title: Sib-parentage testing using molecular markers when parents are unknown.
abstract: The formulae for computing the so-called Sib Index using codominant alleles for (1) full-sib and (2) half-sib parentage are given. Hypothesis testing is based on the distribution of conditional likelihood ratio or Bayes' factor. Thresholds for rejecting the null hypothesis and P-values were obtained in function of the number of alleles and their frequency distributions. Simulations showed that a relatively low number of marker systems (e.g. 20) are enough to accept the hypothesis of sib parentage with a reasonable power for usual significance levels, but that a higher number would be necessary if full-sib against half-sib parentage is the contrast to be carried out. The effect of sampling variation on the allele frequencies on power calculations is also analysed.
mesh_terms: D000483:Alleles; D000818:Animals; D001947:Breeding; D004285:Dogs / Q000235:genetics; D005260:Female; D005819:Genetic Markers; D005838:Genotype; D016013:Likelihood Functions; D008297:Male; D008957:Models, Genetic
chemical_list: D005819:Genetic Markers