LATEST UPDATES » Christmas Edition: What's your 360o View?       » Hong Kong-Swiss joint medical researchers to fight Cancer       » New agreement launches collaboration between New Zealand and China in Medical Science       » Gait recorded by Smart Phone reveals Your Emotion       » What to expect in year 2050?       » International Mountain Day: Are we making a mountain out of a molehill?      
Elephant shark genome provides new insights into bone formation and adaptive immunity in humans
Scientists at A*STAR's Institute of Molecular and Cell Biology (IMCB) led an international team of researchers that sequenced and analyzed the genome of the elephant shark. A comparison of the elephant shark genome with human and other vertebrate genomes revealed why the skeleton of sharks consists entirely of cartilage instead of bones. The findings carry potential implications for human bone disease treatment. The analysis also sheds new light on the origin of the adaptive immune system.

The collaboration with 12 international institutions was headed by IMCB's Prof Byrappa Venkatesh, who is also a chairperson of the "Genome10K" Project. The project was largely funded by the National Institutes of Health (NIH), USA, the world's foremost center for the support of biomedical research.

Analysis of the elephant shark genome

Elephant shark is a member of cartilaginous fishes, which are the oldest living group of jawed vertebrates that diverged from bony vertebrates about 450 million years ago. Cartilaginous fishes include sharks, rays, skates and chimaeras. Unlike humans and other bony vertebrates, cartilaginous fishes are unable to replace cartilage with bone. Among over 1,200 species of cartilaginous fishes, the elephant shark was sequenced due to its compact genome size. Analysis of the elephant shark genome identified a family of genes absent in elephant shark but present in all bony vertebrates. A significant reduction in bone formation was observed when a member of this gene family was knocked out in zebrafish, thereby indicating the importance of this gene family in bone formation. The finding has important implications towards our understanding of bone-related diseases such as osteoporosis and hence the development of effective therapeutic strategies for them.

An unexpected finding was that elephant shark appears to lack special types of immune cells previously considered essential for defense against viral/bacterial infections and preventing autoimmune reactions such as diabetes and rheumatoid arthritis. Despite this seemingly primitive organization of the immune system, sharks exhibit robust immune defenses and are long-lived. By challenging long-held notions, this discovery has opened up a new avenue towards the development of non-intuitive strategies to shape the immune functions of humans.

The study also found that the elephant shark genome is the slowest evolving among all vertebrates, including the coelacanth, popularly known as a "living fossil", whose genes were recently shown to be evolving slower than those of other bony vertebrates. Furthermore, large blocks of elephant shark and human chromosomes were found to be highly similar. The markedly slow evolution of the elephant shark genome and its similarity to the human genome, further underscores its importance as a reference genome for comparative genomic studies aimed at better understanding of the human genome.

Professor Byrappa Venkatesh, Research Director at IMCB added, "The slow evolving genome of the elephant shark is probably the best proxy for the ancestor of all jawed-vertebrates that became extinct a long time ago. It is a cornerstone for improving our understanding of the development and physiology of human and other vertebrates as illustrated by our analysis of the skeletal system and immune system genes."

Dr. Wes Warren, senior author of the study's paper commented, "Although cartilaginous vertebrates and bony vertebrates diverged about 450 million years ago, with the elephant shark genome in hand, we can now begin to identify key genetic adaptations in the evolutionary tree."

Professor Hong Wanjin, Executive Director of IMCB, said, "Over the years, IMCB has carried out several remarkable genomic projects and we are excited to showcase yet another milestone. Not only has our research team sequenced the first shark-family member genome, they have also uncovered many insights significant to the field of genomic and medical research through the genome analysis."

Professor Sir David Lane, Chief Scientist at A*STAR, said, "We are delighted that a Singapore laboratory conceived and led a major international genome project. The international research grant from NIH, USA is a testimony of Singapore's world-class standard in genomics research."

Click here for the complete issue.

news Nanyang Technological University Smart Chip tells you how healthy your battery is
news Mechanobiology Institute, Singapore (MBI) and Cancer Science Institute of Singapore (CSI) at National University of Singapore
news The Future of Cities - A collaboration between Channel NewsAsia (Perspectives) and Newcastle University

Christiana Figueres on COP21 Paris and the World's Response to Climate Change click here.

APBN Editorial Calendar 2015
Trends and Predictions for 2015
Robotics in Healthcare
April & May:
Universal Health Coverage
Start-Up Biotech Companies
Preventative and Translational Medicine
ASEAN Economic Community and Asia's Life Sciences Industry
Big Data: Healthcare and Drug Development
Clear Air
December (Christmas Edition):
What's your 3600 view?
APBN Editorial Calendar 2016
Korea's Biotechnology Industry
Antibody Engineering in Japan
Life-Saving Opportunities: A Guide to Regenerative Medicine
Tobacco Smoking: The 'Real' Cost of One Cigarette
Medical Devices and Technology
Occupational Health
Water Technology
Olympics: Evolution of Sports
Respiratory: Seasonal flu viruses
About Us
Available issues
Editorial Board
Letters to Editor
Instructions to Authors
Advertise with Us
Editorial calendar is subjected to changes. – Editor: Yuhui N Lin
World Scientific Publishing Co. Pte. Ltd.
5 Toh Tuck Link, Singapore 596224
Tel: 65-6466-5775
Fax: 65-6467-7667
» Editorial Enquiries: biotech_edit@wspc.com
» For Subscriptions, Advertisements &
   Media Partnerships Enquiries:
   Ms PoPo Kwok or Ms Sok Ching Lim
Copyright© 2015 World Scientific Publishing Co Pte Ltd  •  Privacy Policy