Bioinformatics Analysis of Protein Coding Genes Associated with Cold Tolerance Phenotypes in Animals: Implications for Assessing Adaptation of Invasive Reptile Species

Reptiles represent an understudied clade of animals for which unique physiological properties confer adaptive phenotypes that are sometimes distinct from those observed in mammals. Cold tolerance phenotypes have been reported in numerous animals including mammals, birds, amphibians, reptiles and fish. A variety of molecular and cellular adaptations confer cold tolerance survival phenotypes (e.g. freeze tolerance, freeze avoidance and cryoprotective dehydration; cryoprotectant transport of water; anoxia/ischemia tolerance; metabolic rate modulation) under freezing temperatures. We performed a comparative genomics based bioinformatics analysis of proteins associated with these phenotypes among a variety of species. Our results provide a genomic framework for understanding how combinations of genes contribute to adaptive traits associated with species survival in extreme environments. Furthermore, our work sheds light on possible genetic mechanisms underlying aspects of species-specific climate induced geographical range boundaries. In light of climate change concerns, some invasive reptiles, such as the Burmese python, are expected to exhibit expanded host ranges. However, mutations within regions of the genome encoding proteins associated with cold tolerant phenotypes may provide an alternative mechanism for expanded range. Through a systematic investigation of invasive species’ genomic diversity, it may be possible to develop genetic tools that can be used to identify and characterize early shifts in fitness associated with the potential for enhanced cold tolerance phenotypes. Such genetic resources offer objective and quantitative measures for assessing risk of invasive reptile expanded geographic range.