Estimating Relatedness in the Presence of Null Alleles.
Studies of genetics and ecology often require estimates of relatedness coefficients based on genetic marker data. However, with the presence of null alleles, an observed genotype can represent one of several possible true genotypes. This results in biased estimates of relatedness. As the numbers of marker loci are often limited, loci with null alleles cannot be abandoned without substantial loss of statistical power. Here, we show how loci with null alleles can be incorporated into six estimators of relatedness (two novel). We evaluate the performance of various estimators before and after correction for null alleles. If the frequency of a null allele is <0.1, some estimators can be used directly without adjustment; if it is >0.5, the potency of estimation is too low and such a locus should be excluded. We make available a software package entitled PolyRelatedness v1.6, which enables researchers to optimize these estimators to best fit a particular data set.
Shaanxi Key Laboratory for Animal Conservation, and College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China.
Kang
K
Huang
Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
Kermit
K
Ritland
Shaanxi Key Laboratory for Animal Conservation, and College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China.
Derek W
DW
Dunn
Shaanxi Key Laboratory for Animal Conservation, and College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China.
Xiaoguang
X
Qi
Shaanxi Key Laboratory for Animal Conservation, and College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China.
Songtao
S
Guo
Shaanxi Key Laboratory for Animal Conservation, and College of Life Sciences, Northwest University, Xi'an, Shaanxi 710069, China baoguoli@nwu.edu.cn.
Baoguo
http://orcid.org/0000-0002-8357-117X
B
Li
D000483:Alleles; D005819:Genetic Markers; D005821:Genetic Techniques; D005838:Genotype; D008957:Models, Genetic; D012984:Software
D005819:Genetic Markers
maximum likelihood; method-of-moment; null alleles; relatedness coefficient