Identification and characterization of microRNAs and Piwi-interacting RNAs in cockerels' sperm by Solexa sequencing

There have been substantial researches focused on the roles of microRNAs (miRNA) and Piwi-interacting RNAs (piRNA) delivered from mammalian spermatozoa, comparatively little is known about the role of sperm-delivered miRNAs and piRNAs within cockerels' (breeding cock) sperm. A small RNA library of cockerels' sperm was constructed using Illumine high-throughput sequencing technology. Overall design: A small RNA library of cockerels' sperm was constructed using Illumine high-throughput sequencing technology. Unique sequences with lengths of 18-26 nucleotides were mapped to miRBase 21.0 and unique sequences with lengths of 25-37 nucleotides were mapped to piRNA database. A total of 1,311 miRNAs and 2,448 potential piRNAs were identified. Based on stem-loop qRT-PCR, eight miRNAs were validated.