RESUMO
The swimming crab Portunus trituberculatus is a commercially important crab species in East Asia countries. Gonadal development is a physiological process of great significance to the reproduction as well as commercial seed production for P. trituberculatus. However, little is currently known about the molecular mechanisms governing the developmental processes of gonads in this species. To open avenues of molecular research on P. trituberculatus gonadal development, Illumina paired-end sequencing technology was employed to develop deep-coverage transcriptome sequencing data for its gonads. Illumina sequencing generated 58,429,148 and 70,474,978 high-quality reads from the ovary and testis cDNA library, respectively. All these reads were assembled into 54,960 unigenes with an average sequence length of 879 bp, of which 12,340 unigenes (22.45% of the total) matched sequences in GenBank non-redundant database. Based on our transcriptome analysis as well as published literature, a number of candidate genes potentially involved in the regulation of gonadal development of P. trituberculatus were identified, such as FAOMeT, mPRγ, PGMRC1, PGDS, PGER4, 3ß-HSD and 17ß-HSDs. Differential expression analysis generated 5,919 differentially expressed genes between ovary and testis, among which many genes related to gametogenesis and several genes previously reported to be critical in differentiation and development of gonads were found, including Foxl2, Wnt4, Fst, Fem-1 and Sox9. Furthermore, 28,534 SSRs and 111,646 high-quality SNPs were identified in this transcriptome dataset. This work represents the first transcriptome analysis of P. trituberculatus gonads using the next generation sequencing technology and provides a valuable dataset for understanding molecular mechanisms controlling development of gonads and facilitating future investigation of reproductive biology in this species. The molecular markers obtained in this study will provide a fundamental basis for population genetics and functional genomics in P. trituberculatus and other closely related species.
Assuntos
Braquiúros/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica no Desenvolvimento , Ovário/metabolismo , Análise de Sequência de RNA/métodos , Testículo/metabolismo , Animais , Feminino , Ontologia Genética , Estudos de Associação Genética , Marcadores Genéticos , Masculino , Repetições de Microssatélites/genética , Anotação de Sequência Molecular , Motivos de Nucleotídeos/genética , Polimorfismo de Nucleotídeo Único/genética , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Especificidade da Espécie , Transcriptoma/genéticaRESUMO
Based on the EST sequence from a hemocyte cDNA library, the cathepsin L cDNA of Exopalaemon carinicauda (EcCatL) was cloned by rapid amplification of cDNA ends (RACE). The EcCatL cDNA was 1136 bp in length, which contains an open reading frame (ORF) of 960 bp, encoding a 319 amino-acid polypeptide. Homology analysis revealed that the amino acid sequence of EcCatL was highly conserved with its homologs in other crustaceans. The similarities of EcCatL with the CatL of Palaemonetes varians and Pandalus borealis were 92% and 76%, respectively. Phylogenetic analysis showed that EcCatL was in the same branch as that of Palaemonetes varians. The expression levels of EcCatL in different tissues were analyzed by quantitative real-time PCR. Expression of EcCatL was detected in all tested tissues of E. carinicauda, including hemocytes, gill, hepatopancreas, muscle, ovary, intestine, stomach and eyestalk, with the highest expression level in hepatopancreas. After challenged with Vibrio anguillarum or white spot syndrome virus, the expression of EcCatL were up-regulated in the hemocytes and hepatopancreas of E. carinicauda. Our results implied that EcCatL might play an important role in the prawn immune response.