Meeting Abstract
P2.185 Monday, Jan. 5 Quantification of biotransformation enzymes implicated in Neotoma lepida’s ability to consume creoste NEBEKER, CA*; SKOPEC, MM; HALEY, S; DEARING, MD; Weber State University; Weber State University; University of Utah; University of Utah cneb45@yahoo.com
Two populations of the desert woodrat (Neotoma lepida) have different tolerances for creosote bush (Larrea tridentata). Very few animals consume creosote bush since the leaves are coated with a toxic phenolic resin deterring herbivory. However, a population of the desert woodrat from the Mojave Desert consumes creosote as a large part of its diet; leading us to believe it has evolved a superior ability to biotransform the resin present on creosote bush when compared to a population of the desert woodrat from the Great Basin desert where creosote bush is absent. A previous study in the lab showed that the Mojave woodrats have higher activity of two detoxification enzymes glutathione s-transferase (GST) and cytochrome P450 2B (CYP2B) compared to Great Basin woodrats when fed a diet containing creosote resin as well as a control diet. We quantified the amount of enzyme present using western blots,and found that similar to enzyme activity, there was a trend for GST protein levels to be higher in the Mojave woodrats than the Great Basin woodrats when fed a diet containing creosote resin as well as a control diet (F3,20=2.363 p=0.102). For CYP2B however, their was no difference in the amount of protein between the two populations (F3,20=0.225 p=0.878) . This leads us to assume the Mojave population has evolved a new isoform of CYP2B that is more effective and therefore has higher activity per unit protein. Our next step is to compare the gene sequences for CYP2B in both populations to determine if they differ in a manner that could lead to functional differences.
