Genetic instructions for developing limbs and digits were present in primitive fish millions of years before their descendants first crawled on to land, researchers have discovered.
Genetic switches control the timing and location of gene activity. When a particular switch taken from fish DNA is placed into mouse embryos, the segment can activate genes in the developing limb region of embryos, University of Chicago researchers report in Proceedings of the National Academy of Sciences. The successful swap suggests that the recipe for limb development is conserved in species separated by 400 million years of evolution.
"The genetic switches that drive the expression of genes in the digits of mice are not only present in fish, but the fish sequence can actually activate the expression in mice," said Igor Schneider, PhD, postdoctoral researcher in the Department of Organismal Biology and Anatomy at the University of Chicago and lead author on the paper. "This tells us how the antecedents of the limb go back in time at every level, from fossils to genes."
The genetic hunt was inspired by a famous fossil find the 2004 discovery of the transitional fossil Tiktaalik in the Canadian Arctic by a team led by Neil Shubin of the University of Chicago. A transitional species between fish and the four-legged tetrapods, Tiktaalik possessed fins containing a skeletal structure similar to the limbs of later land-dwelling animals.
Those similarities particularly the wrist and hand-like compartments present in the fins of Tiktaalik and its peers inspired a laboratory experiment to look at the homology, or shared physical and genetic traits, of fish and limbed animals.
"This is really a case where knowing something about the fossils and the morphology led us to think about genetic experiments," said Shubin, PhD, the Robert R. Bensley Professor of Organismal Biology and Anatomy and senior author of the study. "Tiktaalik and i
'/>"/>
| Contact: Robert Mitchum robert.mitchum@uchospitals.edu 773-795-5227 University of Chicago Medical Center Source:Eurekalert |
Related biology news :
1. New genetic clues for schizophrenia
2. Unlocking the genetics and biology of ankylosing spondylitis
3. University of Houston researcher an author of multi-institutional genetic study of ovarian cancer
4. Evolution and domestication of seed structure shown to use same genetic mutation
5. Early embryos can correct genetic abnormalities during development
6. Genetic variant linked to development of liver cancer in hepatitis C virus carriers
7. Geneticist receives Excellence in Science Award from coalition of biomedical researchers
8. Adult stem cells carry their own baggage: Epigenetics guides stem cell fate
9. More than bacon: Genetic alterations in pig tissue may allow for human transplantation
10. Genetic conductor involved with new brain cell production in adults
11. Genetic testing for inherited cardiac conditions is patchy in Europe
 |
| Copyright © 2003-2012 Bio-Medicine. All rights reserved. ABOUT | CONTACT US | DISCLAIMER | PRIVACY POLICY | TERMS AND CONDITIONS |  |