Moving into a New Era: Lahontan Cutthroat Trout and Next Gen Sequencing

Lahontan cutthroat trout (Oncorhynchus clarkii henshawi, LCT), listed as threatened under the United States Endangered Species Act, has been extirpated from > 90% of its historical range.  Endemic to the hydrographic Lahontan basin in the northern Great Basin desert, this subspecies historically persisted in this highly variable and harsh environment by living in large interconnected multiple order stream and lake systems.  As a result, it was once the largest cutthroat trout ever documented, and has an unusual tolerance for the high salinity and temperatures of the desert terminal lakes and streams of the Basin. The impending impacts of global climate change have increased efforts to characterize genetic variation in adaptive traits, especially temperature tolerance.  Earlier work has shown that temperature tolerance is a heritable trait in this subspecies and experimental evidence shows considerable variation among known family groups.  Next generation sequencing of these same family groups will allow us to identify SNPs associated with this trait. Analysis of LCT populations from range-wide temperature extremes  –  as well as cutthroat-rainbow trout hybrids – will also allow us to characterize SNP polymorphisms that may indicate adaptation to differing environments and will be useful in determining management priorities for this sub-species.