title: Pedigree-based inbreeding coefficient explains more variation in fitness than heterozygosity at 160 microsatellites in a wild bird population.
abstract: Although the pedigree-based inbreeding coefficientFpredicts theexpectedproportion of an individual's genome that is identical-by-descent (IBD), heterozygosity at genetic markers captures Mendelian sampling variation and thereby provides an estimate ofrealizedIBD. Realized IBD should hence explain more variation in fitness than their pedigree-based expectations, but how many markers are required to achieve this in practice remains poorly understood. We use extensive pedigree and life-history data from an island population of song sparrows (Melospiza melodia) to show that the number of genetic markers and pedigree depth affected the explanatory power of heterozygosity andF, respectively, but that heterozygosity measured at 160 microsatellites did not explain more variation in fitness thanFThis is in contrast with other studies that found heterozygosity based on far fewer markers to explain more variation in fitness thanFThus, the relative performance of marker- and pedigree-based estimates of IBD depends on the quality of the pedigree, the number, variability and location of the markers employed, and the species-specific recombination landscape, and expectations based on detailed and deep pedigrees remain valuable until we can routinely afford genotyping hundreds of phenotyped wild individuals of genetic non-model species for thousands of genetic markers.
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland pirmin.nietlisbach@ieu.uzh.ch.
authors.forename: Pirmin
authors.identifier: http://orcid.org/0000-0002-6224-2246
authors.initials: P
authors.lastname: Nietlisbach
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Lukas F
authors.initials: LF
authors.lastname: Keller
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Glauco
authors.initials: G
authors.lastname: Camenisch
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Guillaume
authors.affiliation: Department of Forest and Conservation Sciences, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia, V6T 1Z4, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Arcese
authors.affiliation: Institute of Biological and Environmental Sciences, School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, UK.
authors.forename: Jane M
authors.identifier: http://orcid.org/0000-0002-5007-7343
authors.initials: JM
authors.lastname: Reid
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.|Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, Penryn TR10 9EZ, UK.
authors.forename: Erik
authors.identifier: http://orcid.org/0000-0003-0856-1294
authors.initials: E
authors.lastname: Postma
mesh_terms: D000818:Animals; D056084:Genetic Fitness; D005819:Genetic Markers; D005838:Genotype; D007178:Inbreeding; D018895:Microsatellite Repeats; D010375:Pedigree; D010641:Phenotype; D046370:Sparrows / Q000235:genetics*
chemical_list: D005819:Genetic Markers
keywords: Melospiza melodia; heterozygosity–fitness correlation; identity disequilibrium; inbreeding depression; short tandem repeats