The Mediterranean scorpion Mesobuthus gibbosus (Scorpiones, Buthidae): transcriptome analysis and organization of the genome encoding chlorotoxin-like peptides

作者：Diego Garcia Elia; Caliskan Figen; Tytgat Jan^*

来源：BMC Genomics, 2014, 15(1): 295.

DOI：10.1186/1471-2164-15-295

• Scorpion transcriptome
• Chlorotoxin
• Genomic organization
• Mesobuthus gibbosus
• Venom glands
• Scorpion toxin

Background: Transcriptome approaches have revealed a diversity of venom compounds from a number of venomous species. Mesobuthus gibbosus scorpion showed a medical importance for the toxic effect of its sting. Previously, our group reported the first three transcripts that encode toxin genes in M. gibbosus. However, no additional toxin genes or venom components have been described for this species. Furthermore, only a very small number of reports on the genomic organization of toxin genes of scorpion species have been published. Up to this moment, no information on the gene characterization of M. gibbosus is available.
Results: This study provides the first insight into gene expression in venom glands from M. gibbosus scorpion. A cDNA library was generated from the venom glands and subsequently analyzed (301 clones). Sequences from 177 high-quality ESTs were grouped as 48 Mgib sequences, of those 48 sequences, 40 (29 "singletons" and 11 "contigs") correspond with one or more ESTs. We identified putative precursor sequences and were grouped them in different categories (39 unique transcripts, one with alternative reading frames), resulting in the identification of 12 new toxin-like and 5 antimicrobial precursors (transcripts). The analysis of the gene families revealed several new components categorized among various toxin families with effect on ion channels. Sequence analysis of a new KTx precursor provides evidence to validate a new KTx subfamily (alpha-KTx 27.x). A second part of this work involves the genomic organization of three Meg chlorotoxin like genes (ClTxs). Genomic DNA sequence reveals close similarities (presence of one same-phase intron) with the sole genomic organization of chlorotoxins ever reported (from M. martensii).
Conclusions: Transcriptome analysis is a powerful strategy that provides complete information of the gene expression and molecular diversity of the venom glands (telson). In this work, we generated the first catalogue of the gene expression and genomic organization of toxins from M. gibbosus. Our result represents a relevant contribution to the knowledge of toxin transcripts and complementary information related with other cell function proteins and venom peptide transcripts. The genomic organization of the chlorotoxin genes may help to understand the diversity of this gene family.

• 出版日期2014-4-21