Influences of multilocus heterozygosity on size during early life

Abstract

Genetic diversity has been hypothesized to promote fitness of individuals and populations, but few studies have examined how genetic diversity varies with ontogeny. We examined patterns in population and individual genetic diversity and the effect of genetic diversity on individual fitness among life stages (adults and juveniles) and populations of captive yellow perch (Perca flavescens) stocked into two ponds and allowed to spawn naturally. Significant genetic structure developed between adults and offspring in a single generation, even as heterozygosity and allelic richness remained relatively constant. Heterozygosity had no effect on adult growth or survival, but was significantly and consistently positively related to offspring length throughout the first year of life in one pond but not the other. The largest individuals in the pond exhibiting this positive relationship were more outbred than averaged size individuals and also more closely related to one another than they were to average-sized individuals, suggesting potential heritability of body size or spawn timing effects. These results indicate that the influence of heterozygosity may be mediated through an interaction, likely viability selection, between ontogeny and environment that is most important during early life. In addition, populations may experience significant genetic change within a single generation in captive environments, even when allowed to reproduce naturally.Accounting for the dynamic influences of genetic diversity on early life fitness could lead to improved understanding of recruitment and population dynamics in both wild and captive populations. K E Y W O R D Saquaculture, fish, heterozygosity-fitness correlation, microsatellite, Perca flavescens, relatedness

Genetic diversity of endangeredChondrostoma nasusin the River Rhine system: Conservation genetics considerations on stocking and reintroduction

“…Araki et al, 2007;Christie et al, 2012). In general, donor populations of high genetic variation are suitable for reintroduction of a species in lost parts of a species' range (Drauch et al, 2007;Forsman, 2014) since heterozygosity is often related to fitness (García-Navas et al, 2014;Feiner et al, 2017). Interbreeding of wild populations with hatchery fish that were hatchery-bred over multiple generations or are of a different gene pool may cause changes in the genetic structure of wild populations due to genetic drift, loss of genetic variability, reduced effective population size, outbreeding depression and general reduced fitness (e.g.…”