Document Type
Article
Original Publication Date
2007
Journal/Book/Conference Title
BMC Evolutionary Biology
Volume
7
DOI of Original Publication
10.1186/1471-2148-7-175
Date of Submission
September 2014
Abstract
Background
Snake venom composition varies widely both among closely related species and within the same species, based on ecological variables. In terrestrial snakes, such variation has been proposed to be due to snakes' diet. Land snakes target various prey species including insects (arthropods), lizards (reptiles), frogs and toads (amphibians), birds (aves), and rodents (mammals), whereas sea snakes target a single vertebrate class (fishes) and often specialize on specific types of fish. It is therefore interesting to examine the evolution of toxins in sea snake venoms compared to that of land snakes.
Results
Here we describe the expression of toxin genes in the venom glands of two sea snakes, Lapemis curtus (Spine-bellied Sea Snake) and Acalyptophis peronii (Horned Sea Snake), two members of a large adaptive radiation which occupy very different ecological niches. We constructed cDNA libraries from their venom glands and sequenced 214 and 192 clones, respectively. Our data show that despite their explosive evolutionary radiation, there is very little variability in the three-finger toxin (3FTx) as well as the phospholipase A2 (PLA2) enzymes, the two main constituents of Lapemis curtusand Acalyptophis peronii venom. To understand the evolutionary trends among land snakes, sea snakes and sea kraits, pairwise genetic distances (intraspecific and interspecific) of 3FTx and PLA2sequences were calculated. Results show that these proteins appear to be highly conserved in sea snakes in contrast to land snakes or sea kraits, despite their extremely divergent and adaptive ecological radiation.
Conclusion
Based on these results, we suggest that streamlining in habitat and diet in sea snakes has possibly kept their toxin genes conserved, suggesting the idea that prey composition and diet breadth may contribute to the diversity and evolution of venom components.
Rights
© 2007 Pahari et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Is Part Of
VCU Biochemistry and Molecular Biology Publications
Calculation of genetic distance for 3FTx and the PLA2 enzymes. The data compares genetic distances among land snakes, sea snakes and sea kraits.
Comments
Originally published at http://dx.doi.org/10.1186/1471-2148-7-175