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:


(Date:11/28/2016)... , Nov. 28, 2016 ... a rate of 16.79%" The biometric system market ... grow further in the near future. The biometric system ... billion in 2022, at a CAGR of 16.79% between ... system, integration of biometric technology in smartphones, rising use ...
(Date:11/21/2016)... 2016   Neurotechnology , a provider of ... announced that the MegaMatcher On Card fingerprint matching ... the NIST Minutiae Interoperability Exchange (MINEX) III ... steps of the evaluation protocol. ... of fingerprint templates used to establish compliance of ...
(Date:11/16/2016)... SANTA CLARA, Calif. , Nov. 16, 2016 /PRNewswire/ ... company enhancing user experience and security for consumer ... provider for the financial and retail industry, today ... more secure and convenient way to authenticate users ... now uses Sensory,s TrulySecure™ software which ...
Breaking Biology News(10 mins):
(Date:12/2/2016)... York, NY (PRWEB) , ... December 01, 2016 , ... ... event is expanding to three days and will take place on February 1-3, 2017 ... (GSK) and Dr James Gulley (NCI), the program provides a unique 360-degree approach, which ...
(Date:12/2/2016)... , Dec. 1, 2016   SurePure, Inc. ... announced today that the Company has concluded an agreement ... right for a 90-day period to acquire units of ... of approximately USD 3.7 million.  Concurrently ... with Tamarack under which Tamarack will seek regulatory approvals ...
(Date:11/30/2016)... 2016 The global Pyrogen Testing ... a dominant share in the overall market. The leading ... and Merck KGaA, held a lion,s share of 51% ... observes that these companies are expected to retain their ... are do not require rabbit pyrogen testing along with ...
(Date:11/30/2016)...  Tempus, a technology company focused on supporting ... Cancer Center have partnered to better determine which ... treatment based on next generation genomic and transcriptomic ... research collaboration, Tempus will provide sequencing and analysis ... to Penn. Utilizing next-generation sequencing, machine learning and ...
Breaking Biology Technology:
Cached News: