085 -- Developing Resources for Assessing Genetic Diversity in a Non-native Ant-mimicking Spider

The ant-mimicking spider Myrmarachne formicaria (Salticidae) is a species native to Eurasia and was first identified in North America in 2001. It has since been found in many locations in the Northeast including New York, Pennsylvania, Ohio, Ontario, and more recently as far as Chicago. Little is known about its introduction to North America and how it has dispersed since. By characterizing the mitochondrial and nuclear genetic diversity of this species, we can learn about its introduction history and dispersal patterns. Previous sequencing of two mitochondrial genes, CO1 and ND1, from 27 specimens collected from 14 localities in New York, Pennsylvania, and Ohio yielded no genetic polymorphisms. Comparisons with sequence data in GenBank for other salticid species have shown that within-species divergence in the mitochondrial DNA ND1 region is found in other spiders, so M. formicaria’s lack of variation is likely unusual. The nuclear ribosomal ITS2 gene region was also sequenced but gave ambiguous results suggesting the need for more specific primers. Our current data are consistent with a single invasion of M. formicaria from one source locality, but data from additional loci and samples would help to confirm this conclusion. Our research is shifting to RNA sequencing to discover more informative gene regions for comparison. We are fine-tuning methods for extracting high-quality RNA from M. formicaria and a related non-mimic spider. By analyzing RNA sequence data, we can identify genes that harbor more genetic variation or discover single sequence repeats useful for population genetics analysis.