Isolation of the methionine sulfoxide reductase B3 (MSRB3) gene from the red-eared slider, Trachemys scripta elegans

Oxidative stress from reactive oxygen species (ROS) is hypothesized to be a primary cause of aging and aging-related diseases. For my thesis research, my advisor and I examined adaptation to oxidative stress in the red-eared slider, Trachemys scripta elegans, a turtle that goes long periods with low oxygen during hibernation, but then quickly re-acclimates to higher oxygen levels upon surfacing. This dramatic ischemia/reperfusion event should result in ROS formation, but the turtle appears to reduce oxidative stress. We aimed to isolate the gene for methionine sulfoxide reductase B3, a protein that alleviates oxidative stress by reconverting oxygen damaged methionine-R-sulfoxide to the amino acid methionine. We designed degenerate primers to amplify a conserved region of the MSRB gene to isolate a partial DNA sequence. We then used 5’ RACE PCR and vectorette library PCR to isolate much of the coding region of the gene from T. scripta.