- 0
- #1
Need a refresher on the basic of genetics? Or just a crash course? This is the thread for you!
Basics
Here at Hopscotch we're concerned with how genes impact the appearance of our buns, but genes do a whole lot more than that! Genes provide instructions for how to produce a protein. Genes control almost every facet of a creature - how they function, how they look and even influence how they act.
What genes a rabbit has make up the genotype, which is generally written in shorthand. (Eg. bb Dd atat) Rabbits also have a phenotype, which is what they look like. (Eg. Broken Lilac) It is important to remember that a phenotype only describes what a rabbit looks like, it can't describe carried recessive traits. The phenotype is made up of the expressed alleles.
In summary: a phenotype is what a rabbit looks like, a genotype is a rabbits's genetic make up.
Genes can have variants - these are known as alleles. Rabbits have two alleles for each gene, one from each parent. There can be many different alleles for a single gene. All of these gene variants are called a series. Each gene, made up of two alleles, is located on DNA. The specific place these genes exist is called the locus.
In summary: two alleles form a gene at a locus on DNA.
Dominance
All rabbits have two alleles for every gene, but usually only one of these alleles is expressed. The most dominant allele is the one that is expressed. Recessive alleles are masked by dominant alleles. A series may be multiple alleles which all have a different level of dominance. In genetic short hand, the dominant allele is written with a capital letter (eg. B, for black) while the recessive trait is written with a lower case letter (eg. b, for chocolate.) Some alleles are also co-dominant, meaning both alleles present are expressed. Even with co-dominant genes usually the more dominant allele is expressed more strongly.
In summary: dominant alleles are expressed over recessive alleles, unless the gene is co-dominant, then both alleles are expressed.
Inheritance
When rabbits breed each parent contributes one allele from each locus to the new kit. Which allele is contributed is completely random. Each allele has a 50% chance of being given to the kit.
Predicting Breedings
If you're trying to determine what colours and patterns will turn up in a litter, or how you ended up with the colours and patterns you got in a litter, a Punnet square is an easy way to work it out.
Making and using a Punnet square is easy. To work out a 1 gene Punnet square make a 2x2 grid. Put both alleles from one parent along the X axis, and both alleles from the other parent along the Y axis. Then working column by column and then row by row, fill in the cells! 1 allele comes from parent 1's column, 1 allele comes from parent 2's row. It doesn't matter if you fill in rows or columns first - this has no impact on the results! The completed cells will allow you to see what the possible genotypes are. You can also calculate how likely you are to receive each allele combination.