title: Identification and differential expression of microRNAs in ovaries of laying and Broody geese (Anser cygnoides) by Solexa sequencing.
abstract: BACKGROUND
  Recent functional studies have demonstrated that the microRNAs (miRNAs) play critical roles in ovarian gonadal development, steroidogenesis, apoptosis, and ovulation in mammals. However, little is known about the involvement of miRNAs in the ovarian function of fowl. The goose (Anas cygnoides) is a commercially important food that is cultivated widely in China but the goose industry has been hampered by high broodiness and poor egg laying performance, which are influenced by ovarian function.
  
  
  RESULTS
  In this study, the miRNA transcriptomes of ovaries from laying and broody geese were profiled using Solexa deep sequencing and bioinformatics was used to determine differential expression of the miRNAs. As a result, 11,350,396 and 9,890,887 clean reads were obtained in laying and broodiness goose, respectively, and 1,328 conserved known miRNAs and 22 novel potential miRNA candidates were identified. A total of 353 conserved microRNAs were significantly differentially expressed between laying and broody ovaries. Compared with miRNA expression in the laying ovary, 127 miRNAs were up-regulated and 126 miRNAs were down-regulated in the ovary of broody birds. A subset of the differentially expressed miRNAs (G-miR-320, G-miR-202, G-miR-146, and G-miR-143*) were validated using real-time quantitative PCR. In addition, 130,458 annotated mRNA transcripts were identified as putative target genes. Gene ontology annotation and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis suggested that the differentially expressed miRNAs are involved in ovarian function, including hormone secretion, reproduction processes and so on.
  
  
  CONCLUSIONS
  The present study provides the first global miRNA transcriptome data in A. cygnoides and identifies novel and known miRNAs that are differentially expressed between the ovaries of laying and broody geese. These findings contribute to our understanding of the functional involvement of miRNAs in the broody period of goose.
authors: Key Laboratory of Animal Genetics & Breeding and Molecular Design of Jiangsu province, Yangzhou University, Yangzhou, People's Republic of China.
authors: Qi
authors: Q
authors: Xu
authors: Key Laboratory of Animal Genetics & Breeding and Molecular Design of Jiangsu province, Yangzhou University, Yangzhou, People's Republic of China.
authors: Yang
authors: Y
authors: Zhang
authors: Key Laboratory of Animal Genetics & Breeding and Molecular Design of Jiangsu province, Yangzhou University, Yangzhou, People's Republic of China.
authors: Yang
authors: Y
authors: Chen
authors: Key Laboratory of Animal Genetics & Breeding and Molecular Design of Jiangsu province, Yangzhou University, Yangzhou, People's Republic of China.
authors: Yi-Yu
authors: YY
authors: Tong
authors: Key Laboratory of Animal Genetics & Breeding and Molecular Design of Jiangsu province, Yangzhou University, Yangzhou, People's Republic of China.
authors: Guang-Hui
authors: GH
authors: Rong
authors: Key Laboratory of Animal Genetics & Breeding and Molecular Design of Jiangsu province, Yangzhou University, Yangzhou, People's Republic of China.
authors: Zheng-Yang
authors: ZY
authors: Huang
authors: Jiangsu High Quality Poultry Engineering Technology Center, Changzhou, People's Republic of China.
authors: Rong-Xue
authors: RX
authors: Zhao
authors: Key Laboratory of Animal Genetics & Breeding and Molecular Design of Jiangsu province, Yangzhou University, Yangzhou, People's Republic of China.
authors: Wen-Ming
authors: WM
authors: Zhao
authors: Key Laboratory of Animal Genetics & Breeding and Molecular Design of Jiangsu province, Yangzhou University, Yangzhou, People's Republic of China.
authors: Xin-Sheng
authors: XS
authors: Wu
authors: Key Laboratory of Animal Genetics & Breeding and Molecular Design of Jiangsu province, Yangzhou University, Yangzhou, People's Republic of China.
authors: Guo-Bin
authors: GB
authors: Chang
authors: Key Laboratory of Animal Genetics & Breeding and Molecular Design of Jiangsu province, Yangzhou University, Yangzhou, People's Republic of China.
authors: Guo-Hong
authors: GH
authors: Chen
mesh_terms: D000818:Animals; D019295:Computational Biology; D005260:Female; D005777:Geese / Q000235:genetics*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D059014:High-Throughput Nucleotide Sequencing; D035683:MicroRNAs / Q000235:genetics*; D058977:Molecular Sequence Annotation; D009690:Nucleic Acid Conformation; D010053:Ovary / Q000378:metabolism*; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D015203:Reproducibility of Results
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger