Pedigree-based inbreeding coefficient explains more variation in fitness than heterozygosity at 160 microsatellites in a wild bird population.
Proceedings of the Royal Society B: Biological Sciences
© 2017 The Author(s) Published by the Royal Society. All rights reserved.
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.
Our work was supported by Swiss National Science Foundation grants (31003A-116794 to L.F.K., PP00P3_144846 to F.G.), Natural Sciences and Engineering Research Council of Canada grants to P.A., and grants by the Forschungskredit of the University of Zurich (FK-15-104), Georges und Antoine Claraz-Schenkung and Dr Joachim de Giacomi foundation to P.N.
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.
Vol. 284: 20162763.
Place of publication