Linked genes
3. If genes at certain loci tend to be inherited together, then we speak of linked genes. Genes are mostly linked when their loci are near each other on the same chromosome. Indeed, if the loci are linked, during meiosis, recombination gametes and non-recombination gametes are produced according to the recombination frequency, which corresponds to the distance between genes
Let's illustrate this phenomenon
When we mate 1 homozygous animal to a heterozygous animal for two different genes, |
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if the loci are independent, each parent produces the expected germ cells: | |
Therefore, in the offspring, we expect: |
However, if the two loci are linked, the heterozygous parent does not produce 50% AB and 50% ab germ cells. Therefore, in the offspring we can't expect 50%AABB and 50% AaBb.
