Neutral variation does not predict immunogenetic variation in the European grayling (Thymallus thymallus) - implications for management

Preservation of genetic diversity is critical to successful conservation and there is increasing demand for the inclusion of ecologically meaningful genetic information in management decisions. Supportive breeding programmes are increasingly implemented to combat declines in many species, yet their effect on adaptive genetic variation is understudied. This is despite the fact that supportive breeding may interfere with natural evolutionary processes. Here, we assessed the performance of neutral and adaptive markers (Major Histocompatibility Complex; MHC) to inform management of European grayling (Thymallus thymallus), which routinely involves supplementation of natural populations with hatchery-reared fish (stocking). This study is the first to characterize MH II DAA and DAB loci in grayling and to investigate immune genetic variation in relation to management practice in this species. High-throughput Illumina sequencing of ‘introduced’, ‘stocked native’ and ‘non-stocked native’ populat...