title: Copy number variants in locally raised Chinese chicken genomes determined using array comparative genomic hybridization.
abstract: BACKGROUND
  Copy number variants contribute to genetic variation in birds. Analyses of copy number variants in chicken breeds had focused primarily on those from commercial varieties with nothing known about the occurrence and diversity of copy number variants in locally raised Chinese chicken breeds. To address this deficiency, we characterized copy number variants in 11 chicken breeds and compared the variation among these breeds.
  
  
  RESULTS
  We presented a detailed analysis of the copy number variants in locally raised Chinese chicken breeds identified using a customized comparative genomic hybridization array. We identified 833 copy number variants contained within 308 copy number variant regions. The median and mean sizes of the copy number variant regions were 14.6 kb and 35.1 kb, respectively. Of the copy number variant regions, 138 (45%) involved gain of DNA, 159 (52%) involved loss of DNA, and 11 (3%) involved both gain and loss of DNA. Principal component analysis and agglomerative hierarchical clustering revealed the close relatedness of the four locally raised chicken breeds, Shek-Ki, Langshan, Qingyuan partridge, and Wenchang. Biological process enrichment analysis of the copy number variant regions confirmed the greater variation among the four aforementioned varieties than among the seven other breeds studied.
  
  
  CONCLUSIONS
  Our description of the distribution of the copy number variants and comparison of the differences among the copy number variant regions of the 11 chicken breeds supplemented the information available concerning the copy number variants of other Chinese chicken breeds. In addition to its relevance for functional analysis, our results provided the first insight into how chicken breeds can be clustered on the basis of their genomic copy number variation.
authors.forename: Ming
authors.initials: M
authors.lastname: Tian
authors.forename: Yanqiang
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Gu
authors.forename: Chungang
authors.initials: C
authors.lastname: Feng
authors.forename: Suyun
authors.initials: S
authors.lastname: Fang
authors.forename: Xiaoxiang
authors.initials: X
authors.lastname: Hu
authors.forename: Ning
authors.initials: N
authors.lastname: Li
mesh_terms: D000818:Animals; D001947:Breeding; D002645:Chickens / Q000145:classification / Q000235:genetics*; D002681:China; D002874:Chromosome Mapping; D016000:Cluster Analysis; D055028:Comparative Genomic Hybridization; D056915:DNA Copy Number Variations; D005260:Female; D016678:Genome; D008297:Male; D058977:Molecular Sequence Annotation; D025341:Principal Component Analysis