A Phenol-Chloroform Protocol For Extracting GDNA From Egg Depleted Female Ticks

Abstract

By Thomas Brennan, Biological Sciences

Advisor: Joshua Benoit

Award: Excellence in Research Communication

Presentation ID: 209

Abstract: Ticks are blood feeding ectoparasites found on every continent. Despite their global presence these arthropods are relatively understudied. Developing methods for understand their biology is critical to understand and preventing tickborne diseases. Dermacentor albipictus is a species of tick native to North America primarily feeding on cervids. In this study, we have developed a working approach to extract genomic DNA (gDNA) from depleted D. albipictus females, which have blood fed, laid eggs, and expired. Isolating DNA from depleted female ticks allows for more efficient use of samples by allowing egg laying to study eggs and larvae. The negative aspects are the presence of host DNA from the blood meal and the poor body conditions of female ticks following egg laying. Here we tested several approaches for isolating gDNA from depleted female ticks. We address several complexities that make it difficult to isolate pure gDNA. We first tested extracting DNA from the whole body of the females, which resulted in high levels of host DNA mixed with tick DNA using a previously developed phenol-chloroform method. We also tested DNA isolations using the Qiagen DNeasy Blood & Tissue kit, however it resulted in unusable amounts of DNA. We found that a modified phenol-chloroform method of extracting from only the scutum and legs of female ticks resulted in the highest tick DNA purity and yield. This method of phenol-chloroform extraction provides a new tool for researchers to isolate DNA from arthropod samples that previously would have been considered unusable.