Identifying Species Divergence in the Endemic Caecidotea Cave Populations

Abstract

The Arbuckle karst system consists of caves, microfractures, and hydrogeologic barriers. Isopods in the genus Caecidotea inhabit the pools of water within the caves of the system. Young Caecidoteas travel through microfractures, and small populations move from one cave system to the next. Over the time these fractures close, causing the populations of Caecidotea to be isolated and potentially drift genetically. The sampled distinct populations have become morphologically distinct, but it is yet to be determined if they also have become genetically distinct species. DNA Barcoding using the Cytochrome Oxidase subunit 1 (COX1) gene will provide the percent of divergence in the samples obtained from different populations/locations. Successful DNA extraction is a pivotal part in this technique. A major obstacle addressed involves obtaining a high enough yield of DNA from the isopoda exoskeleton while keeping the extract clean from protein contamination. To address this, our lab has employed a variety of extraction procedures to optimize our DNA barcoding effort.