This is a link I give to a lot of people. Sometimes if you look around online you can find out whats Dom and rec. You might even be able to go to your vet and find out what your dom. and rec. traits are. If might cost a pretty penny but don't quote me on that lol.
They don't do gene-typing on rats. You would need to know the genetic history of your hypothetical pair. Who carries what, etc. Otherwise you could end up with a whole lot of top ear black berks. :lol:
Thats what I figured, about the black being dominant.
Well the female is just a black hooded and has nothing else that I was told of in her line.
The male is a blue rex...or so I was also told. He has very course, curly hair...so I just assumed that was right
Black (a) is not dominant, it's a base color. Either a color is agouti based or black based. Agouti (A) is dominant over black. Blue (g) is a dilute gene and is recessive, meaning you need two copies of the gene in order to produce blues (gg). Your other rat needs to carry blue in order to produce blues when bred to a blue. Rex (Re) is dominant, meaning you only need one copy of the gene to produce rexes. As far as markings go, I'd need to know what markings your blue has before telling you what markings to expect. If he's a self and he's bred to a hooded, you'll get 100% berkshires. If he's a berkshire and bred to a hooded, you'll get berks and hoods, if he's a hood and bred to a hood, you'll get all hoods. Irish to a hood will give berks, Irish and hoods.
Not to get down on anyone, but one really should learn this stuff BEFORE breeding because you are not doing anything to improve the rat fancy, just creating more plain rats that likely will have issues further down the line. We dont' need more rats in the fancy, we need better rats in the fancy.
I assume that if you want to breed that you got both the sire and dam from reputable sources, so it shouldn't be an issues to find out their genetics, right? Once you do that, then it will be easier to figure out what they may throw together.
Please though, since it seems that you don't know much about genetics, do some studying on rat breeding and ethics before you do it. Get a good mentor as well. Breeding isn't something that should be done lightly. You need to have a goal in mind and be working to improve the fancy, not just produce more rats.