Abstract

The Crest mutation in chicken shows incomplete dominance and causes a spectacular phenotype in which the small feathers normally present on the head are replaced by much larger feathers normally present only in dorsal skin. Using whole-genome sequencing, we show that the crest phenotype is caused by a 197 bp duplication of an evolutionarily conserved sequence located in the intron of HOXC10 on chromosome 33. A diagnostic test showed that the duplication was present in all 54 crested chickens representing eight breeds and absent from all 433 non-crested chickens representing 214 populations. The mutation causes ectopic expression of at least five closely linked HOXC genes, including HOXC10, in cranial skin of crested chickens. The result is consistent with the interpretation that the crest feathers are caused by an altered body region identity. The upregulated HOXC gene expression is expanded to skull tissue of Polish chickens showing a large crest often associated with cerebral hernia, but not in Silkie chickens characterized by a small crest, both homozygous for the duplication. Thus, the 197 bp duplication is required for the development of a large crest and susceptibility to cerebral hernia because only crested chicken show this malformation. However, this mutation is not sufficient to cause herniation because this malformation is not present in breeds with a small crest, like Silkie chickens.

Keywords

crest; skin regional specificity; cerebral hernia; IBD mapping; HOXC gene cluster

Published in

G3
2021, Volume: 11, number: 2, article number: jkaa048
Publisher: OXFORD UNIV PRESS INC

SLU Authors

• Andersson, Leif

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    
  • Texas A&M University
  • Uppsala University

UKÄ Subject classification

Animal and Dairy Science


More information

Correction in: G3, 2022, Volume 12, Issue 2, Article number jkab425, DOI 10.1093/g3journal/jkab425


Publication identifier

DOI: https://doi.org/10.1093/g3journal/jkaa048

Permanent link to this page (URI)

https://res.slu.se/id/publ/112273