Question about genetics

[VetTek]

I have what is probably an easy question about genetics. If you've got two parents who are dumbo-eared (and quite of few of the ancestors are dumbo-eared, with some being standard), wouldn't all babies from the litter then be dumbo-eared? I saw that it is a recessive genetic trait, so that means that both parents must carry both genes for dumbo ears in order to display that feature. That would then mean that all babies would have dumbo ears, regardless of the fact that previous ancestors may have had standard ears correct?

Thanks,
Deb

[mtmaughan]

I don't think that this is necessarily true. Genetics is more complicated than a simple 2-gene analysis of features. Take eye color. Two blue-eyed parents have been known to produce brown-eyed children even though blue is a recessive eye color. And we've all seen the occasional child that just looks nothing like his parents or siblings.

There is way more to heredity than the two allele combinations we learned about in high school biology. That's why babies are always a surprise!

[laydeerodentzz]

I don't think that, that is entirly true either, because of like pedigree dogs, they have to be bred right from the start to be classed as pedigree- as far as I know, I think in rats like that it depends more on inheritid (spelling?) genes, like they might not have the ears of a dumbo, but in fact the personality, you know what I mean??

[Padfoot]

What other posters have said is true, however, in the case of rat ears, dumbo and standard ears are dictated by a single simple gene (that acts according to mendelian genetics). In the case of human eyes, human eye color is given by several genes, not just one. So the actual color will not depend on a single gene, but a combination of genes. That's why blue-eyed parents can have a brown eyed baby and why there are different shades of green, blue and brown eyes. This is also true for human skin color and rat fur color.

I'll use a mouse color example, since I'm more familiar with mice colors genetics than rat color genetics. Mice have 5 main locus that dictate fur color. An agouti mouse (which is the wild color) is A* B* C* D* P* (where the letter is the dominant gene and the * could be either dominant or recessive). A black mouse would be aa B* C* D* P*. Here you see that just one recessive locus affect the fur color. However if the mouse's genetics are aa bb C* D* P*, then said mouse will be chocolate instead of black, but if it's A* bb C* D* P*, then the mouse will be cinnamon... get the point? Different genetics combination will make up the fur color.

In the case of rat ears, I looked up this site which has rat genetics: http://www.curiosityrats.com/ Rat ears are dictated by a single gene (du) A standard rat would be dominand (Du*) while a dumbo rat would be recessive (dudu). So, yes if both parents are dumbo, all babies have to be dumbo.

[Mousey]

well said!

[VetTek]

OK so two dumbo-eared parents would mean all dumbo-eared children, according to what you found out? Thanks for your help! I know that genetics isn't as simple as what was taught in high school, but there are some traits that are simple one-gene traits. I just wasn't sure if dumbo ears was one of them.

Deb

[Binky]

Well, sort of going off topic, but talking about the blue eyes, quite recently scrientists found evidence that every blue eyed person is related from the orginial one person who had mutated cells that changed the brown-eyed gene-ish-thing into being blue.
So yeah. =3

[Dragonrain]

Well every mutation has to start somewhere - usually it starts in just one individual and then spreads to a small population, then individuals from that population migrate and take the new mutation with them.

Off topic again I know, but genetics are really interesting