Article: It's All About the Morphs
Color and pattern mutations can produce some spectacular animals
In recent years, captive breeding of reptiles with color and pattern mutations has resulted in a cornucopia of incredible looking animals. By combining different mutations, brilliantly colored animals have been produced that look like nothing ever found in nature. These mutations can sell for large amounts of money, and can be big business.
In this article, I will go over some of the basics, so beginners can become more familiar with the genetics of these amazing animals.
There are three primary types of mutations found in reptiles. They aren't the only types of mutations involved, but they are the most easily understood and common.
Every animal that is born or hatched contains two sets of genes--one set from each parent. If an animal has only one copy of a mutant gene (one parent passed on a mutant gene, but the other passed on a normal gene), it is said to be heterozygous for that mutant trait. If the animal has two copies of a mutant gene (both parents passed on the mutant gene), then it is said to be homozygous for that trait.
Dominant mutation: The mutant gene is dominant, and it is expressed (shows up outwardly in the animal), while the normal gene is suppressed (doesn't show up). If the animal receives only one copy of the gene from one parent, and a normal gene from the other parent, it will look like a mutant. If the animal receives one copy of the mutant gene from each parent (2 copies) it will look exactly the same as if it had only one copy.
Recessive mutation: The mutant gene is recessive, and if a normal gene is present, the mutant gene is suppressed. If the animal carries only one copy of the mutant gene (it is heterozygous), it will look normal. If both parents carried the mutant gene, and passed it on, and the animal has two copies of that mutant gene, then the gene will be expressed and it will look like a mutant. An example of a recessive gene in humans is blue eyes. If your mother has blue eyes, but your father has brown eyes (and does not carry the blue-eye gene), then you will have brown eyes. Blue eyes is a recessive gene, so two copies have to be present for it to show up outwardly.
Co-Dominant mutation: The mutant gene is co-dominant (incomplete dominance is a more correct term for this, but co-dominant is what is used in the reptile community), and is only partially expressed when one copy is present--it is fully expressed when two copies are present. This is just like the recessive gene, except that the animal that is heterozygous LOOKS like a mutant, instead of looking normal. The animal that carries two copies of the gene (is homozygous) is often referred to as the 'super form'. So--if the animal carries one copy of the gene, it looks different from a normal, and if it carries two copies, it looks different from both a normal, and from an animal that carries one copy.
Here are some of the most common mutations found in reptiles:
Albino (AKA amelanistic): This is a mutation in which the black coloration is completely missing. Most albinos are also completely missing the brown coloration, so they will be yellow and white. Amelanistic animals have red or pink eyes.
Axanthic: This is a mutation in which the yellow coloration is missing. These animals will be black and white, or black, brown, and white.
Snow: This is a combination of both the amelanistic and axanthic mutations, which results in an all white animal with red eyes--the 'true albino' most of us think of.
Leucistic: This is a mutation that produces an all-white animal with blue eyes, or with black eyes.
Hypomelanistic: Hypomelanistic animals have reduced black coloration, so they appear faded or frosted, and their colors often seem brighter or richer.
Hypermelanistic: This mutation produces animals that have a lot more black coloration than normal. Some hypermelanistic animals are pure black.
Striped: This mutation causes an animal's normally blotched pattern to be replaced by a stripe, usually down the back.
Piebald: This mutation causes random patches on the animal to be pure white, while the pattern and color of the other areas is disrupted. Paint horses are piebald. Sometimes shortened simply to 'pied'.
Patternless: Fairly self-explanatory.
Jungle: The normal pattern is disrupted, replaced by one that is busy, and random.
There are a GREAT many other mutations as well. Some of the species that have been bred most heavily for color mutations include ball pythons, boa constrictors, corn snakes, leopard geckos, bearded dragons, king snakes, milk snakes, and crested geckos. The names of the various color mutations, and combinations, can range from very simple (albino), to something you think you should eat or wear (toffee, candy cane, lipstick), to downright weird (Spider (spider-webbed), Angel of Death (I kid you not, that's a real combo morph name).
Generally, the first person to 'prove out' a new mutation (by breeding it to prove that it is heritable, and how it is inherited), gets to name it. The first person to produce a new combination morph get to name the combo.