Identification of differentially expressed known and novel miRNAs in broodiness of goose.

MicroRNAs (miRNAs) are endogenous small noncoding RNAs plays a critical role in posttranscriptional regulation of gene expression. Broodiness is observed in most avian species and influences egg production. Several genes are known to play an important role in regulating the progress of reproduction. The goose is one of the most important waterfowls. However, the involvement of miRNAs in the broodiness behavior of Anser cygnoides (Swan Goose) is unknown. High-throughput sequencing and bioinformatics analysis were used to identify the miRNAs involved in egg-laying and brooding behavior of geese in our study. The results showed 38 up-regulated and 14 down-regulated known miRNAs/miRNA*s with reads>1,000 in at least one group and a fold change of >2.0, compared with those of the egg-laying group (P<0.001). We also identified 114 and 94 novel miRNAs in the broody and egg-laying groups, respectively. Of these, 4 novel miRNAs were differentially expressed between the two groups. The study showed the expression of small RNAs in goose reproduction and identified known and novel miRNAs regulated in broodiness. The results reveal that these differentially expressed miRNAs may be involved in broodiness of A. cygnoides.