About Careers Internship MedBlog Contact us
Medindia LOGIN REGISTER
Advertisement

Researchers Find Genetic Link To How Birds And Mammals Evolved To Have Four-Chambered Hearts

by Aruna on September 7, 2009 at 9:32 AM
Researchers Find Genetic Link To How Birds And Mammals Evolved To Have Four-Chambered Hearts

The first genetic link that can explain how the heart evolved from being a three-chambered to four-chambered organ has been discovered by scientists.

The discovery has shed light on how cold-blooded birds and mammals became warm-blooded.

Advertisement

Frogs have a three-chambered heart consisting of two atria and one ventricle, which sends a concoction of blood that is not fully oxygenated to the rest of the frog's body.

On the other hand, turtles' hearts have three chambers, but the single ventricle starts developing a wall, or septum, which makes the heart send blood that is slightly richer in oxygen than the frog's.
Advertisement

However, birds and mammals have a fully septated ventricle-a bona fide four-chambered heart, which ensures the separation of low-pressure circulation to the lungs, and high-pressure pumping into the rest of the body.

As warm-blooded animals, we use a lot of energy and therefore need a great supply of oxygen for our activities. The four-chambered heart gives us an evolutionary advantage, we're able to roam, hunt and hide even in the cold of night, or the chill of winter.

But many humans suffer from congenital heart disease, a very common birth defect, which is usually caused by VSD, or ventricular septum defects-a condition that is frequently correctable with surgery.

Benoit Bruneau of the Gladstone Institute of Cardiovascular Disease, who studies the transcription factor, Tbx5, in early stages of embryological development, has called it "a master regulator of the heart."

He teamed up with scientists at Michigan State University to examine a wide evolutionary spectrum of animals and found that in the cold-blooded, Tbx5 is expressed uniformly throughout the forming heart's wall.

On the other hand, warm-blooded embryos showed the protein very clearly restricted to the left side of the ventricle, which allowed for the separation between right and left ventricle.

Interestingly, in the turtle, the molecular signature was found to be transitional as well.

A higher concentration of Tbx5 is found on the left side of the heart, gradually dissipating towards the right.

"The great thing about looking backwards like we've done with reptilian evolution is that it gives us a really good handle on how we can now look forward and try to understand how a protein like Tbx5 is involved in forming the heart and how in the case of congenital heart disease its function is impaired," concluded Bruneau.

Source: ANI
ARU
Font : A-A+

Advertisement

Advertisement
Advertisement

Recommended Readings

Latest Research News

Brain Circuits That Shape Bedtime Rituals in Mice
New study sheds light on the intrinsic, yet often overlooked, role of sleep preparation as a hardwired survival strategy.
NELL-1 Protein Aids to Reduce Bone Loss in Astronauts
Microgravity-induced bone loss in space, can be reduced by systemic delivery of NELL-1, a protein required for bone growth and its maintenance.
Connecting Genetic Variants to the Alzheimer's Puzzle
Researchers establish connections between Alzheimer's-linked genetic alterations and the functioning of brain cells.
Gene Therapy Sparks Spinal Cord Regeneration
Team at NeuroRestore introduces a groundbreaking gene therapy that has effectively promoted nerve regrowth and reconnection, post spinal cord injury.
Unlocking the Gut Microbiome's Influence on Bone Density
Scientists aim to pinpoint particular functional pathways affected by these bacteria that may have an impact on skeletal health.
View All
This site uses cookies to deliver our services.By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use  Ok, Got it. Close
MediBotMediBot
Greetings! How can I assist you?MediBot
×

Researchers Find Genetic Link To How Birds And Mammals Evolved To Have Four-Chambered Hearts Personalised Printable Document (PDF)

Please complete this form and we'll send you a personalised information that is requested

You may use this for your own reference or forward it to your friends.

Please use the information prudently. If you are not a medical doctor please remember to consult your healthcare provider as this information is not a substitute for professional advice.

Name *

Email Address *

Country *

Areas of Interests