title: The chicken frizzle feather is due to an α-keratin (KRT75) mutation that causes a defective rachis.
abstract: Feathers have complex forms and are an excellent model to study the development and evolution of morphologies. Existing chicken feather mutants are especially useful for identifying genetic determinants of feather formation. This study focused on the gene F, underlying the frizzle feather trait that has a characteristic curled feather rachis and barbs in domestic chickens. Our developmental biology studies identified defects in feather medulla formation, and physical studies revealed that the frizzle feather curls in a stepwise manner. The frizzle gene is transmitted in an autosomal incomplete dominant mode. A whole-genome linkage scan of five pedigrees with 2678 SNPs revealed association of the frizzle locus with a keratin gene-enriched region within the linkage group E22C19W28_E50C23. Sequence analyses of the keratin gene cluster identified a 69 bp in-frame deletion in a conserved region of KRT75, an α-keratin gene. Retroviral-mediated expression of the mutated F cDNA in the wild-type rectrix qualitatively changed the bending of the rachis with some features of frizzle feathers including irregular kinks, severe bending near their distal ends, and substantially higher variations among samples in comparison to normal feathers. These results confirmed KRT75 as the F gene. This study demonstrates the potential of our approach for identifying genetic determinants of feather forms.
authors: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.
authors: Chen Siang
authors: CS
authors: Ng
authors: Ping
authors: P
authors: Wu
authors: John
authors: J
authors: Foley
authors: Anne
authors: A
authors: Foley
authors: Merry-Lynn
authors: ML
authors: McDonald
authors: Wen-Tau
authors: WT
authors: Juan
authors: Chih-Jen
authors: CJ
authors: Huang
authors: Yu-Ting
authors: YT
authors: Lai
authors: Wen-Sui
authors: WS
authors: Lo
authors: Chih-Feng
authors: CF
authors: Chen
authors: Suzanne M
authors: SM
authors: Leal
authors: Huanmin
authors: H
authors: Zhang
authors: Randall B
authors: RB
authors: Widelitz
authors: Pragna I
authors: PI
authors: Patel
authors: Wen-Hsiung
authors: WH
authors: Li
authors: Cheng-Ming
authors: CM
authors: Chuong
mesh_terms: D000818:Animals; D001483:Base Sequence; D002645:Chickens / Q000033:anatomy & histology / Q000235:genetics; D005241:Feathers / Q000254:growth & development / Q000378:metabolism / Q000473:pathology; D018507:Gene Expression Regulation, Developmental; D008040:Genetic Linkage; D016678:Genome; D007633:Keratins / Q000235:genetics*; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D017384:Sequence Deletion
chemical_list: D007633:Keratins