title: Quantitative effect of a CNV on a morphological trait in chickens.
abstract: Copy Number Variation has been associated with morphological traits, developmental defects or disease susceptibility. The autosomal dominant Pea-comb mutation in chickens is due to the massive amplification of a CNV in intron 1 of SOX5 and provides a unique opportunity to assess the effect of variation in the number of repeats on quantitative traits such as comb size and comb mass in Pea-comb chickens. The quantitative variation of comb size was estimated by 2D morphometry and the number of repeats (RQ) was estimated by qPCR, in a total of 178 chickens from 3 experimental lines, two of them showing segregation for the Pea-comb mutation. This study included only Pea-comb chickens. Analysis of variance showed highly significant effects of line and sex on comb measurements. Adult body weight (BW) and RQ were handled as covariates. BW significantly influenced comb mass but not comb size. RQ values significantly influenced comb size, and the linear regression coefficient was highest for heterozygous carriers: the higher the number of repeats, the smaller the comb size. A similar trend was observed for comb mass. The CNV contributed to 3.4% of the phenotypic variance of comb size in heterozygous carriers of the CNV, an order of magnitude frequently encountered for QTLs. Surprisingly, there was no such relationship between RQ values and comb size in the homozygous line. It may be concluded that heterozygosity for a CNV in a non-coding region may contribute to phenotypic plasticity.
authors.affiliation: Institut National de la Recherche Agronomique, AgroParisTech, UMR1313 Animal Genetics and Integrative Biology, Jouy-en-Josas, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Moro
authors.affiliation: Museum National d'Histoire naturelle, UMR 7205 Institut de Systématique, Évolution, Biodiversité, 57 rue Cuvier, Paris, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Cornette
authors.affiliation: Institut National de la Recherche Agronomique, AgroParisTech, UMR1313 Animal Genetics and Integrative Biology, Jouy-en-Josas, France.
authors.forename: Agathe
authors.initials: A
authors.lastname: Vieaud
authors.affiliation: Institut National de la Recherche Agronomique, AgroParisTech, UMR1313 Animal Genetics and Integrative Biology, Jouy-en-Josas, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bruneau
authors.affiliation: Institut National de la Recherche Agronomique, UE1295 Pôle d'Expérimentation Avicole de Tours, Nouzilly, France.
authors.forename: David
authors.initials: D
authors.lastname: Gourichon
authors.affiliation: Institut National de la Recherche Agronomique, AgroParisTech, UMR1313 Animal Genetics and Integrative Biology, Jouy-en-Josas, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Bed'hom
authors.affiliation: Institut National de la Recherche Agronomique, AgroParisTech, UMR1313 Animal Genetics and Integrative Biology, Jouy-en-Josas, France.
authors.forename: Michèle
authors.initials: M
authors.lastname: Tixier-Boichard
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002645:Chickens / Q000033:anatomy & histology / Q000235:genetics*; D056915:DNA Copy Number Variations; D005260:Female; D008297:Male; D009154:Mutation; D010641:Phenotype; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D055755:SOXD Transcription Factors / Q000235:genetics
chemical_list: D055755:SOXD Transcription Factors