How do you calculate genome heterozygosity?

Recently, Wang et al. (2015) defined a genome-wide measure of heterozygosity as the ratio of the number of heterozygous SNPs divided by the number of nonreference homozygous SNPs. We refer to this normalized measure of heterozygosity as the heterozygosity ratio.

How is COI calculated?

We calculate the inbreeding coefficient of Kirri by multiplying the risk of getting an allele from each parent and then halving that value as Kirri is another generation away from Winna. Therefore the inbreeding coefficient of Kirri is (½ x ½ x ½) X (½ x ½ x ½) / 2 = 1/26 / 2 = 0.0078125 = 0.78%.

How are inbreeding and selection against heterozygotes related?

Inbreeding tends to reduce diversity within populations (but may increase diversity, or at least the variance, among populations). In a complete selfing population, the number of heterozygotes at any given locus decreases.

Is inbred homozygous or heterozygous?

This explanation is intuitively appealing as inbred individuals are expected to be relatively homozygous throughout the genome. However, the inbreeding coefficient and MLH do not measure the same quantity. When two alleles at a locus are ibd, the genotype is said to be autozygous, otherwise the genotype is allozygous.

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.

Why is loss of heterozygosity bad?

Loss of heterozygosity (LOH) refers to a specific type of genetic mutation during which there is a loss of one normal copy of a gene or a group of genes. In some cases, loss of heterozygosity can contribute to the development of cancer.

What is a good COI?

So, in terms of health, a COI less than 5% is definitely best. Above that, there are detrimental effects and risks, and the breeder needs to weigh these against whatever benefit is expected to gained. Inbreeding levels of 5-10% will have modest detrimental effects on the offspring.

What is a major disadvantage of inbreeding?

What is a major disadvantage of inbreeding? Inbreeding is detrimental to reproductive performance and preweaning and postweaning growth. They are also most susceptible to environmental stresses. Quickly identifies serious recessive genes.

Why are inbred babies deformed?

Inbreeding increases the risk of recessive gene disorders Inbreeding also increases the risk of disorders caused by recessive genes. These disorders can lead to calf abnormalities, miscarriages and stillbirths. Animals must have two copies of a recessive gene to have the disorder.

How to calculate heterozygosity for a single locus?

The simplest way to calculate it for a single locus is as: Eqn 4.1 where piis the frequency of the ithof kalleles. [Note that p1, p2, p3etc. may correspond to what you would normally think of as p, q, r, setc.]. If we want the gene diversity over several loci, we need double summation and subscripting as follows: Eqn 4.2

What is the expected probability of heterozygosity?

Here is a way that I like to think of heterozygosity (HEor D). It is the (expected) probability that an individual will be heterozygous at a given locus (or over the assayed loci for a multi-locus system). For many human microsatellite loci, for example, HEis often > 0.85, meaning that you have a > 85% chance of being a heterozygote.

How many homozygotes and heterozygostes are there?

It has 21 possible genotypes — 6 kinds of homozygotes and 15 kinds of heterozygotes. Writing it out, 6 + 5 + 4 + 3 + 2 + 1 = 21 = [6*(6+1)]/2 — this is the formula for combinations of six things taken two at a time, order unimportant — [n(n+1)] / 2.

Why is heterozygosity lower than expected under Hardy Weinberg equilibrium?

Low heterozygosity means little genetic variability. Often, we will compare the observed level of heterozygosity to what we expect under Hardy-Weinberg equilibrium (HWE). If the observed heterozygosity is lower than expected, we seek to attribute the discrepancy to forces such as inbreeding.