RUI: Evolutionary and ecological impacts of horizontal gene transfer in arthropods

Spelman College, Atlanta GA

Investigators

Abstract

How organisms acquire new traits is a central question in evolutionary biology. We know that new traits can arise from mutations and other types of changes to existing genes and chromosomes. However, prokaryotes, such as bacteria, are also able to acquire completely new genetic information and traits from other bacteria or from their environment through a process known as horizontal gene transfer (HGT). These horizontally transferred genes can allow bacteria to rapidly adapt to new environments. Until recently, it was thought that HGT happened only in bacteria. However, multiple apparent cases of HGT have been documented in a wide range of organisms, including the fungi, plants, and animals. The goal of this project is to identify, validate, and characterize HGTs in multiple blood-feeding and plant-eating arthropod species, including two species of ecologically and economically important mites. Results will expand our understanding of how widespread HGT is in eukaryotes and how it has contributed to their evolution, diversification, and ability to take advantage of new environments. The research will take place at Spelman College, an historically black all-women's college. Female minority undergraduate students will collaborate on the project and receive hands-on research training. A teaching and research post-doctoral fellow will also be trained. Outreach includes the development of educational materials for middle and high school students, and a half-day teacher training event. This project seeks to determine whether HGTs played a role in the acquisition of convergent phenotypic traits necessary for the invasion of novel niches by divergent arthropod species. The researchers will validate, characterize, and curate previously identified HGTs in arthropods and determine the prevalence and extent of shared HGTs, using a standardized methodology. The researchers hypothesize that HGT has repeatedly allowed for the independent acquisition of similar novel phenotypic traits in multiple distantly related arthropod species, and has allowed for niche invasion and novel resource exploitation in these species. A combination of bioinformatic, transcriptomic, and genomic approaches will be used to identify and validate HGTs across 15 arthropod species. Resulting data will be used to test the prediction that HGTs are shared by multiple niche-sharing species, either blood-feeders or herbivores, while being absent from more closely related, but non-niche sharing species.