Working Out Genetics (With Pretty Tables!)

[Nell]

So now that we have another colour of suggie in the UK there seems to be a little bit of confusion as to genetics, so here is a simplified way of determining genetics where a recessive gene is concerned. Ignore things in **'s unless you want to know technical terms (they may confuse!)

First a simple definition: a recessive gene is one which is only obvious (*displays the phenotype of that gene*) where it is present twice (*it is homozygous and its allele is identical*) -so either both parents had that gene or there has been a mutation in the animal's DNA. This is important as it means that individual's may be 'carriers': they have that gene but do not display it due to another 'dominant' gene.

So, say the trait of our gene is Leucism (i.e. the gene which creates leucistic sugar gliders) we shall call that gene 0 (as there is less colour present) the dominant gene whose trait is normal grey gliders name is 1.

In order to determine the outcome of a pairing of gliders you should put the names of the genes into a table as show below

1 is dominant therefore all offspring from this pairing will appear grey, but carry the leucistic gene.

In these second pairings we have sugar gliders with genes 10 as shown above -this means they are a carrier (*AKA Heterozygous or het*) for leucism.

In the first pairing you can see there will be one glider who is leucistic (circled in red) as they have two 0 genes. Therefore  any grey gliders from this pairing will have a 66% chance of being a carrier, as you don't include the glider which IS leucistic in your percentage calculations, as you can tell their genes by looking at them. The glider therefore only has 3 genetic options, 2 of which are 10 (carriers) so a 66% chance, and 1 option of being a standard grey (33%).

The second grid shows the pairing of a normal grey and a het leu, the same calculation is used to determine the chance of leucism in the offspring (i.e. there are 2 options for each genetic combination 2 divided by the total number of options, 4=0.5 which equates to 50%)

Hope this is useful guys, it took me bloody ages to find a website I liked to draw the graphs with!!  

Het Leu crossed with a Leucistic glider added by popular demand xD

Using the calculation above there are equal chances of leucistic joeys and het leucistic joeys.

[Amalthea]

I was just coming to the computer to do exactly this *lol* You forgot to do one for het leu x leu

[Nell]

I was just coming to the computer to do exactly this *lol* You forgot to do one for het leu x leu

Great minds think alike eh?! I'll do one now and add it to the post

[wjohnw]

(basically what I said in the other topic) lol

[Amalthea]

Definitely do!! These are how Dad taught me to understand genetics when I was a kid learning in school *lol*

[Nell]

Added them  Hehe sorry John I didn't see that, too busy making my pretty graphs!  - I did say I'd make a separate topic I guess this will make it easier for people looking for genetic info, rather than having to trawl through posts full of us chatting ^^

[munshkin]

Thanks Nell,
I like things like this, easier for my "dizzylexic" brain to understand. i am lucky to have a son in law who studied genetics at uni so i can pick his brains if/when the time arrives to use it before i am far too old and dementia has set in (hint hint Marie!!)

[Marie]

Ahh, the 'punnet tables'.  TBH I was praying you wouldn't do them as they are what confused me in the first place, but it is a lot clearer now!

We didn't study genetics at school, I think I went to a weird school as we didn't even study Shakespear in English Lit!

[Marie]

see ... I can't even spell his name!  *Shakespeare*

[Amalthea]

How strange! *lol*

[wjohnw]

Yes, the 'dreaded punnet square', the one in the other topic is the same ( but without the lines for the square lol) but it's actually one of the easiest visual descriptions to use, there are a number of more complex methods at illustrating this sort of thing.