Comparative transcriptome analysis of the ovary and testis of the lacustrine goby (Gobiopterus lacustris)

ABSTRCTLacustrine goby (Gobiopterus lacustris) belongs to a genus of gobies that are small in size and endemic to freshwater, brackish waters or coastal environments around the Indian and Pacific oceans. To date, there are no genomic or transcriptomic studies on G. lacustris. Here, we constructed gonadal transcriptomes of G. lacustris for the first time and identified genes that may be involved in gonadal development and reproduction. In total, 60,657,644 and 52,016,136 clean reads were obtained from ovary and testis, respectively, using Illumina sequencing. Reads were assembled into 62,573 unigenes with N50 value of 3,082 bp and a mean length of 1,869 bp. A total of 47,891 (76.53%) unigenes were annotated in at least one of the seven databases that were used in this study. In addition, 38,550 SSRs (simple sequence repeat, microsatellite) were identified from 20,517 SSR containing sequences. Gene expression patterns in the testis and ovary were compared, and 10,954 DEGs (differentially expressed genes) were identified. Of these genes, 2,383 were up-regulated in the testis and 8,571 were up-regulated in the ovary. RT-qPCR analysis of 14 selected genes showed patterns consistent with the transcriptome results. Numerous DEGs involved in gonadal development and gametogenesis were identified, including foxl2, dmrt1, cyp19a1a, inha, inhb, sycp2, zglp1, tdrp, zps and esra. Using GO and KEGG enrichment analyses, pathways involving regulation of gonadal development and gametogenesis also identified. This work represents the first gonadal transcriptomic analysis of G. lacustris and provides a valuable dataset for future research on the genes involved in reproduction of G. lacustris.