Comparison of the Venom Peptides and Their Expression in Closely Related Conus Species: Insights into Adaptive Post-speciation Evolution of Conus Exogenomes.
Bottom Line: In this study, the sequences and expression levels of conotoxins from several specimens of two closely related worm-hunting species, Conus tribblei and Conus lenavati, were compared through transcriptome analysis.Comparison of the interspecific expression patterns of conopeptides at the superfamily level resulted in the discovery of both conserved as well as species-specific expression patterns, indicating divergence in the regulatory network affecting conotoxin gene expression.Comparison of the transcriptomes of the individual snails revealed that each specimen produces a distinct set of highly expressed conopeptides, reflecting the capability of individual snails to fine-tune the composition of their venoms.
Affiliation: Marine Science Institute, University of the Philippines-Diliman, Quezon City, Philippines.Show MeSH
Mentions: The conopeptides with identical mature regions belonged to 14 superfamilies (B1-, N-, O1-, O2-, P-, W- and Y-superfamilies, “divergent MKFPLLFISL” superfamily, con-ikot-ikot and conopressin/conophysin families, and A-like, Y2-like, SF-02 and SF-04 groups) (fig. 6a). The expression levels of all orthologous conopeptide gene pairs in C. tribblei and C. lenavati were moderately correlated (r = 0.640, P value < 0.001, data not shown), and the correlation of the expression of identical orthologous conopeptide genes was slightly lower (r = 0.614, P = 0.003) (fig. 6a). Notably, the expressions of three outliers (conopeptides of O1- and O2- and P-superfamilies) (fig. 6a) in the correlation test of identical orthologs were highly divergent that upon their exclusion, the correlation increased to r = 0.924 (P value < 0.001). The expression of orthologs having higher rate of dS to dN was moderately though not significantly correlated (r = 0.749, P = 0.02) (fig. 6b), whereas the expression of orthologous pairs under positive selection showed weak correlation (r = 0.585, P value < 0.001) (fig. 6c).Fig. 6.—
Affiliation: Marine Science Institute, University of the Philippines-Diliman, Quezon City, Philippines.