Elephant Shark Genome Decoded: New Insights Gained Into Bone Formation and Immunity

Shruti Suresh

Period 2 Mathieu
Biology Honors
11 January 2014

Published: 8 January 2014
Author: Caroline Arbanas
Source: http://www.sciencedaily.com/releases/2014/01/140108133147.htm


Summary:
        Researchers from all over the world sequenced the genome of a curious animal, the elephant shark, on the 8th of January. The elephant shark is one of the world's oldest-living jawed vertebrates. A peculiar trait about them is that their skeleton is in fact made of cartilage rather than bone making them a bizarre organism on the evolutionary tree. By comparing the genome of the elephant shark with the genome of humans and other vertebrate, the researchers have identified why the elephant shark's skeleton is cartilaginous. By analyzing the different genomes, the researchers discovered a group of genes that were present in all bony vertebrates except for the elephant shark. When the scientists experimented and removed these certain genes from another organism-the zebrafish-it resulted in a significant reduction in bone formation. Coincidentally, the scientists also discovered that the elephant shark lacked special types of immune cells that were necessary for mounting a defense against viral and bacterial infections. Despite this, sharks exhibit strong immune responses and live long. The researchers also decided that the elephant shark genome is the slowest-evolving compared to other vertebrates.

Connection:
        This article is directly relevant to our curriculum because by analyzing and comparing genomes of different  organisms, we can discover newer, and more efficient ways to help and shape our own functions. For example, by knowing that sharks have strong immune responses and live long, we can develop new tactics to configure the immune systems in humans. With the understanding of robust immune responses in sharks and by knowing the genome sequence, we can also introduce the possibility of constructing better antibiotics for diseases with recombinant DNA technology. Since we now know the genome sequence and evolution of the elephant sharks, we can use this to better understand the human genome and to better understand how humans evolved as well.