Question: Breeding and Genetics

[Spartacus]

You guys probably get sick of genetics questions, but I only know the basics, so am hoping for some help.

I have two male leucistics, two golden females, one golden male, and one female wildtype.
I want to know if there is a good combination I can mix with each gold to figure out their
genotype. I want to figure out if they have Dd or DD in the mix. Can I match them with anyone to help get an idea?

My leucistics and wildtype always make half and half of each
Gold female #2 plus gold male equals golds
Gold female #1 plus leucistic equals wilds only

Is there any match up I can do to figure it out? Of their offspring in the future is also an option I'd like to consider, but don't know which way to go

Thanks!

 

[Kaysie]

So the only 2 really in question are Golden Female #2 and your golden male. Here's why:

We know leucies are always d/d, and goldens are D/x.

-Leucy (d/d) x Wildtype (D/d) will give you 50% D/d [dark], 50% d/d [light]
-Golden female #2 (D/x) x Gold male (D/x): Either one or neither is carrying recessive.
-Golden female #1 (D/D) x Leucy (d/d) will give you 100% D/d [dark]

Breed your golden male with your female wildtype (D/d). If your male is recessive (D/d), you'll get 25% light (leucistic or white albino, if the wildtype is recessive for albino). If your male is dominant (D/D), you'll get all dark (wildtype or golden albino, if the wildtype is recessive for albino) offspring

Breed Golden female #2 to a leucistic. If she is dominant (D/D), all your offspring will be dark (wildtype or golden albino, if the leucy is recessive for albino). If she is recessive (D/d), 50% of your offspring will be light (leucistic or white albino, if the leucy is recessive for albino).

 

[Spartacus]

Thank you! That is really helpful. I shall separate them according to your advice
Can I just ask what the x stands for in the D/x for goldens? Is that how you would write a genotype for a gold, either D/D or D/x?

Thanks so much

 

[Kaysie]

X is just an unknown. Sometimes people use D/- for an unknown.

In goldens, they're dominant for the the gene that causes color cells to migrate off the neural crest (D/x). You can't determine if they're D/D or D/d until you breed them with a leucistic or a carrier of leucism.

 

[Spartacus]

Thank you so much, you've been super helpful