Influence of immune-relevant genes on mate choice and reproductive success in wild-spawning hatchery-reared and wild-born coho salmon (Oncorhynchus kisutch)

摘要

Hatcheries support fisheries and aid in the recovery of endangered wild populations. Evidence for reduced reproductive success (RS) in wild-spawning hatchery-reared salmon compared with that in wild-born fish invites questions about the impact on subsequent generations. Immune gene-dependent mate preference is one mechanism known to influence salmonid fitness. We evaluated mate choice and correlates of RS to better understand fitness differences between hatchery-reared and wild-born fish using a previously constructed genetic pedigree of coho salmon (Onchorhynchus kisutch) from the Umpqua River, Oregon. Two years (2005 and 2006) of three wild-spawning mate pair classes were examined: wild x wild (W x W), hatchery x hatchery (H x H), and wild x hatchery (W x H). We found no evidence for mate choice within mate pair classes based on microsatellites linked to the major histocompatibility complex (MHC) and immune-relevant expressed sequence tags. Greater W x W mate pair RS was associated with increased MHC diversity in 2005 and 2006, while greater W x H mate pair RS was correlated to intermediate MHC diversity in 2006. We found no correlation between MHC diversity and H x H mate pair RS. Our results suggest that greater MHC diversity between wild-born coho pairs may increase offspring survival