RESEARCH ARTICLE Construction, De-Novo Assembly and Analysis of Transcriptome for Identification of Reproduction-Related Genes and Pathways from Rohu, Labeo rohita

Rohu is a leading candidate species for freshwater aquaculture in South-East Asia. Unlike common carp the monsoon breeding habit of rohu restricts its seed production beyond sea-son indicating strong genetic control over spawning. Genetic information is limited in this regard. The problem is exacerbated by the lack of genomic-resources. We identified 182 reproduction-related genes previously by Sanger-sequencing which were less to address the issue of seasonal spawning behaviour of this important carp. Therefore, the present work was taken up to generate transcriptome profile by mRNAseq. 16GB, 72bp paired end (PE) data was generated from the pooled-RNA of twelve-tissues from pre-spawning rohu using IlluminaGA-II-platform. There were 64.97 million high-quality reads producing 62,283 contigs and 88,612 numbers of transcripts using velvet and oases programs, respectively. Gene ontology annotation identified 940 reproduction-related genes consisting of 184 mainly asso-ciated with reproduction, 223 related to hormone-activity and receptor-binding, 178 receptor-activity and 355 embryonic-development related-proteins. The important reproduction-rele-vant pathways found in KEGG analysis were GnRH-signaling, oocyte-meiosis, steroid-bio