title: Genomic organization, transcriptomic analysis, and functional characterization of avian α- and β-keratins in diverse feather forms.
abstract: Feathers are hallmark avian integument appendages, although they were also present on theropods. They are composed of flexible corneous materials made of α- and β-keratins, but their genomic organization and their functional roles in feathers have not been well studied. First, we made an exhaustive search of α- and β-keratin genes in the new chicken genome assembly (Galgal4). Then, using transcriptomic analysis, we studied α- and β-keratin gene expression patterns in five types of feather epidermis. The expression patterns of β-keratin genes were different in different feather types, whereas those of α-keratin genes were less variable. In addition, we obtained extensive α- and β-keratin mRNA in situ hybridization data, showing that α-keratins and β-keratins are preferentially expressed in different parts of the feather components. Together, our data suggest that feather morphological and structural diversity can largely be attributed to differential combinations of α- and β-keratin genes in different intrafeather regions and/or feather types from different body parts. The expression profiles provide new insights into the evolutionary origin and diversification of feathers. Finally, functional analysis using mutant chicken keratin forms based on those found in the human α-keratin mutation database led to abnormal phenotypes. This demonstrates that the chicken can be a convenient model for studying the molecular biology of human keratin-based diseases.
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan cmchuong@med.usc.edu whli@gate.sinica.edu.tw.
authors.forename: Chen Siang
authors.initials: CS
authors.lastname: Ng
authors.affiliation: Department of Pathology, Keck School of Medicine, University of Southern California cmchuong@med.usc.edu whli@gate.sinica.edu.tw.
authors.forename: Ping
authors.initials: P
authors.lastname: Wu
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.
authors.forename: Wen-Lang
authors.initials: WL
authors.lastname: Fan
authors.affiliation: Department of Pathology, Keck School of Medicine, University of Southern California Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yan
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan Institute of Ecology and Evolutionary Biology, National Taiwan University, Taipei, Taiwan.
authors.forename: Chih-Kuan
authors.initials: CK
authors.lastname: Chen
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Lai
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.
authors.forename: Siao-Man
authors.initials: SM
authors.lastname: Wu
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan Molecular Biology of Agricultural Sciences, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Chi-Tang
authors.initials: CT
authors.lastname: Mao
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Chen
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.
authors.forename: Mei-Yeh Jade
authors.initials: MY
authors.lastname: Lu
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.
authors.forename: Meng-Ru
authors.initials: MR
authors.lastname: Ho
authors.affiliation: Department of Pathology, Keck School of Medicine, University of Southern California.
authors.forename: Randall B
authors.initials: RB
authors.lastname: Widelitz
authors.affiliation: Department of Animal Science, National Chung Hsing University, Taichung, Taiwan Center for the Integrative and Evolutionary Galliformes Genomics (iEGG Center), National Chung Hsing University, Taichung, Taiwan.
authors.forename: Chih-Feng
authors.initials: CF
authors.lastname: Chen
authors.affiliation: Department of Pathology, Keck School of Medicine, University of Southern California Center for the Integrative and Evolutionary Galliformes Genomics (iEGG Center), National Chung Hsing University, Taichung, Taiwan cmchuong@med.usc.edu whli@gate.sinica.edu.tw.
authors.forename: Cheng-Ming
authors.initials: CM
authors.lastname: Chuong
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei, Taiwan Department of Ecology and Evolution, University of Chicago cmchuong@med.usc.edu whli@gate.sinica.edu.tw.
authors.forename: Wen-Hsiung
authors.initials: WH
authors.lastname: Li
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000235:genetics* / Q000378:metabolism; D002645:Chickens / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D019143:Evolution, Molecular; D005241:Feathers / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D020869:Gene Expression Profiling; D023281:Genomics; D006801:Humans; D007633:Keratins / Q000235:genetics* / Q000378:metabolism; D005810:Multigene Family; D010802:Phylogeny; D053800:beta-Keratins / Q000235:genetics* / Q000378:metabolism
chemical_list: D030161:Avian Proteins; D053800:beta-Keratins; D007633:Keratins
keywords: RNA-seq; chicken; evolution; feather; in situ hybridization; keratin; skin appendage; transcriptome; zebra finch