[POLAR WHITES]

Examples of Simple Inheritance

First Cross

If a pure breeding Cinnamon male is mated to pure breeding Golden female, the resulting pups are all golden. Why is this?

The Cinnamon allele, (p), is recessive to its wild type counterpart, (P). Since both animals are pure breeding, (homozygous), each has two copies of one allele at the Cinnamon locus. The Cinnamon hamster will have two Cinnamon alleles, listed as pp. The Golden hamster will have two wild type alleles, (PP).

When the Golden female makes eggs she will "send" one chromosome of each pair to each egg. Since she has the allele E at both of her Cinnamon loci, all of her eggs will receive a chromosome with the allele P on it. By a similar deduction, all the Cinnamon male's sperm cells will contain only the allele p. When these gametes fuse to form an embryo hamster the genetic makeup that it will inherit is Pp.



p from sperm p from sperm
P from egg Pp Pp
P from egg Pp Pp

The wild type allele, (P),is dominant, so this is what is shown in the youngsters' appearance. This generation from the first crossing are called the First Filial generation, (F1). It is important to note that the young F1 hamsters, although they resemble their mother, are not homozygous, (pure breeding), like her. They have two different alleles at their cinnamon locus. They are described as heterozygous, although breeders would tend to describe them more simply as "carrying Cinnamon", or "being split for Cinnamon". Although it cannot be seen, the Cinnamon allele, (p), is in the makeup of these hamsters, inherited from their father.

Let us imagine that from the litter of young hamsters, a male and a female are kept and bred from.

also there can be long haired and short haired in the same litter if one of the parents is long haired or carries the long haired gene, but the long haired gene is recessive so it needs to copies