Testes transcriptome profiles of the anadromous fish Coilia nasus during the onset of spermatogenesis.

RNA-Seq technology has been widely applied to transcriptomics, genomics and functional gene study. Here, we performed de novo transcriptome sequencing to produce 23,842,172 clean reads representing a total of 4,815,798,404 (4.8 Gb) nucleotides from comprehensive transcript dataset for testis of Coilia nasus. Over 20 million Illumina reads were assembled into 194,636 unigenes, and 42,642 annotated genes were predicted by Blastx and ESTScan, respectively. Applying Blast analysis and functional annotation (e.g., GO, COG, SwissProt and KEGG) using the assembled gene models from catalogs of other species, we have sampled an extensive and diverse expressed gene catalog for C. nasus representing a large proportion of the genes involved in the onset of spermatogenesis. The results will provide a general clue to the potential spermatogenesis molecular mechanisms for this species.