Achondroplasia is a genetic disorder that is associated with the fibroblast growth factor receptor 3, or FGFR3.
This gene causes problems with the bong growth where in the bones of the body, vertebrae and ribs end up being non elongated and narrowed. When it comes to humans, achondroplasia is confirmed through X-rays and ultrasound tests.In one current research for achondroplasia, mice were used. Here the scientists used gene targeting to bring about a mutation in the FGFR3 gene. This resulted in dominant dwarf mice being produced. These mice were small in size, suffered from hypoplasia of the mid face, had protruding incisors, the craniofacial region was shortened, the cranium was distorted, and they suffered from narrow and distorted growth in the long bones, ribs and vertebrae. The mice produced 242,257 offsprings, and 7 offsprings were born with achondroplasia.
From this research on mice, the scientists arrived at the rate of mutation. They found that the rate of mutation of normal allele to achondroplasia allele was approximately around 1.4 times.
Similarly, another research on achondroplasia was undertaken. Here a normal bull was mated with cows. The result was birth of 28 calves that were normal and 25 calves that had some malformation. These calves with malformation were born alive, but some showed more malformation than others. Out of these, the scientists reared one bull calf and four heifer calves. They found that these 5 calves grew at a slower rate compared to normal calves. The bull was a dwarf and could not mate. On the other hand, the heifers were not as abnormal in size and they showed signs of fertility. However, the fertility as well as the milk production was not at par with the normal heifers.
Through the experiment this experiment, scientists figured out that the achondroplasia gene in this case was a simple recessive gene, and the dominance of the gene was not at all associated with the sex.
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