The Mammoth Walks Again
[intro]We all know of mammoths. We have all seen pictures (or shall we call them paintings) of Wooly Mammoths being hunted by our distant caveman ancestors. And we have all thought – this looks exactly like an elephant, but for the fur!
The last mammoth died thousands of years ago. Now perhaps it is time they walked the earth again.[/intro]
Yes, scientists have figured out a way to clone or to put it more accurately resurrect a mammoth like creature.
There is a reason why the mammoth looked like our modern elephants. Both the species are descended from a common ancestor. However while the modern elephants have evolved to survive in a tropical climate, the mammoths were built for the ice age.
So what made the mammoths different – shaggy wooly coats, layers and layers of fatty tissue and of course smaller ears (ears are how an elephant loses heat). But that’s just scratching the surface. Now, for the first time, researchers have been able to list down all genetic differences between the two species.
It is now possible now to trace the genetic steps that helped the wooly mammoth evolve from the ancestor of the Asian elephant. This can also help us modify elephants in such a way that they can thrive in the cold wastes of Siberia.
Well, scientists are already working towards this goal in a research lab in Boston Massachusetts.
Actually work on the Wooly Mammoth Genome has been going on for quite some time. The first complete se was published way back in 2008. However, there were way too many errors in it and was insufficient to tell us how elephants and mammoths differ genetically.
Next, scientists started working on the individual genes of mammoths to understand how they helped create those characteristics that helped these animals survive in the ice age cold.
The Artic Pachyderm
In the forefront of this field have been evolutionary geneticists from the University of Chicago led by Vincent Lynch. They managed to completely sequence the genomes of two wooly mammoths and three Asian elephants. (A miracle considering that the mammoths were 20,000 and 60,000 years dead!) And what did they find – close to 1.4 million DNA letters which differ in the mammoths from the elephants. This resulted in a significant change in 1.600 protein coding genes.
The next step was to compare the proteins with what they did in other organisms. This helped the researchers to identify and isolate those particular genes that are used for storing and metabolizing fat, developing skin and hair and other characteristics that can be crucial to surviving ice age cold.
Some of the genes, for example, dealt with the resetting the circadian clock – to help cope with long dark winters and 24×7 daylight in summers. Other arctic animals like the reindeers already have the same genetic make up.
Mammoths also have special genes that help produce fat cells and are used in insulin signaling. Among humans, these same genes are linked to diabetes.
Some of these genes seem to be useful in helping the mammoth to sense heat, a critical ability in the arctic cold.
Resurrecting The Mammoth
Lynch and his team managed to recreate the heat sensing genes as it would have existed in the mammoths. These genes help produce a protein called TRPV3 and helps in the growth of hair and skin. When inserted into the human genome it was seen that the gene makes the organism less responsive to heat or rather more resistant to cold compared to the corresponding genes as present in modern day elephants.
This fits perfectly with a previous research where it was found that this version of the TRPV3 protein gave mice wavier and longer hair as well as made them more cold-friendly.
So what is team planning next? According to Lynch, the aim is to insert these genes into elephant cells and then examine the changes.
A Mammoth Step Ahead
In the Harvard Medical School, geneticist George Church is working on the same challenge with the help of a revolutionary technology called CRISPR/Cas9. This allows the scientists to easily edit genes.
The result – he and his team have managed to create elephant cells with 14 mammoth genes that specific to helping cold tolerance.
According to Church, this is just preparation for the time when they will be able to edit the complete mammoth genome and even resurrect the wooly giant. The other (and much easier) option would be to modify the Asian elephant with mammoth genes so that it can thrive in Siberia. In fact, Pleistocene Park, a 16 sq km reserve in northern Siberia is already being proposed as a home for arctic elephants.
But just because scientists could be able to do it does not necessarily mean that they are going to do it. Beth Shapiro, another evolutionary geneticist has written a book called “How to Clone a Mammoth” in which she lists down the many blocks to the actual genetic resurrection of the mammoth. This includes ethical considerations to the fact that science of Elephant reproductive biology is still at its nascent stage,