Navigation Links
Many a mickle makes a muckle: How changes in animals' size and shape arise
Date:6/30/2011

The transcription of genes is tightly controlled, with a bewildering array of regulatory DNA sequences interacting with a similarly large number of proteins and other factors to determine which genes are active when and where. Understanding how it all works has challenged countless molecular biologists over the past decades but we are now starting to make significant progress. Even so, we have scarcely begun to understand how the entire complexity evolves to give differences in the size and shape of organisms. Exciting new findings are now reported by the group of David Stern at Princeton University, in collaboration with Alistair McGregor of the University of Veterinary Medicine, Vienna and with Franois Payre of the Universit de Toulouse.

Stern's group is investigating the evolution of morphology in fruit flies. The larvae of two closely related flies, the widespread Drosophila melanogaster (which appear as if by magic around our fruit bowls in summer) and the more local Drosophila sechellia (which is found only on the Seychelles), differ in their patterns of hairs or "trichomes". The difference stems from changes in the expression of the wonderfully named "shaven baby" (svb) gene: svb is not expressed in certain types of cells in Drosophila sechellia and as a result their larvae lack lawns of hairs on the tops and sides of their backs.

Previous work in Stern's group had determined that differences in the DNA sequence of the svb regulatory region caused the difference between the hairy and naked species. McGregor found that particular regions of the so-called enhancer E were responsible for controlling expression of the svb gene on the top and sides of fly larvae. The sequence of E6, the part of the enhancer that activates the gene, is subtly different in Drosophila sechellia compared with other related species and two post-docs in Stern's lab, Nicols Frankel and Deniz F. Erezyilmaz, have now systematically examined the effects of each of the changes in isolation and together.

The results provide an elegant demonstration of evolution in action. At least five changes were found to contribute to the altered functional properties of the enhancer. Interestingly, none of the changes on its own has a particularly dramatic effect and the effect of all the changes together is far greater than the sums of all the individual effects. In other words, the effect of any particular change depends on what changes may already be present.

As McGregor notes, the experiments reported in the current issue of Nature represent "one of the first functional dissections of the contribution of individual nucleotide changes in an enhancer responsible for morphological evolution." The results provide a possible explanation for how individual mutations, each with relatively minor consequences, can be "fixed" in a population as a result of subsequent events, leading ultimately to the evolution of distinct morphologies.

McGregor has now left Vienna for Oxford Brookes University (UK), where he is continuing his study of the evolution of animal development and morphology.


'/>"/>

Contact: Dr. Alastair McGregor
amcgregor@brookes.ac.uk
44-784-037-2939
University of Veterinary Medicine -- Vienna
Source:Eurekalert

Related medicine news :

1. Heightened immunity to colds makes asthma flare-ups worse, U-M research shows
2. Note to dads: Good parenting makes a difference
3. Cancer Drug Avastin Makes Inroads Against Ovarian Tumors
4. U.S. Makes It Easier to Get Insurance With Pre-Existing Conditions
5. MIT research: What makes an image memorable?
6. Leopoldina makes recommendations to the G8 heads of state and government
7. ESC Policy Conference makes recommendations for new EU medical device legislation
8. Mayo Clinic studies how much practice makes perfect when performing colonoscopies
9. What Makes a Face Appealing to the Opposite Sex?
10. Why Someone Elses Gaffe Makes You Cringe
11. Cost of heart drugs makes patients skip pills, putting themselves at risk
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/31/2016)... ... , ... Spectrum Aquatics has launched a brand new ADA pool lift, the ... the user in mind. , “Over the last two years our key customers and ... lbs lift is a necessary requirement for certain facilities with specific needs,” said Nabil ...
(Date:5/31/2016)... ... May 31, 2016 , ... TeaZa® Energy, LLC ... pouches, on World No Tobacco Day . The new flavor—Tropical TeaZa? Energy—will ... on this summer. , The new flavor is best described as a juicy, ...
(Date:5/31/2016)... , ... May 31, 2016 , ... ... marketing services firm and statement solutions provider, for the tenth consecutive year ... May 2016 issue of Advertising Age, and SourceLink ranked eighteenth in the “U.S. ...
(Date:5/30/2016)... FL (PRWEB) , ... May 30, 2016 , ... As ... means for their children and their efforts to keep their households lice free. ... across Hawaii are enacting new policies that keep kids in the classroom despite the ...
(Date:5/30/2016)... , ... May 30, 2016 , ... Another ER facility ... in Plano, located at 3960 Legacy Drive, Plano, TX and is open 24 hours ... of Commerce followed by a medical open house. The Jasper High School band entertained ...
Breaking Medicine News(10 mins):
(Date:5/30/2016)... Eye expert s ... eye examination before leaving hospital ... Moorfields Eye Hospital Dubai, the first overseas branch of the ... identified premature babies as a special concern in the region when ... retinopathy of prematurity (ROP). ROP is a potentially blinding condition that ...
(Date:5/27/2016)... , May 27, 2016 ... innovative biopharmaceutical company focused on late-stage drug development, ... Dexcel Pharma of pivotal batches required for ... Drug Administration (FDA). This follows Kitov,s announcement ... III trial successfully met its primary efficacy endpoint. ...
(Date:5/26/2016)... , May 26, 2016 ... Associated With Both Cost Savings and Overall ... plc (LSE: BTG), an international specialist healthcare company, ... at the 21st Annual Meeting of ISPOR (International ... treatment of hepatocellular carcinoma (HCC) using yttrium-90 glass ...
Breaking Medicine Technology: