To make a genetic calculation between two animals, you need to know which genes both of the parents have. You have to make the genetic code equal to be able to cross them. It looks a bit like algebra at chool (2a + 2b = 4ab), but it works a bit differently. After calculating the genetic codes you can trace it back to a color. It sounds more difficult than it really is, you just have to know how it works.
To get hold of the genetic code of each parent, you have to know their color. In the color guide, you can look up the color and find the genetic code. In the list of genes of African Pygmy Hedgehogs and the page about inheritanceforms you can learn how genes inherit. Recessive genes are written in small letters, dominant genes are written in capital letters.
Father of the litter is a Brown Reversed Pinto, his genetic code is bb PI^rv. Mother of the litter is an Algerian grey, her genetic code is dd U*. Because Algerian is dominant and we don’t know whether she is heterozygous or homozygous, we may place an asterisk for the second allele which is unknown.
Now we have the genetic codes of the parents, we want to make the genetic codes equal.
Father of the litter is bb Pi^rv, mother of the litter is dd U*. When making a genetic calculation you always take the full list of the color genes plus all genes for patterns, so that you’ll always have equal codes to cross. Dominant genes that are not available in the other animal are written in small letters, whilst active dominant genes are written in capital letters. These work they other way around, compared with recessive genes.
Father becomes A* bb C* D* P* uu Pi^rv
Mother becomes A* B* C* dd P* U* pipi
Now that we have two equal genetic codes, we can cross them. we’ll do this by taking each gene seperatly and cross them with the same gene on the other animal.
A* x A*
bb x B*
C* x C*
D* x dd
and so on for each gene in the code. It’s easiest to do this in Excel like the sample below. The pink boxes is where you put the genes from mother’s side and the blue boxes is where you put the genes from the father’s side.
After inserting these tables and dividing the genes into them, we can calculate the outcome for each gene. Simply by combining the allele from above with the one on the side in each green box.
Now that the calculation itself is done, combine all genes back into genetic codes.
Start by doing the color genes only, the chances on patterns are easier to do afterwards.
AA Bb CC Dd PP
AA Bb CC Dd P*
AA Bb CC Dd **
AA Bb CC *d PP
AA Bb CC *d P*
AA Bb CC *d **
AA Bb C* Dd PP
AA Bb C* Dd P*
AA Bb C* Dd **
And so on until you have made every possible combination. Then look at the genes for patterns like in this case Pinto (PI*) and Algerian (U*). In this case we can see Uu and *u in case of Algerian, this means there is 50% chance on Algerian unless the mother is homozygous on Algerian (UU) then it will be 100% Uu and therefore all hoglets will become Algerian. In case of the Reversed Pinto, this is a bit more complicated. This is a codominant gene, which means the Reversed Pinto gene (rv) is recessive and it need the Pinto gene (PI) to become visible, otherwise it’ll be carried. In this gene we see 50% PIpi, which is Pinto and 50% pirv, which means non-Pinto but carrying Reversed Pinto.
After having checked all possibilities on the outcome, go back to the colorguide to see which colors match with each code. The more you’ll practise these kind of calculations, the easier it will get.
Help! I can’t figure this out!
Do you need help doing a genetic calculation? Feel free to contact us! A link to the pedigrees of both parents could help to get a more detailed calculation, making the prediction towards the outcome more accurate. But when you don’t have any info on their background, we can make a shallow calculation like we did above in the explanation. If you like to learn, but you don’t know where to start, we can easily calculate their genetic code for you, so you can keep practising.