stephanbakir
05-05-11, 11:23 PM
Found this on MonsterSnakeForums and figured some people here might find it useful. Originally posted by Rob w.
Lately I've been reading a lot of remarks on boards on snake genetics in which people talk about co-dominant genes while they are actually talking about incomplete or complete dominant genes.
Like most of you guys know, for each gene a snake receives a copy of each parent. Genes can be dominant, recessive, or co-dominant.
In recessive genes, the mutation will only appear if the animal receives 2 of the same copy's of the mutated gene. If it only carries one copy, the other normal copy will be dominant over that gene.
In dominant genes, the mutation will appear if just one copy of the mutated gene is transfered. This copy is dominant over the normal copy so it will show the mutation.
For compleet dominant genes, the homozygous form (which has 2 copy's) has the same looks (fenotype) as the heterozygous form. For example the spider ballpython gene is complete dominant. The homozygous form and heterozygous form look the same but different from the normal form.
The incompleet dominant genes are dominant so just one copy will show the mutation, but the homozygous form with 2 copy's will look different from the heterozygous form. This is the so called superform. For example: The platinum gene in retics is incomplete dominant. With just one copy of the mutated platinum gene, the animal will appear as a platinum, but the homozygous form shows ivory's and leucistics.
Well to get back to the reason why I posted this:
Co-dominant genes occurs when different mutations of the same gene come together. When putting one copy for each mutation together, both mutations will show at the same time.
I thought it would be usefull to post this, since 90% of the snakebreeders seems to use the term co-dominance incorrect.
Lately I've been reading a lot of remarks on boards on snake genetics in which people talk about co-dominant genes while they are actually talking about incomplete or complete dominant genes.
Like most of you guys know, for each gene a snake receives a copy of each parent. Genes can be dominant, recessive, or co-dominant.
In recessive genes, the mutation will only appear if the animal receives 2 of the same copy's of the mutated gene. If it only carries one copy, the other normal copy will be dominant over that gene.
In dominant genes, the mutation will appear if just one copy of the mutated gene is transfered. This copy is dominant over the normal copy so it will show the mutation.
For compleet dominant genes, the homozygous form (which has 2 copy's) has the same looks (fenotype) as the heterozygous form. For example the spider ballpython gene is complete dominant. The homozygous form and heterozygous form look the same but different from the normal form.
The incompleet dominant genes are dominant so just one copy will show the mutation, but the homozygous form with 2 copy's will look different from the heterozygous form. This is the so called superform. For example: The platinum gene in retics is incomplete dominant. With just one copy of the mutated platinum gene, the animal will appear as a platinum, but the homozygous form shows ivory's and leucistics.
Well to get back to the reason why I posted this:
Co-dominant genes occurs when different mutations of the same gene come together. When putting one copy for each mutation together, both mutations will show at the same time.
I thought it would be usefull to post this, since 90% of the snakebreeders seems to use the term co-dominance incorrect.