Hemocytes transcriptome profile of the Chinese mitten crab (Eriocheir sinensis)

Abstract

The Chinese mitten crab (Eriocheir sinensis) possesses an open circulatory system, in which hemolymph moves through interconnected sinuses or spaces surrounding organs called hemocoels. The hemocytes are classified into hyalinocytes, semigranulocytes, and granulocytes; and limited transcriptomics research is available. In this study, the transcriptome of the crab E. sinensis hemocytes was characterized. A total of 14,380,229 clean reads representing a total of 4.31 Gb nucleotides dataset were produced. A total of 67,047 contigs were obtained and 12.49% (8375) and 9.74% (6533) of the contigs were matched to data publicly available from the GenBank nr nucleotide and Uniprot databases, respectively. Among these contigs, 4344 contigs belong to three categories of Gene Ontology, 126 contigs to 21 subcategories of KEGG, and 4962 contigs to 25 categories of the COG database. A total of 508,379 and 345 transcripts of the E. sinensis showed >40% sequence similarity with transcripts expressed in the vertebrate blood cells from tilapia (Oreochromis niloticus), Chinese softshell turtle (Trionyx sinensis) and chicken (Gallus gallus) respectively. A total of 53,077 single nucleotide polymorphisms were identified and 9912 SSRs for microsatellite mining were found. The most frequent repeat motifs detected were dinucleotide repeats, accounting for 37.52% of the total repeats. Our data provides an important gene resource for the exploitation of molecular marker-assisted breeding, immune mechanisms and conservation of germplasm in the crab E. sinensis.