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 similarity of the expression patterns of conopeptides across individuals of each species was evaluated using the ten most highly expressed conopeptides as reference (supplementary tables S7 and S8, Supplementary Material online). It was found that of the ten most highly expressed conopeptides in each specimen of C. tribblei, seven conopeptides were common among all individuals whereas other highly expressed conopeptides were observed in one or two specimens only (fig. 8a). Likewise, six of the ten most highly expressed conopeptides in each C. lenavati individual were similar in all three individuals whereas the other most highly expressed conopeptides were different among specimens of C. lenavati (fig. 8b). The presence of a combination of highly expressed conopeptides that are common in all individuals and other conopeptides which are highly expressed in one or two specimens resulted in a distinct set of highly expressed conopeptides in each individual (fig. 8 and supplementary tables S7 and S8, Supplementary Material online). The majority of the highly expressed conopeptides in both species belonged to superfamilies and groups (O1, O2, B2, P, con-ikot-ikot, and G-like) with high expression levels (fig. 2b). Notably, conopeptides of several superfamilies such as O3, M, T, and U were among the highly expressed conopeptide in individuals of C. lenavati but not in C. tribblei (fig. 8 and supplementary tables S7 and S8, Supplementary Material online). Similarly, one H-superfamily conopeptide was highly expressed only in the individuals of C. tribblei. Interestingly, six of the ten highly expressed conopeptides in the individuals of C. tribblei and C. lenavati were orthologous conopeptide pairs identified between these species (fig. 8).Fig. 8.—
Affiliation: Marine Science Institute, University of the Philippines-Diliman, Quezon City, Philippines.