Stronghold Reptiles

A Small Hands On Breeder

Genetics

Genetics 101. The easy version

Here are a few definitions to get you started:

Gene: A sequence of chemicals in DNA or RNA that determine the transmission of certain traits to offspring.

Mutation: A change in a gene that causes an inheritable trait to change.

Morph: A word genetic variation.

Trait: An inheritable characteristic such as skin color or pattern.

Allele: (Pronounced A-leel) Either of the 2 paired genes (one from the mother and one from the father) that determine inherited characteristics. Alleles are usually represented as letters with a capital letter being dominant and a lowercase letter being recessive.

Homozygous: Fully showing a genetic trait. It has 2 identical Alleles for that trait

Heterozygous: 2 different Alleles for a trait. Abbreviated het.

Wild Type Showing no sign of a genetic trait or also called a normal. It has 2 identical alleles. Abbreviated WT.

Dominant trait: A type of trait in which the homozygous form and the heterozygous form look the same.

Co-Dominant trait: A type of trait in which the heterozygous form looks different from both the Homozygous and Wild Type:

Recessive trait: A type of trait in which the heterozygous form looks the same as the wild type.

The first step is figuring out what kind of trait it is: Dominant, Co-dominant, or Recessive. There are two ways you can go about doing this. You could breed an animal that shows the trait with an animal that does not and then breed the children together and collect all you data. Then you would have to compare the percentages of the offspring that show the trait with the statistics that I am going to give you in a bit. This method requires years of hard work and meticulous record keeping. Or you can just do your homework and find out from the people who have already done this hard work for you what type of trait you are looking at.

One of the easiest traits to play with here is albinism. In Ball Pythons, albino animals are missing the chemicals in their skin that produce black pigment. Albinism is a recessive trait so we know that if you breed an albino to a wild type or normal, you are going to get 100% heterozygous offspring.

A Punnett Square is an easy way to show what alleles the offspring are going to have. Go to this link to view the punnet squares in use:

http://ballpython.com/page.php?topic=genetically2