Molecular Biology and Evolution 17:1286-1293 (2000)
© 2000 Society for Molecular Biology and Evolution
Regular Article |
Evolutionary Diversification of Multigene Families: Allelic Selection of Toxins in Predatory Cone Snails
Department of Organismic and Evolutionary Biology, Biological Laboratories, Harvard University
Abstract
In order to investigate the evolution of conotoxin multigene families among two closely related vermivorous Conus species, we sequenced 104 four-loop conotoxin mRNAs from two individuals of Conus ebraeus and compared these with sequences already obtained from Conus abbreviatus. In contrast to the diversity of conotoxin sequences obtained from C. abbreviatus, only two common sequence variants were recovered from C. ebraeus. Segregation patterns of the variants in these two individuals and restriction digests of four-loop conotoxin amplification products from nine additional individuals suggest that the common variants are alleles from a single locus. These two putative alleles differ at nine positions that occur nonrandomly in the toxin-coding region of the sequences. Moreover, all substitutions are at nonsynonymous sites and are responsible for seven amino acid differences among the predicted amino acid sequences of the alleles. These results imply that conotoxin diversity is driven by strong diversifying selection and some form of frequency-dependent or overdominant selection at conotoxin loci, and they suggest that diverse conotoxin multigene families can originate from duplications at polymorphic loci. Furthermore, none of the sequences recovered from C. ebraeus appeared to be orthologs of loci from C. abbreviatus, and attempts to amplify orthologous sequences with locus-specific primers were unsuccessful among these species. These patterns suggest that venoms of closely related Conus species may differ due to the differential expression of conotoxin loci.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  S. M. Stanley Predation defeats competition on the seafloor Paleobiology, January 1, 2008; 34(1): 1 - 21. [Full Text] [PDF]
|
|
|
|
 |
|
 C. A. Palmer, R. A. Watts, R. G. Gregg, M. A. McCall, L. D. Houck, R. Highton, and S. J. Arnold Lineage-Specific Differences in Evolutionary Mode in a Salamander Courtship Pheromone Mol. Biol. Evol., November 1, 2005; 22(11): 2243 - 2256. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. A. Jakubowski, W. P. Kelley, J. V. Sweedler, W. F. Gilly, and J. R. Schulz Intraspecific variation of venom injected by fish-hunting Conus snails J. Exp. Biol., August 1, 2005; 208(15): 2873 - 2883. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. G. Bishop Directed Mutagenesis Confirms the Functional Importance of Positively Selected Sites in Polygalacturonase Inhibitor Protein Mol. Biol. Evol., July 1, 2005; 22(7): 1531 - 1534. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. Yang The power of phylogenetic comparison in revealing protein function PNAS, March 1, 2005; 102(9): 3179 - 3180. [Full Text] [PDF]
|
|
|
|
|
|
Z. Liu, J. I. B. Bos, M. Armstrong, S. C. Whisson, L. da Cunha, T. Torto-Alalibo, J. Win, A. O. Avrova, F. Wright, P. R. J. Birch, et al. Patterns of Diversifying Selection in the Phytotoxin-like scr74 Gene Family of Phytophthora infestans Mol. Biol. Evol., March 1, 2005; 22(3): 659 - 672. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. J. Clauss and T. Mitchell-Olds Functional Divergence in Tandemly Duplicated Arabidopsis thaliana Trypsin Inhibitor Genes Genetics, March 1, 2004; 166(3): 1419 - 1436. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Piontkivska, A. P. Rooney, and M. Nei Purifying Selection and Birth-and-death Evolution in the Histone H4 Gene Family Mol. Biol. Evol., May 1, 2002; 19(5): 689 - 697. [Abstract] [Full Text] [PDF]
|
|