HOME >> BIOLOGY >> NEWS
Scientists uncover new clues to limb formation (and loss) in some sea mammals

Researchers from the Northeastern Ohio Universities College of Medicine have revealed the genetic basis behind one of the best-documented examples of evolutionary change in the fossil record: how whales lost their hind limbs.

Writing in this week's Proceedings of the National Academy of Sciences (PNAS), Hans Thewissen and his colleagues report that ancient whales--four-footed land animals not unlike large modern dogs--evolved into graceful, streamlined swimmers through a series of small genetic changes during the whales' embryonic development.

"Their research has implications for how evolution acts to create dramatic changes in an organism's body," said Richard Lane, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research.

"The findings emphasize the synergistic role traditional paleontology and evolutionary and developmental biology play at the frontiers of the evolutionary sciences," said Lane.

Thewissen and his colleagues began by exploring the embryonic development of whales' cousins, the dolphins. These creatures are intriguing because for a brief time during development they do sprout hind limbs, which quickly vanish again as the embryos reach the second month in a gestation period that lasts about 12 months.

Why? In most mammals, explains Thewissen, "a series of genes is at work at different times, delicately interacting to form a limb with muscles, bones, and skin. The genes are similar to the runners in a complex relay race, where a new runner cannot start without receiving a sign from a previous runner."

In dolphins, however, at least one of the genes drops out early in the race, disrupting the genes that were about to follow it. That causes the entire relay to collapse, ultimately leading to the regression of the animals' hind limbs. By analyzing dolphin embryos, Thewissen showed that the dropout is a gene called "Sonic Hedgehog," which is important
'"/>

Contact: Cheryl Dybas
cdybas@nsf.gov
703-292-7734
National Science Foundation
22-May-2006


Page: 1 2

Related biology news :

1. Scientists show that mitochondrial DNA variants are linked to risk factors for type 2 diabetes
2. Scientists prove that disputed Korean stem cell line comes from an unfertilized egg and not cloning
3. Scientists move closer to bio-engineered bladders
4. Scientists find stem cell switch
5. Scientists discover new way to study nanostructures
6. Scientists a step closer to understanding how anaesthetics work in the brain
7. Scientists to make news at Computational Biology Conference
8. Accident-prone? Scientists link brain function to knee injuries
9. Scientists take next step in understanding potential target for ovarian cancer treatment
10. Scientists find brown fat master switch
11. Scientists identify 2 distinct Parkinsons networks

Post Your Comments:
*Name:
*Comment:
*Email:
TAG: Scientists uncover new clues limb formation and loss some sea mammals

(Date:10/31/2014)... emits over a wide part of the electromagnetic spectrum ... built in Lund, Sweden. The MAX IV facility presents ... together its component parts in a storage - ring ... a few hundred metres. Nevertheless, if these various challenges ... experiments that require source brightness and transverse coherence will ...
(Date:10/31/2014)... Ebola one important hurdle has just been cleared – ... of North Carolina at Chapel Hill and colleagues have ... be infected with Ebola and display symptoms similar to ... current issue of Science , will significantly improve ... desperately needed to curb the worldwide public health and ...
(Date:10/31/2014)...  HITLAB SM , a healthcare innovation and ... HITLAB Innovators Summit SM on December 1, ... partner with the Clinton Foundation,s Health Matters Initiative, ... Business School Alumni Club of New ... Operations Research, bringing together leaders in healthcare and ...
Breaking Biology News(10 mins):A new generation of storage -- ring 2Improved mouse model will accelerate research on potential Ebola vaccines, treatments 2HITLAB Announces Inaugural HITLAB Innovators Summit 2HITLAB Announces Inaugural HITLAB Innovators Summit 3
(Date:10/30/2014)... , October 30, 2014 Investor-Edge ... Inc. (NYSE MKT: ONVO), Medivation Inc. (NASDAQ: ... Synthetic Biologics Inc. (NYSE MKT: SYN), and Ironwood Pharmaceuticals ... can be accessed at: http://investor-edge.com/register . ... at 4,549.23, down 0.33%, the Dow Jones Industrial Average ...
(Date:10/30/2014)... 29, 2014 Global polyvinyl chloride (PVC) ... economic crisis during 2008-2009, especially in North America and ... currently is keeping to a growing trend. , The ... utilized in the construction segment. In 2013, the key ... tubing, sheets and rigid film. Moreover, the PVC was ...
(Date:10/30/2014)... (PRWEB) October 30, 2014 On ... Cellular Medicine Showcase in Chicago, leading applied stem ... Surgeon, Dr. Wade McKenna presented talks on New ... Orthopedic Surgical Applications For Stem Cells. , Dr. ... membrane and the properties of AlphaGEMS that include: ...
(Date:10/30/2014)... CA (PRWEB) October 30, 2014 ... today that they have manually curated public data source ... non profit customers. the data is now available ... curates and unifies public and internal data sources for ... and knowledge out of the data that becomes more ...
Breaking Biology Technology:Biotech Equities Movers and Shakers - Organovo Holdings, Medivation, Pharmacyclics, Synthetic Biologics, and Ironwood Pharma 2Biotech Equities Movers and Shakers - Organovo Holdings, Medivation, Pharmacyclics, Synthetic Biologics, and Ironwood Pharma 3Biotech Equities Movers and Shakers - Organovo Holdings, Medivation, Pharmacyclics, Synthetic Biologics, and Ironwood Pharma 4Biotech Equities Movers and Shakers - Organovo Holdings, Medivation, Pharmacyclics, Synthetic Biologics, and Ironwood Pharma 5Global Polyvinyl Chloride Demand Is on Upward Trend Now, Says Merchant Research & Consulting in Its Topical Study 2Global Polyvinyl Chloride Demand Is on Upward Trend Now, Says Merchant Research & Consulting in Its Topical Study 3Riordan-McKenna Institute Founders, Neil Riordan, PhD and Orthopedic Surgeon, Dr. Wade McKenna Present at the Mid American Regenerative and Cellular Medicine Showcase 2Riordan-McKenna Institute Founders, Neil Riordan, PhD and Orthopedic Surgeon, Dr. Wade McKenna Present at the Mid American Regenerative and Cellular Medicine Showcase 3Riordan-McKenna Institute Founders, Neil Riordan, PhD and Orthopedic Surgeon, Dr. Wade McKenna Present at the Mid American Regenerative and Cellular Medicine Showcase 4Rancho BioSciences Manually Curated TCGA Data Sets Available 2
Cached News: