The Rise and Fall of an Evolutionary Innovation: Contrasting Strategies of Venom Evolution in Ancient and Young Animals
It is shown that the venoms of ancient lineages remarkably evolve under the heavy constraints of negative selection, while toxin families in lineages that originated relatively recently rapidly diversify under the influence of positive selection.
Evolution of separate predation- and defence-evoked venoms in carnivorous cone snails
It is proposed that defensive toxins, originally evolved in ancestral worm-hunting cone snails to protect against cephalopod and fish predation, have been repurposed in predatory venoms to facilitate diversification to fish and mollusk diets.
A panel of microsatellites to individually identify leopards and its application to leopard monitoring in human dominated landscapes
- S. Mondol, N. R, V. Athreya, K. Sunagar, V. Selvaraj, U. Ramakrishnan
- Environmental ScienceBMC Genetics
- 4 December 2009
A DNA-based method for leopard individual identification where fecal DNA samples are used to obtain genetic material and the selected panel of eight microsatellite loci can conclusively identify leopards from various kinds of biological samples is described.
Evolution Stings: The Origin and Diversification of Scorpion Toxin Peptide Scaffolds
It is demonstrated that even neglected lineages of scorpions are a rich pool of novel biochemical components, which have evolved over millions of years to target specific ion channels in prey animals, and as a result, possess tremendous implications in therapeutics.
Intraspecific venom variation in the medically significant Southern Pacific Rattlesnake (Crotalus oreganus helleri): biodiscovery, clinical and evolutionary implications.
Three-Fingered RAVERs: Rapid Accumulation of Variations in Exposed Residues of Snake Venom Toxins
- K. Sunagar, Timothy N. W. Jackson, E. Undheim, S. A. Ali, A. Antunes, B. Fry
- 1 November 2013
It is shown that Type I, II and III α-neurotoxins have evolved with extreme rapidity under the influence of positive selection and a theory of Rapid Accumulation of Variations in Exposed Residues (RAVER) to illustrate the significance of point mutations, guided by focal mutagenesis and positive selection in the evolution and diversification of 3FTx.
Evolution of an ancient venom: recognition of a novel family of cnidarian toxins and the common evolutionary origin of sodium and potassium neurotoxins in sea anemone.
It is shown that despite long evolutionary histories, most cnidarian toxins remain conserved under the strong influence of negative selection, a finding that is in striking contrast to the rapid evolution of toxin families in evolutionarily younger lineages, such as cone snails and advanced snakes.
Ecological venomics: How genomics, transcriptomics and proteomics can shed new light on the ecology and evolution of venom.
Widespread convergence in toxin resistance by predictable molecular evolution
- B. Ujvari, N. Casewell, T. Madsen
- BiologyProceedings of the National Academy of Sciences
- 8 September 2015
Evidence of constrained convergent molecular evolution across the metazoan tree of life is provided by showing that resistance to toxic cardiac glycosides produced by plants and bufonid toads is mediated by similar molecular changes to the sodium-potassium-pump in insects, amphibians, reptiles, and mammals.
Evolution of CRISPs associated with toxicoferan-reptilian venom and mammalian reproduction.
- K. Sunagar, W. Johnson, S. O’Brien, V. Vasconcelos, A. Antunes
- BiologyMolecular biology and evolution
- 1 February 2012
The use of ancestral sequence reconstruction, mapping of mutations on the three-dimensional structure, and detailed evaluation of selection pressures suggests that the toxicoferan CRISPs underwent accelerated evolution aided by strong positive selection and directional mutagenesis, whereas their mammalian homologs are constrained by negative selection.