title: Effective number of breeders from sibship reconstruction: empirical evaluations using hatchery steelhead.
abstract: Effective population size (Ne) is among the most important metrics in evolutionary biology. In natural populations, it is often difficult to collect adequate demographic data to calculateNedirectly. Consequently, genetic methods to estimateNehave been developed. TwoNeestimators based on sibship reconstruction using multilocus genotype data have been developed in recent years: sibship assignment and parentage analysis without parents. In this study, we evaluated the accuracy of sibship reconstruction using a large empirical dataset from five hatchery steelhead populations with known pedigrees and using 95 single nucleotide polymorphism (SNP) markers. We challenged the software COLONY with 2,599,961 known relationships and demonstrated that reconstruction of full-sib and unrelated pairs was greater than 95% and 99% accurate, respectively. However, reconstruction of half-sib pairs was poor (<5% accurate). Despite poor half-sib reconstruction, both estimators provided accurate estimates of the effective number of breeders (Nb) when sample sizes were near or greater than the trueNband when assuming a monogamous mating system. We further demonstrated that both methods provide roughly equivalent estimates ofNb. Our results indicate that sibship reconstruction and current SNP panels provide promise for estimatingNbin steelhead populations in the region.
authors.affiliation: Idaho Department of Fish and Game/Pacific States Marine Fisheries Commission Eagle Fish Genetics Lab Eagle ID USA; Present address: Michael W. Ackerman, Quantitative Consultants, Inc.705 S 8th St.Boise ID 83702 USA.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Ackerman
authors.affiliation: Flathead Lake Biological Station Division of Biological Sciences University of Montana Polson MT USA.
authors.forename: Brian K
authors.initials: BK
authors.lastname: Hand
authors.affiliation: School of Aquatic and Fishery Sciences University of Washington Seattle WA USA.
authors.forename: Ryan K
authors.initials: RK
authors.lastname: Waples
authors.affiliation: Flathead Lake Biological Station Division of Biological Sciences University of Montana Polson MT USA.
authors.forename: Gordon
authors.initials: G
authors.lastname: Luikart
authors.affiliation: NOAA Fisheries Northwest Fisheries Science Center Seattle WA USA.
authors.forename: Robin S
authors.initials: RS
authors.lastname: Waples
authors.affiliation: Idaho Department of Fish and Game/Pacific States Marine Fisheries Commission Eagle Fish Genetics Lab Eagle ID USA.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Steele
authors.affiliation: Flathead Lake Biological Station Division of Biological Sciences University of Montana Polson MT USA.
authors.forename: Brittany A
authors.initials: BA
authors.lastname: Garner
authors.affiliation: Idaho Department of Fish and Game/Pacific States Marine Fisheries Commission Eagle Fish Genetics Lab Eagle ID USA.
authors.forename: Jesse
authors.initials: J
authors.lastname: McCane
authors.affiliation: Idaho Department of Fish and Game Eagle Fish Genetics Lab Eagle ID USA.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Campbell
keywords: COLONY; Oncorhynchus mykiss; PwoP; conservation genetics; effective population size; genetic monitoring; sibship assignment; sibship reconstruction