Identification of genes related to beak deformity of chickens using digital gene expression profiling

PLoS One. 2014 Sep 8;9(9):e107050. doi: 10.1371/journal.pone.0107050. eCollection 2014.

Abstract

Frequencies of up to 3% of beak deformity (normally a crossed beak) occur in some indigenous chickens in China, such as and Beijing-You. Chickens with deformed beaks have reduced feed intake, growth rate, and abnormal behaviors. Beak deformity represents an economic as well as an animal welfare problem in the poultry industry. Because the genetic basis of beak deformity remains incompletely understood, the present study sought to identify important genes and metabolic pathways involved in this phenotype. Digital gene expression analysis was performed on deformed and normal beaks collected from Beijing-You chickens to detect global gene expression differences. A total of >11 million cDNA tags were sequenced, and 5,864,499 and 5,648,877 clean tags were obtained in the libraries of deformed and normal beaks, respectively. In total, 1,156 differentially expressed genes (DEG) were identified in the deformed beak with 409 being up-regulated and 747 down-regulated in the deformed beaks. qRT-PCR using eight genes was performed to verify the results of DGE profiling. Gene ontology (GO) analysis highlighted that genes of the keratin family on GGA25 were abundant among the DEGs. Pathway analysis showed that many DEGs were linked to the biosynthesis of unsaturated fatty acids and glycerolipid metabolism. Combining the analyses, 11 genes (MUC, LOC426217, BMP4, ACAA1, LPL, ALDH7A1, GLA, RETSAT, SDR16C5, WWOX, and MOGAT1) were highlighted as potential candidate genes for beak deformity in chickens. Some of these genes have been identified previously, while others have unknown function with respect to thus phenotype. To the best of our knowledge, this is the first genome-wide study to investigate the transcriptome differences in the deformed and normal beaks of chickens. The DEGs identified here are worthy of further functional characterization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Beak / pathology*
  • Biomarkers / metabolism*
  • Bird Diseases / genetics*
  • Bird Diseases / pathology
  • Chickens
  • China
  • Gene Expression Profiling*
  • Gene Ontology
  • Microarray Analysis / methods*
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Biomarkers
  • RNA, Messenger

Associated data

  • SRA/SRR1514178
  • SRA/SRR1514179

Grants and funding

This work was funded by 1. National High Technology Research and Development Program (863 Program)(2011AA100305,2008AA101009), National Natural Science Foundation of China. http://www.nsfc.gov.cn/; and 2. Agricultural Science and Technology Innovation Program (ASTIP-IAS04), Chinese Academy of Agricultural Sciences, China. http://www.caas.cn/en/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.