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:3/17/2016)... , March 17, 2016 ABI Research, ... forecasts the global biometrics market will reach more ... 118% increase from 2015. Consumer electronics, particularly smartphones, ... fingerprint sensors anticipated to reach two billion shipments ... Dimitrios Pavlakis , Research Analyst at ABI ...
(Date:3/14/2016)... March 14, 2016 NXTD ) ("NXT-ID" ... commerce market, announces the airing of a new series of ... week of March 21 st .  The commercials will air ... popular Squawk on the Street show. --> NXTD ... growing mobile commerce market, announces the airing of a new ...
(Date:3/11/2016)... PUNE, India , March 11, 2016 ... to a new market research report "Image Recognition Market ... by Application (Marketing and Advertising), by Deployment Type (On-Premises ... Global Forecast To 2022", published by MarketsandMarkets, the global ... in 2015 to USD 29.98 Billion by 2020, at ...
Breaking Biology News(10 mins):
(Date:4/29/2016)... ... 2016 , ... Intelligent Implant Systems announced today that the two-level components for ... the United States. These components expand the capabilities of the system and allow ... in October of 2015, the company has seen significant sales growth in 1Q 2016, ...
(Date:4/28/2016)... -- The report "Cryocooler Market by Type ... Support, Product Repairs & Refurbishment, Preventive Maintenance, and Customer ... published by MarketsandMarkets, the global market is expected to ... CAGR of 7.29% between 2016 and 2022. ... spread through 159 Pages and in-depth TOC on  "Cryocooler ...
(Date:4/28/2016)... Rocky Hill, Conn. (PRWEB) , ... April 28, ... ... source of financing and ongoing support for Connecticut's innovative, growing companies, today announced ... early-stage digital health and financial technology (fintech) companies. , “VentureClash looks ...
(Date:4/28/2016)... ... April 28, 2016 , ... ... investments in recruiting top industry experts, and expanding its LATAM network and logistics ... tools for clients to manage their clinical trial projects. , The expansion will ...
Breaking Biology Technology:
Cached News: