The Corn Calculator

The Corn Calculator - Online corn snake genetics

Glossary

TermDefinition
Allele - One of a series of alternate forms of a given gene.
 
Alleles have the same locus. Each set of alleles contains a wild-type allele and one or more mutant alleles.
  
Albino - 1. Partially or totally lacking in some pigment. Although albino plants lack chlorophyll, the term is usually applied to living things that partially or fully lack black pigment. Although similar to "amelanistic", the word is broader in meaning. 2. The unique name given to a single mutant gene that partially or fully prevents black pigment from being produced. (Slang: amel)
  
Amelanistic - 1. Without black pigment. 2. The unique name given to a single mutant gene that prevents black pigment from forming. (Slang: amel)
  
Anerythristic - 1. Without red pigment. 2. The unique name given to a single mutant gene that prevents red pigment from forming. (Slang: anery)
  
Chromosome - One of the thread-like structures found in the cell nucleus. Chromosomes are easiest to see when they are dividing. An X-shaped chromosome is a single chromosome that is dividing, not a pair of chromosomes. Chromosomes are made of DNA, RNA, and protein. Chromosomes contain genetic information, the genes, arranged in a linear sequence in the DNA.
  
Codominant - 1. A mutant gene that is codominant to the wild-type allele. See dominance relations. 2. Incorrectly used in many herper web pages for an animal that is heterozygous for a codominant mutant gene.
  
DNA - Deoxyribonucleic acid, the molecular basis of heredity. Each chromosome contains one molecule of DNA. The molecule looks like a ladder that has been twisted lengthwise. The ladder's rungs are the base pairs while the ladder's uprights form the double helix. The sequence of base pairs is the genetic code.
  
Dominance relations - The answers to three questions determine whether a mutant gene is dominant, codominant, or recessive to the wild-type gene. (See also Dominant, Codominant, and Recessive Mutant Genes)
 
1. Does a creature with two mutant genes look like an animal with two normal (wild-type) genes?
In all cases, the answer should be no.
 
2. Does a creature with one mutant gene paired with a wild-type gene look like an animal with two normal (wild-type) genes?
If yes, then the mutant gene is recessive to the wild-type gene. Stop here.
If no, then go to question 3.
 
3. Does a creature with one mutant gene paired with a wild-type gene look like an animal with two mutant genes?
If yes, then the mutant gene is dominant to the wild-type gene.
If no, then the mutant gene is codominant to the wild-type gene.
  
Dominant - 1. A mutant gene that is dominant to the wild-type allele. See dominance relations. 2. Incorrectly used in many herper web pages for an animal that is homozygous for a codominant mutant gene.
  
F1 generation - 1. In genetics, the first filial generation. The offspring of the P1 generation. 2. Sometimes, the first generation bred in captivity. When used this way, both parents are usually wild type.
  
F2 generation - 1. In genetics, the second filial generation. The offspring produced by crossing or self-fertilizing F1 individuals. 2. Sometimes, the second generation bred in captivity.
  
Gene - A functional hereditary unit. A gene is a specific sequence of base pairs in a chromosome's DNA molecule. A gene may contain from one to over a thousand base pairs.
 
A gene occupies a specific position (locus) within the genome. It has one or more specific effects upon the appearance (phenotype) of the organism.
  
Gene pair - A gene in a given location in one homologous chromosome and the gene in the same location in the other homologous chromosome.
  
Genome - All of the genes in a single sperm or egg. Each sperm or egg contains one from each pair of an adult's homologous chromosomes, so each sperm or egg contains one gene from each parental gene pair.
  
Genotype - The identity of the genes that are present in the cells. See phenotype.
  
Heterozgyous - The two genes in a gene pair are not the same; they are different. (Slang: het.) See homozygous.
 
A heterozygous gene pair can be a wild-type gene and a dominant mutant gene, a wild-type gene and a codominant mutant gene, a wild-type gene and a recessive mutant gene, or two different mutant genes.
  
Homologous chromosomes - When cells divide to produce sperm or eggs, chromosomes form up into pairs. Each chromosome is more similar to the other member of the pair than to any other chromosome (sex chromosomes, if present, excepted). The two chromosomes in each pair are homologous chromosomes.
 
The corn snake has a total of 36 chromosomes in 18 homologous pairs.
  
Homozygous - The two genes in a gene pair are the same. See heterozygous.
 
A homozygous gene pair can be two wild-type genes or two identical mutant genes.
  
Hypomelanistic - Reduced black pigment. (Slang: hypo)
  
Locus
(plural = loci)
- The position that a gene occupies in a chromosome. That position does not change for most genes most of the time.
  
Multiple alleles - Three or more alleles.
  
Mutant - A difference from wild type that can be passed down through the generations. The word can refer to either the genotype or phenotype.
  
Normal - See wild type.
  
P1 generation - The parental generation that starts a genetic experiment. The male and female are different in one or more gene pairs. See F1 generation, F2 generation.
  
Phenotype - An organism's appearance and any other physical manifestations produced by the interaction of the genes' effects with the environment. Synonyms: trait, character, characteristic. See genotype.
  
Recessive - A mutant gene that is recessive to the wild-type allele. See dominance relations.
  
Trait - See phenotype.
  
Wild type - 1. The most common phenotype in the wild population. 2. The most common allele at a given locus in the genome of the wild population. Synonym: normal. Antonym: mutant.
 
The wild-type allele is not a dominant, codominant or recessive allele. It is the standard. A mutant allele is compared to the standard. This comparison determines whether the mutant is dominant, codominant or recessive to the wild-type allele.
  

The Corn Calculator uses its own symbols to denote the corn snake genes. This table shows the more widely accepted symbols for each series of alleles.

GeneSymbol
Amelanistica
Ultraau
Wild typea+
  
Anerythristican
Wild typean+
  
Caramelca
Wild typeca+
  
Charcoalch
Wild typech+
  
Cinderci
Wild typeci+
  
Diffusedd
Wild typed+
  
Dilutedt
Wild typedt+
  
Hypomelanistic  h
Wild typeh+
  
Kastaniek
Wild typek+
  
Lavav
Wild typev+
  
Lavenderl
Wild typel+
  
Motleym
Stripems
Wild typem+
  
Sunkisseds
Wild types+
  
TerrazzoNot yet assigned
Wild type+