Here are some of AR Kiah's babies, all dumbos. Kiah lived with me until she recently accompanied some babies to thier new home to make their transition easier and stayed on there as a pet. These babies have moved into homes all over the midwest and are delighting their owners to this day!
Here's Bryce (cinnamon berkshire rex dumbo) with his buddy, BR Lumiere, a pearl rat. They were introduced to each other when they were young, so they got along very well. It is possible to introduce older male rats to one another, but it requires time, patience, and vanilla extract.
Here are AR Kiah (yes, again) and her daughter, AR Allegra. Kiah is an agouti rat. Agouti is the natural color of wild rats, but domestic agouti rats are usually redder than wild rats, which have more of a greyish-brown color. This coloration is produced by a gene called A. If a rat is AA, it cannot produce black or any of the other non-agouti colors. If it is Aa, like Kiah, it can produce black or another non-agouti color if it is bred to another Aa rat, or to an aa rat. All Aa rats are agouti or one of the other ticked colors. This means that agouti is dominant to nonagouti. aa rats do not display the agouti color or any ticking (striping of individual hairs) in their fur. aa rats are black or one of the other non-agouti colors, such as beige, mink, blue, etc.
AR Paco was a siamese tailless rat. He retired to live with Becky Jones in Cincinnati, Ohio. Tailless rats are difficult to breed, because the tailless trait is an example of either incomplete penetrance or multifactorial inheritance. This means that even if the rat is genetically tailless, it may still have a tail. Confusing, eh? I thought so too. I no longer breed this variety.
There are a number of possible expressions of these genes. Usually it results, as in Paco's case, in a more rounded rump and a bouncier gait along with the complete absence of a tail or tail stub. One of Paco's brothers was an example of a less desirable variation. He was born with a tail, but the tail had no muscles or bones and simply dragged behind him. He was a special pet of Becky's and enjoyed a good life despite his unusual appearance. Tailless rats should be bred only by experienced and careful breeders; inbreeding too much can result in horrible deformities and suffering in the babies. However, a well-bred tailless can be a delightful bouncy rat; some feel they have more outgoing temperaments.
This is Birch Hill's Sterling, from Pat Whipple's rattery. He is a platinum dumbo boy. He went to live with Alicia Gangi. A platinum rat is, genetically aarrgg (looks funny, huh?) This means that at the A locus, the platinum rat is non-agouti, which is recessive. The R locus controls red-eye dilution, which lightens the fur color. On a black rat, it causes beige and fawn. But platinum is a dilution not of black, but of blue. You guessed it, blue is gg (G is the grey locus, which in the recessive state causes blue dilution). For standards on the above-mentioned colors, check out //www.rmca.org/ , the homepage of the Rat and Mouse Club of America. Look for the "standards" section for more info.