P-like conotoxins detected in Turris babylonia

Allan  L. Hilario,; Francisco  M. Heralde Iii,

P-like conotoxins detected in Turris babylonia

Allan L. Hilario | Francisco M. Heralde Iii

Abstract:

Toxin homologs are common across turrid species and reflect on similarities of their prey types. P-like conotoxin is one type isolated in various turrid snails, which exhibits conserved sequences in their precursor peptides with marked diversity and subtype variations in similar groups of turrid snails, a toxin repertoire patterning, termed as “P-coding” system, employed by turrid snails as a toxin diversification strategy to better target their prey. This study aimed to determine if P-like type 1 and type 3 conotoxin genes are present in Turris babylonia using gene-specific primers used in Gemmula species. Total RNA was extracted from venom duct and then used to prepare double-stranded (ds) cDNA. The ds cDNA was used as template for P-like type 1 and type 3 conotoxins amplification. Then, the amplicons generated were sent to Macrogen, Inc., Seoul, South Korea for sequencing and analyzed using DNAsis. Results showed that P-like conotoxin type 1 and type 3 were amplified from T. babylonia. The gene sequences showed similar framework IX scaffold. The P-like conotoxin type 1 has 85 amino acid residues with the characteristic six-cysteine residues and a conserve region of YEDGE similar to T. babylonia. The P-like conotoxin type 3 is the first of this type ever reported in this gastropod species. It has 62 amino acid residues with six-cysteine residues but with divergent amino acid sequence from the P-like type 1 conotoxin. Plike conotoxin type 1 and 3 were detected in T. babylonia using gene specific primers for Gemmula species. The detection of theseP-like conotoxins provides support on the hypothesis of a possible “P-coding” systemamong the turrid snails.Similar approach can be done in other turrid species.

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