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Platypus Genome Revealed

I made a blog like 3 years ago and ended up throwing the site out due to lack of time and interest. But now, amidst the revision time for upcoming exams, I find that interest again as I wanted to share some of my ideas about things in life. Anyhow, let's start off with something very interesting.

The advent of genome sequencing revealed a lot of information on the organism in question. Genome sequencing is used as a tool to assess the global nucleotide sequence of an organism and with such knowledge, comparison of different sequences can reveal phylogeny or relatedness of one organism to another. And extending it further, this would also make us aware how did a certain organism evolve and what makes it special.

The first bacterial genome to be sequenced was the Haemophilus influenzae (Fleischmann, 1995). Using a technique called random shotgun sequencing. Basically the technique requires fragmentation of genomic DNA of an organism, then clone it in a bacteria and sequence it using Dye terminator technique. Until now this technique is widely used. In fact, that is how the first human genome sequence was completed in 2003. And now, the genome sequencing had been extended to a lot of organisms.
"It has a very weird appearance because it's a mishmash of the bill of a duck, the eyes of a mole, the eggs of a lizard and the tail of a beaver." - Dr. Ponting, Oxford University (Picture from: PERLGURL.ORG)

The most recent addition to the growing number of completed genome sequence is the platypus. And indeed, this creature's genetic make-up is worth studying. The organism is like a hodgepodge of many other organisms. Dr. Ponting of Oxford University told BBC that: "It has a very weird appearance because it's a mishmash of the bill of a duck, the eyes of a mole, the eggs of a lizard and the tail of a beaver." And indeed, the genome sequence revealed that it shares the features of a bird, reptile and mammal.

The platypus has a distinct characteristic of possessing a gene for producing milk proteins called caseins. Although, they don't have nipples, their youngs can feed on through glandular patch on its skins. This finding may provide an insight as to how the ancient mammals evolved to possess the mechanism to feed their youngs as well as how mammals evolved to produce milk, which is distinctive to reptiles.
Another interesting insight is the platypus' gene for egg development. The platypus possessed genes shared with chicken, amphibian and fish. The presence of vitellogin-making gene can be linked as to how mammals slowly evolve into viviparous.

There is some more interesting thing about the platypus, for instance, their venome and their claw features, which is somehow related to reptiles. Check out this LINK to find out more about the genome of platypus - but I don't know if you can access it for free.

Personally, I find this kind of research interesting but I am not really a big believer of phylogeny. Primarily, because I find that branch of science a bit useless especially when you put it in bacterial terms. Why? One is because, nobody knows how many organisms we have in this world and an attempt to characterise each species is tedious and no way can be completed. It is like trying to finish a picture puzzle without the knowledge of what is the outcome of the picture. Another thing is, organisms mutate and evolve. This phenomenon is much more prominent in small creatures such as bacteria. After characterising a bacteria, you may even not know if it is already extinct or acquired different traits renderring it to become a different species.

But whatever is the case, probably the understanding of how humans evolved or came to be is just satisfying. Scientists are just DYING to know what makes us different from other animals. Platypus just happened to become THE missing link of mammals and reptiles. One way to further assess and ascertain the standing of mammals in the phylogenic tree is to try sequence the whole genome of echidnas. Echidnas are organisms under monotreme and just like platypus, they lay eggs but nurse them like mammals. So, expect something good in the future. I bet some groups are already taking charge of this echidna genome sequencing.

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