Friday, October 2, 2009

Rabbit Genetics: Basic Terminology

*NOTE* These terms are for ALL genetics. They are not particular to certain genetics, they apply to all.
Here are some of the basic genetic terminologies. I will mention these first that way you can understand what I am referring to at times.

Allele - See Locus

Carry - This means that a rabbit is hiding a gene for another color. It can hide a recessive gene. It cannot hide a gene that is from a different locus, it has to hide a gene from it’s own locus.

Chromosomes - The genetic make up if cells that reproduce themselves. This is where the DNA is. A domestic rabbit has 44 chromosomes (22 pairs), cotton tails have 42, and hares have 48.

Dominant - A dominant gene is stronger than a recessive gene. A dominant gene always shows up first. For example, if a chestnut agouti (castor, sandy, etc) carries self (non-agouti) the rabbit would appear as a chestnut agouti. The self gene will not show.

Genotype - The genetics of a rabbit. For example the genotype of a chestnut agouti is: A_B_C_D_E_

Heterozygous - This means that the rabbit is not pure for a certain gene. It carries a recessive gene. For example, “Aa” instead of “AA”.

Homozygous - This means that the rabbit is pure for a certain gene. It does not carry a recessive gene and it cannot produce certain colors. For example, “AA” instead of “Aa”.

Locus (plural - Loci) - This is the position of the gene on a chromosome. It is the series or set that certain genes are located in. Each locus has a specific letter name. For example, A Locus, B Locus, etc. Genes from one loci cannot be dominant or recessive to genes from another loci. There can only be two genes on one loci. One gene per locus is donated from one parent and the other gene is donated from the other parent to fill the 2 “slots” on the chromosome.

Modifier - This is a type of gene that is linked up with a certain gene and it modifies that gene. An example, is rufus modifiers. A rabbit with more rufus modifiers will have a deeper, darker, red coloring (e.g. Red). A rabbit with fewer rufus modifiers will have lighter, duller red color (e.g. Fawn). Rufus modifiers are shown as plus (+) and minus (-) signs. A rabbit with more plus signs will have darker color, a rabbit with more minus signs will have lighter color, and a rabbit with an equal amount will have medium color.

Phenotype - What the rabbit looks like. For example, I have a buck who looks (phenotype) like a broken chocolate but, his genotype is a broken chocolate steel.

Recessive - This is a gene that is weaker than a dominant gene. A recessive gene can hide behind a dominant gene but, it cannot hide a dominant gene.


rrj said...

Thanks you for your posting about basic terminology gene. Of course really useful for me.
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