Genetic Anomalies in Rats (II)

Before you proceed any further please take your time and go through my previous post, actually the first part of these series about "Genetic Anomalies in Rats (Part I)". Thanks

Hairless Dumbo and Rex Rats

Rats are given the credit for being the most useful animal in the laboratory -- most of the medical and scientific breakthroughs that mankind have, relative to genetics, might have been impossible without the help of the laboratory rats. Many of these rats have been breed for the sole purpose of being used in laboratory testing; a lot of breeds actually sprout out from these experiments. Two of the most controversial laboratory-produced rats are the Hairless Dumbo and the Rex Rats. The Dumbo, because famous by virtue of them having no hair and the Rex Rats gained their popularity because of their curly hair.

Rex Rats

These rats have very dominant genes that we can almost be certain that every time a Rex is bred with a regular rat, the offspring will definitely become a Rex. For this reason, scientists have actually deduced that Rex Rats no longer need to interbreed (or breed with other Rex Rats) just to preserve their kind. Whenever they breed with other rats, they would generally produce their kind. This characteristic causes both fear and awe among scientist. Awe because not all rats have such strong genetic characteristic; and yet, this is fearsome because it can also cause the extinction of the other rat specie.

Nevertheless, scientists have already tried to breed Rex Rats with weaker genetic traits. They did this in order to see how the traits of a Rex rat (most especially the curly hair) would mix well with the traits of other rats. Without weakening the genetic traits of the Rex, it will be impossible to see the traits of the other rat interplay.

Double Rexes

There are cases when a "genetically weak" Rex is born with curly whiskers and covering, only to lose them after a few weeks. The rat will be "naked" within those days while it is waiting for its hair to grow back. Most of the time, the new covering would be completely different from the previous one, either it will have more patches (of black, grey and brown) or it will lose most of its patches and appear almost completely white. These rats are called the Double Rexes; the name evolved from the fact that the most possible reason why these anomalies happen is because even after the gene of the Rex Rat is weakened, it still resulted to over-rexing.

Over-rexing which occurred for many generations can lead to hairless Rexes or Rex Dumbo. Majority of the hairless Rats that we see in movies and even in pet shops are actually Rex Dumbo. Nonetheless, because the disappearance of the hair is only caused by a genetic anomaly, this Dumbo can still give birth to hairy and curly Rexes in the future.

Hairless Dumbo

Rats without furs do not exist in the wild. Of course, animals have furs because they need to be protected from the temperature outside and by normal evolution; it is but natural for rats and other animals to grow furs. However, in the laboratory setup, rats and other laboratory animals do not develop their traits based on environmental and survival needs. Because of the genetic anomalies caused by scientists, many animals, especially the rats, became extremely unique that it would be impossible for them to survive in the wild. One example of which is the Hairless Dumbo.

These rats are very fragile and they are very susceptible to many diseases because of their very weak immune system. They are used to test chemicals, radiations and gases which many other animals may be strong enough to resist. Bottom line is, because they are weak (but still exhibit the same DNA and other traits as other strong rats have); they are very effective as test animals for applications which use poisons and other harmful toxins in very small dosages.