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:11/21/2014)... , Nov. 20, 2014   Atmel® Corporation ... in microcontroller (MCU) and touch technology solutions, today launched ... sensors with the widest V cc range ... temperature accuracy and faster I 2 C bus communication ... serial EEPROM memory making them ideal for consumer, industrial, ...
(Date:11/18/2014)... 2014   EyeLock Inc. , a market ... MorphoTrust USA (Safran), a leading U.S. provider ... strategic partnership to offer comprehensive biometric identity solutions ... airport screening and financial services markets. ... consumers through a nationwide network of 1,100 IdentoGO® ...
(Date:11/10/2014)... began appearing on U.S. store shelves in early 2010, ... since. The small packets can be tossed into a ... liquid or powder. The convenience, though, has come with ... researchers at Nationwide Children,s Hospital found that from 2012 ... 17,230 children younger than 6 years of age swallowing, ...
Breaking Biology News(10 mins):Atmel Launches Industry's First Wide-V(cc) Low-Power Temperature Sensor Family 2Atmel Launches Industry's First Wide-V(cc) Low-Power Temperature Sensor Family 3Atmel Launches Industry's First Wide-V(cc) Low-Power Temperature Sensor Family 4EyeLock, MorphoTrust Form Strategic Partnership to Pursue Commercial Enterprise Deployments 2EyeLock, MorphoTrust Form Strategic Partnership to Pursue Commercial Enterprise Deployments 3Study finds laundry detergent pods, serious poisoning risk for children 2
(Date:11/24/2014)... Baltimore, MD (PRWEB) November 24, 2014 ... recruiting underrepresented patient populations into clinical trials at ... Maryland. , “Continental was created with the ... trials play a fundamental role in medical advances," ... the Tuskegee syphilis experiment to the immortal cell ...
(Date:11/24/2014)... Senior Vice President, General Manager for Clinical ... acumen Elsevier , a world-leading provider ... congratulates Diane Bartoli , Senior Vice President and ... Solutions, for being recognized in the 13 th ... Profiles in Diversity Journal ® . ...
(Date:11/22/2014)... Boston, MA (PRWEB) November 21, 2014 ... and key investors will gather on December 3rd ... Boston Biotech Conferences series. GeneticRx will take place ... Harvard Medical School and will discuss the present ... gene therapy, exon skipping, and gene editing—as well ...
(Date:11/22/2014)... 2014 The “Chiral Chromatography Columns ... Material (Metal, Glass, Plastic), by Application [GC, LC ... Forecast to 2018” analyses and studies the major ... America, Europe, Asia, and Rest of the World. ... figures spread through 135 pages and in-depth TOC ...
Breaking Biology Technology:At Continental Clinical Solutions, CEO Saleh Stevens Focuses on Diversity in Clinical Trial Recruitment at Maryland Site 2At Continental Clinical Solutions, CEO Saleh Stevens Focuses on Diversity in Clinical Trial Recruitment at Maryland Site 3Elsevier Clinical Solutions' Diane Bartoli Featured In Profiles in Diversity Journal's 13th Annual Women Worth Watching Issue 2Elsevier Clinical Solutions' Diane Bartoli Featured In Profiles in Diversity Journal's 13th Annual Women Worth Watching Issue 3Pioneering Academics and Key Industry Leaders to Discuss Rare Diseases and the Emergence of New Genetic Medicines at Genetic Rx on December 3rd 2Chiral Chromatography Columns Market worth $87.8 Million by 2018 - New Research Report by MarketsandMarkets 2Chiral Chromatography Columns Market worth $87.8 Million by 2018 - New Research Report by MarketsandMarkets 3Chiral Chromatography Columns Market worth $87.8 Million by 2018 - New Research Report by MarketsandMarkets 4Chiral Chromatography Columns Market worth $87.8 Million by 2018 - New Research Report by MarketsandMarkets 5
Cached News: