The article "Fish's DNA May Explain How Fins Turned to Feet" by Nicholas Wade is about how scientists have
decoded the genome of the coelacanth. The coelacanth was believed to be extinct
70 million years ago. However a specimen was discovered in Africa in 1938. There
has been a big discussion which fish, either the coelacanth or the lungfish, is
closer to the ancestral fish that first used to fish to walk on land. The
decoding of the genome of the coelacanth named the lungfish as the closer
relative.
However, the genome of the coelacanth, which
is about the same size as a human genome, can be decoded while the genome of
the lungfish cannot. Researchers have been looking through the coelacanth’s
genome for genes that might have helped the ancestral fish to be able to walk
on land. So far they have found one gene that is related to those who build a
placenta. Since coelacanths have no placenta, they think that the gene could
have been developed by land animals into a way to construct a placenta. Another
preadaption they have found is a snippet of DNA “that enhances the activity of
the genes that drive the formations of limbs in the embryo”. They tested it out
on a mouse and the mouse actually ended up forming a limb.
"The Amemiya team does not possess a full coelacanth — these are endangered species — and decoded the genome from tissues obtained from Rosemary Dorrington of Rhodes University in South Africa. Dr. Dorrington supplied DNA kits to the Comoro Islands fishermen who occasionally snag coelacanths by accident." When one is found, its blood and tissues are preserved and then given to Dr. Dorringtion to keep frozen.
The scientists are trying to discover what allowed the ancestral fish to be able to go on land. By studying the coelacanth's genome. By studying them, they might be able to find how it was possible. They are trying their best to find out how. This article has been really interesting to read and I am looking forward to see further research.
No comments:
Post a Comment