Ce sujet est fermé
I'm going to take a stab at this.
Ok first lets set down a few facts. First we know that 1% of the Asari population show some degree of AY traits. Second we know that the full expression of the AY trait is said to show up in the children of pureblood Asaris.
Hypothesis: AY genetics are not classic dominant resessive genetics but more like the genetics that govern hair color and eye color.
Therefore let us go over the latest theories of how you end up with blue or brown eyes in humans. Sorry for the long read below
From: http://www.thetech.o...s/ask.php?id=29
What we are taught in high school biology is generally true, brown eye
genes are dominant over green eye genes which are both dominant over
blue eye genes. However, because many genes are required to make each
of the yellow and black pigments, there is a way called genetic
compensation to get brown or green eyes from blue-eyed parents.
Genetic Complementation
The best way to illustrate how this might happen is with an example.
Let's say there is a genetic pathway made up of four genes (cleverly
named A, B, C, and D) that are needed to make brown eyes. A mutation in
both copies of any one of these genes results in blue eyes (these
mutations are denoted with lower case letters, a, b, c, and d).
Now let's say that dad has blue eyes because of a mutation in both his
copies of gene A and mom because of a mutation in both her copies of
gene D. As I am sure you know, we have two copies of each gene, one
from our mom and one from our dad. If either parent gives you a brown
version of a gene, it will be dominant over the blue copy.
Let's suppose that mom gives you a brown copy of gene A and dad gives
you a brown copy of gene D. What color eyes would you have? Brown.
(The same argument works for green eyes as well.)
Another common genetic process that could be responsible for brown eyes
from blue-eyed parents is called recombination. When eggs and sperm
are made, only one of a pair of chromosomes gets put into an egg or
sperm. Before this happens, there is a bunch of DNA swapping that goes
on between the pair of chromosomes. Sometimes when the DNA is swapped
or recombined, DNA mutations get fixed.
Recombination
Again, an example can show how this might work. Imagine dad has blue
eyes because of a mutation at the front end of one copy of his eye color
gene and a different mutation at the back end of the other copy of the
gene. Each gene has a single mutation but at different places in the
gene (see Figure 2).
Now imagine that when his sperm is being made, the middle part of the
eye color gene is switched between the two genes resulting in one brown
eye gene and one blue eye gene with two mutations. Now dad can produce a
brown-eyed child. (Again, the same argument works for a green eye gene
as well.)
Back to the AY explanation:
Ok when you're talking about genetics remember that what genes are actually are blueprints for how to make things like protiens and such. So lets say you have a location in a chromosone and if you have gene A then the protien that is produced contributes to the person being an AY, if you have gene a then the protien is just slightly different enough that you meld in what is considered a normal manner.
In this case we are specifically saying that the protien produced that causes the AY expression is both a mutation from the normal gene and that is is dominant over the normal gene.
So lets start with our hypothetical Asari mother. She carries some of the genetics for the AY.
A a A a a A
Now when she decides to have a child she actually provides both copies of the chromosone and then randomized the second copy with information from the "father" If the father is not asari then there is no chance they will carry any AY genetics.
So we have: A a A a a A & a a a a a A (the randomization overwrote some of the A genes witih good copies of the a gene) and the child is - A a A a a A the same as the mother since the trait is dominant. Not great but not any worse off either.
Now the same asari decides to have a child with another asari. Unfortunately they both belong to the 1% of asari that carry some of the AY genetics.
The mother is again - A a A a a A and the asari who is the father is - a A a A A A
Again both copies of the gene come from the mother and are randomized with the father's genetics only this time
A a A a a A + A A A A A a = A A A A A A
This is the only way I can see it working, Nick if you can figure out a way for it to work and be recessive and still manage to fully express itself I'd like to see it. I do think that the genetics of the AY would have to involve multiple genes in different areas of the chromosone though.
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