How do you calculate the expected heterozygosity of multiple alleles?
Expected heterozygosity (Hexp = 2pq) for a 2-allele system as a function of allele frequency, p. Note that the heterozygosity peaks at a value of 0.5, when the allele frequencies are equal (p=q).
How do you determine the number of heterozygotes?
Answer: The frequency of heterozygous individuals is equal to 2pq. In this case, 2pq equals 0.32, which means that the frequency of individuals heterozygous for this gene is equal to 32% (i.e. 2 (0.8)(0.2) = 0.32).
Does heterozygosity vary with population size?
Looking at these equations it is clear that with small population sizes, heterozygosity will be lost quickly (drift will proceed quickly), whereas in large populations there will be little loss of heterozygosity. becomes a bit different from every other deme, the variation among demes increases.
Can a locus have more than 2 alleles?
Alleles are the pairs of genes occupying a specific spot called locus on a chromosome. Typically, there are only two alleles for a gene in a diploid organism. When there is a gene existing in more than two allelic forms, this condition is referred to as multiple allelism.
What heterozygosity means?
Heterozygous is a state of having inherited different forms of a particular gene from each one of your biological parents. Now, by different forms we generally mean that there are different portions of the gene where the sequence is different.
What is expected heterozygosity?
The gene diversity of a locus, also known as its expected heterozygosity (H), is a fundamental measure of genetic variation in a population, and describes the proportion of heterozygous genotypes expected under Hardy-Weinberg equilibrium (Nei 1973).
What causes heterozygosity?
But at each gene locus associated with the disease, there is the possibility of compound heterozygosity, often caused by inheritance of two unrelated alleles, of which one is a common or classic mutation, while the other is a rare or even novel one.
What is the difference between a homozygote and heterozygote?
Homozygous: You inherit the same version of the gene from each parent, so you have two matching genes. Heterozygous: You inherit a different version of a gene from each parent.
How is heterozygosity related to the study of genetic variation?
Heterozygosity—the condition of having two different alleles at a locus—is fundamental to the study of genetic variation in populations. Indeed, Mendel’s original work was based on tracing the transmission to progeny of the two alleles present in heterozygous individuals at individual loci or combinations of loci.
How many breeding females are needed for heterozygosity?
Approximately 1000 breeding females were used to perpetuate each colony during the first 12 laboratory generations, and during this time there was actually a slight increase in heterozygosity at the MDH (malate dehydrogenase) genetic locus in each colony.
Do you subtract heterozygosity from the total?
If we want the heterozygosity, we just subtract that from the total. With just two alleles it isn’t as efficient to calculate the heterozygosity by the “one minus the homozygosity route”. Consider the case, though, of a locus with 6 alleles.
When is the heterozygosity of a two allele system greatest?
Say p = q = 0.5. The heterozygosity for a two-allele system is described by a concave down parabola that starts at zero (when p = 0) goes to a maximum at p = 0.5 and goes back to zero when p = 1. In fact, for any multi-allelic system, heterozygosity is greatest when