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:11/3/2014)... Research and Markets has announced the addition of a ... to their offering. This report describes ... started to play an important role in the practice of ... bone marrow transplants. Role of cells in drug discovery is ... of medical practice. Stem cells are discussed in ...
(Date:11/3/2014)... birth weight and preterm birth are linked to increased ... published in the American College of Rheumatology (ACR) journal, ... birth weight and pre-term babies were not at greater ... , According to the ACR, 27 million Americans ... OA. Symptoms of OA range from mild to severe ...
(Date:11/2/2014)... was fascinating to put a flashlight up to our ... Washington University in St. Louis engineers are using a ... to improve imaging of cancerous tissues and to develop ... K. Beare Distinguished Professor of Biomedical Engineering at the ... novel time-reversal technology that allows researchers to better focus ...
Breaking Biology News(10 mins):Global Cell Therapy - Technologies, Markets and Companies: 2014 Report 2Global Cell Therapy - Technologies, Markets and Companies: 2014 Report 3Preterm, low birth-weight babies may need new hips in adulthood 2Improving imaging of cancerous tissues by reversing time 2
(Date:11/26/2014)... Bio-Techne Corporation (NASDAQ: TECH ) announced today ... serve in a newly created position of Senior Vice ... be responsible for managing the operations of Bio-Techne,s Protein ... in July 2014 and the recently acquired CyVek business. ... ProteinSimple develops and commercializes proprietary systems and consumables that ...
(Date:11/26/2014)... 25, 2014  Roka Bioscience, Inc. (NASDAQ: ROKA ... solutions for the detection of foodborne pathogens, today announced that ... Jaffray  26 th Annual Healthcare Conference on December 2, ... The New York Palace in New York, NY ... concerning the Company, its operations, strategies and prospects may be ...
(Date:11/24/2014)... , UAE, November 24, 2014 ... Hamdan Bin Rashid Al Maktoum Awards for Medical Sciences", ... Dubai, United Arab Emirates , on 15 ... ) , The Carter Center which won ... is actively involved in numerous programs that aim to ...
(Date:11/24/2014)... Belgium , Nov. 24, 2014 ... focused on developing diagnostic tests for cancer and other conditions, ... will be presented at the Science for Business BioWin Day ... Belgium . The data come from VolitionRx,s lung cancer ... Pneumology department of the Centre Hospitalier Universitaire (CHU) de Liege ...
Breaking Biology Technology:Bio?Techne Announces Appointment Of Robert Gavin As Leader Of New Protein Platforms Division 2Bio?Techne Announces Appointment Of Robert Gavin As Leader Of New Protein Platforms Division 3Roka Bioscience to Present at the Piper Jaffray Healthcare Conference 2Five US Winners Among Recipients of Hamdan Medical Awards 2VolitionRx to Present Positive Data from Pilot Lung Cancer Study at BioWin Day 2014 2VolitionRx to Present Positive Data from Pilot Lung Cancer Study at BioWin Day 2014 3VolitionRx to Present Positive Data from Pilot Lung Cancer Study at BioWin Day 2014 4VolitionRx to Present Positive Data from Pilot Lung Cancer Study at BioWin Day 2014 5VolitionRx to Present Positive Data from Pilot Lung Cancer Study at BioWin Day 2014 6
Cached News: