Transcriptome Analysis Of The Venom Gland Of The Chinese Spider Macrothele Raveni

The spider, Macrothele ravani, located in guangxi province of china, is a new specie of spinning spider. This spider mainly hunts insects. Its venom is a complex mixture of small molecules, peptides and large proteins. In forward to cloning more toxin-encoding genes, finding the mainingful peptides with medicinal prospects, we have constructed a directed full length cDNA library of the venom gland of the spider Macrothele ravani. The titer of the cDNA library is 1.0 × 106 cfu/ml, in which one clone of the low-abundance messenger RNA can be found. Through random sequencing,492 expressed sequence tags (ESTs) were collected. By cluster analysis,43 contigs, containing two or more ESTs, and 112 single sequences, containing only one EST were yielded. Though bioinformatic analysis, among the 492 ESTs,303 ESTs (62%) encode toxin-like peptides,49 ESTs encode body proteins, and 140 ESTs have no hits with the NCBI databases. There are 114 unique toxin-encoding precuesors containing 68 mature peptides. Based on the sequences similarity and disulfide bond arrangement, these precursors are divided into 14 superfamilies (superfamily I-XIV). The functions of these peptides were analyzed based on bioinformatic analysis. This study provides a base for the subsequent physiological research of peptide toxins from the spider Macrothele ravani. We also annotate the gene ontology of the non-toxin compotents of the ESTs in the cDNA library.