDSS2 promoter activity in vitro. We report a new example of feather structure variation associated with a spontaneous mutation and provide new insight into the PDSS2 function.

Highlights

The feather is one of the most complex integumentary appendages due to the extensive diversity in shape, size, arrangement and pigmentation, and is an excellent model for evolutionary and developmental biology as variations can occur at each step of development and differentiation
Well-studied natural variations in chicken include the BMP12 gene that changes the distribution of feathers on the neck (Naked neck trait) [3], the HOXC8 gene that changes the length of the cranial feathers (Crest trait) [4], and the KRT75 gene causing a characteristic curled feather rachis and barbs (Frizzle feather trait) [5]
The expression of the PDSS2 gene is decreased in silky-feather skin during feather development in vivo

Summary

Introduction

The feather is one of the most complex integumentary appendages due to the extensive diversity in shape, size, arrangement and pigmentation, and is an excellent model for evolutionary and developmental biology as variations can occur at each step of development and differentiation. A typical contour feather is composed of the calamus, rachis, barbs and afterfeathers. Feathers can develop into different types with part or all of the branching structures. Several feather types exist in the domesticated birds and these variations have been selectively bred. Variations in the structure, distribution, length, arrangement and number of feathers are widespread in chickens and pigeons [2]. Well-studied natural variations in chicken include the BMP12 gene that changes the distribution of feathers on the neck (Naked neck trait) [3], the HOXC8 gene that changes the length of the cranial feathers (Crest trait) [4], and the KRT75 gene causing a characteristic curled feather rachis and barbs (Frizzle feather trait) [5]

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Discussion

Conclusion