Genetics
Definitions
Allele - either of the two-paired genes, which affect an inheritable trait.
Amelanistic - having no melanin (Black Pigment)
Anerythristic - having no red color.
Axanthic - having no yellow color.
Codominant - a gene that causes the homozygous form to look different than the wild type and the heterozygous form to have traits of both.
DNA (Deoxyribonucleic Acid) - molecules bearing genetic information of all living cells.
Dominant - a gene that causes an animal to look different than the wild type and where the homozygous form and the heterozygous form look the same as each other.
Double Heterozygous - being heterozygous for two different traits.
Gene - unit of heredity that determines the characteristics of the offspring.
Genetics - the study of heredity.
Genotype – an organism’s genetic composition.
Heredity - the transmission of genetic characters from parents to offspring.
Het – an abbreviation for heterozygous.
Heterozygous – possessing two different genes for a given trait. An animal with one mutated, recessive gene still appears normal; its mutated gene can be inherited by future offspring. A Codominant animal is heterozygous for the dominant form of its mutated gene, yet is different in appearance than both the wild type and homozygous forms.
Homozygous – A state in which both genes for a specific trait are the same. When a recessive gene is it its homozygous form, it makes the animal look different from the wild type. When a dominant gene is in its homozygous state, it causes the animal to look different from both the wild type and the heterozygous (Codominant) forms.
Hypomelanistic - an animal having less black and/or brown color than a wild type.
Leucistic - a pure white animal with dark eyes.
Locus - a gene's position on a chromosome (plural: loci)
Melanin - black or brown skin pigments.
Melanistic - abnormally dark, especially due to an increase of melanin.
Mutation - an abnormal gene that under certain circumstances can cause an animal to be born with an appearance other than wild type.
Normal - an animal with no mutated genes - "wild type" in appearance.
Phenotype – an animal’s external appearance, as caused by its genotype.
Possible Het. - An animal from a known breeding that has either a 50% or 66% possibility of being "heterozygous" for a mutant gene.
- A 66% possible het comes from breeding 2 heterozygous animals together: 50% of the offspring are heterozygous, 25% will be homozygous, and 25% will be wild type. Of the normal appearing animals, 66% (or roughly 2 out of 3) will actually be heterozygous for the mutated gene.
- A 50% possible het comes from breeding a heterozygous animal to a wild-type animal. All of the resulting offspring will be wild type in appearance, but 50% of them will actually be heterozygous for the mutated gene and must be bred out to determine which animals are really hets.
Recessive - a gene that affects an animal's appearance if it's present in the homozygous state. A heterozygous animal carrying a mutated, recessive gene looks normal.
Super - commonly used herpetocultural term for the dominant form of a co-dominant mutation.
Wild type - the way the animal usually looks in nature (i.e. the normal color and pattern).
Xanthic - having more yellow color than wild type.
Morphs Explained
Albino - Albino Ball Pythons represent "amelanism" for their species. This genetic trait doesn't allow the body to produce "Melanin" (black pigment) resulting in a yellow and white animal. This trait is simple recessive (Tyrosinase -).
Axanthic - This gene represents "axanthism" in Ball Pythons. Axanthic Ball Pythons are typically "silver" and "black" as hatchlings. Axanthic Ball Pythons still have the ability to produce black and red pigments, which cause most of them to gain a "brownish" coloration as adults. This is a simple recessive trait.
Fire- Brightly colored, pale yellow snake. They have a kind of ghostly appearance, but the yellow is more intense. This is a Co-Dominant trait.
The super form of a Fire is called a Black Eyed Leustic.
Piebald- The Piebald gene produces a variable amount of white on the animal, which can cover hardly any or nearly all of the body. This is a simple recessive trait.
Lemon Pastel- These pastels have a lemon yellow coloration. This is a Co-Dominant trait.
Pastel- Yellow based coloration with a visible whitish hue on the head, they eyes are also have very light coloration. This is a Co-Dominant trait.
Spider- Very beautiful and extreme coloration and pattern. Distinct head pattern with an odd body pattern and splotches of white on the lower sides. This is a dominant trait.
Bumble Bee- Vivid yellow coloration with a deep black spider pattern, white splotches along the sides, and bright eyes. This is a designer morph, and is a Pastel Spider.
Mojave- Brown body coloration with golden lateral blotches, with a yellow cream colored filling in between the blotches. The lateral markings fade to almost a white, and the dorsal pattern is similar to a broken stripe. This is a Co-Dominant trait.
The super form of a Mojave is a Blue-Eyed Leustic.
Sugar
Caramel Albino- Butterscotch color, this is a form of albinism. This is a simple recessive trait (Tyrosinase +).
Normal- Wild type ball python
