Correlation-based inference for linkage disequilibrium with multiple alleles.

The correlation between alleles at a pair of genetic loci is a measure of linkage disequilibrium. The square of the sample correlation multiplied by sample size provides the usual test statistic for the hypothesis of no disequilibrium for loci with two alleles and this relation has proved useful for study design and marker selection. Nevertheless, this relation holds only in a diallelic case, and an extension to multiple alleles has not been made.

Nb_HetEx: a program to estimate the effective number of breeders.

The program "Nb_HetEx" estimates the effective number of breeders (N(b)) that produced the sampled progeny based on genotype counts contained in that sample. When the number of breeders is very small, there is an excess of heterozygotes in their progeny: the smaller the number of breeders, the larger the heterozygote excess. The Nb_HetEx program also estimates N(e) through the temporal method.

[Macrogeographic genetic variability in the gastropod mollusk Littorina sitkana from the northwest Pacific].

Variation at four highly polymorphic allozyme loci (inorganic pyrophosphatase, peptidase, and two esterase loci) was examined in 25 settlements of the marine snail Littorina sitkana (Mollusca, Gastropoda). The sampling localities covered a wide part of the species range: from the Peter the Great Bay (the Sea of Japan) at the southwest to the Mednyi Island (Commander Islands) at the northeast. Like other littorines lacking the pelagic stage, L.

[Genetically dispersed effective population size determined by mitochondrial genes].

A formula for variance effective population size (Ne) for analysis of mitochondrial genes is deduced and discussed. Only the female part of the population is taken into account; hence, Ne is, in the given case, the effective number of females. Ne = m2(N - 1)/sigma 2, where N is the number of females, sigma 2 is the variance of the reproductive contributions of individual females (measured as the number of their daughters that are part of the next generation), and m is the mean number of daughters per female.