Navigation Links
Weizmann Institute scientists discover: A 'risk distribution law' for evolution

Prof. Naama Barkai will receive the Helen and Martin Kimmel Award for Innovative Investigation on Monday, Nov. 5 at the Weizmann Institute. The award is accompanied by a research grant of a million dollars over five years.

Taking a chance on an experiment this is one of the impulses that drive evolution. Living cells are, from this angle, great subjects for experimentation: Changes in one molecule can have all sorts of interesting consequences for many other molecules in the cell. Such experiments on genes and proteins have led the cell, and indeed all life, on a long and fascinating evolutionary journey.

Prof. Naama Barkai of the Weizmann Institutes Molecular Genetics Department recently took a look at gene expression the process in which the encoded instructions are translated into proteins and the evolution of mechanisms in the cell for controlling that expression. Changes in genes, and thus in protein structure, are a double-edged sword: They can give cells new abilities or advantages for survival, but they can also spell disease or death for the organism. Not all genes evolve at the same rate. Indeed, some have been conserved through long stretches of evolution: Similar versions of some genes are found in yeast, plants, worms, flies and humans. When do cells hold on to specific gene sequences, and when do they allow evolution to experiment with them"

Clearly, highly conserved genes fulfill some basic, universal function for all life, and changes in their sequences have drastic consequences, involving death or the inability to multiply. How does evolution 'decide' which genes need to be conserved, and which it can change freely" What keeps these genes safe from the ongoing experimentation thats constantly carried out on other genes"

Barkai and her team discovered a sort of 'risk distribution law' for evolution. They found that a genetic 'phrase' that regularly shows up in the promoter region of genes (the bit of genetic code responsible for activating the gene) contains a key to gene conservation: The expression of a gene that contains the sequence TATA in its promoter is more likely to have evolved than that of a gene that does not have TATA in its promoter. In other words, the level of risk appears to written in the genetic code, in a way thats similar to financial risk analysis: When the cost of error is high, an investors willingness to chance the risk is low, but if the cost of a mistake is negligible, even if the chance of making one is high, the possibility of gain may make the risk worthwhile. Evolution, it seems, discovered this principle millions of years before Wall Street.

In a different study, Barkai and her research team investigated the effects of a drastic evolutionary experiment that nature sometimes performs on living cells: the doubling of an entire genome. They looked at two related species of yeast, one of which (S. cerevisiae) had undergone genome doubling millions of years ago. After the duplication, Cerevisiae seem to have learned a new trick: They gained the ability to grow and multiply without oxygen.

To find out if this difference is connected to changes in gene expression, the team tested 50 genes that play a role in processing oxygen in both species. They discovered one gene segment a bit responsible for expression of these genes that had changed in the course of the genome doubling in cerevisiae. The effects of this change were seen in over 50 genes and dramatically affected the oxygen requirements of the yeast.

The ability to live without oxygen might give cerevisiae a clear advantage over its sister yeast if there were a radical change in the make-up of the Earths atmosphere. But it is exactly this combination of environmental change and genetic experimentation that has fueled evolution for millions of years and is still driving it today.


Contact: Yivsam Azgad
Weizmann Institute of Science

Related biology news :

1. Weizmann Institute scientists develop a new approach for directing treatment to metastasized prostate cancer in the bones.
2. Weizmann Institute suggests that immune cells help to maintain cognition and brain cell renewal
3. Weizmann Institute scientists discover a molecular security mechanism for keeping mutations in check
4. Weizmann Institute scientists develop a general control switch for protein activity
5. Affymetrix and the Karolinska Institutet Announce Translational Medicine Strategic Alliance
6. UCLA launches $20 million stem cell institute to investigate HIV, cancer and neurological disorders
7. BioMed Central welcomes the new National Institutes of Health public access policy
8. Institute for Systems Biology Symposium Addresses Need for Better Computational Tools
9. Virginia Tech, Nanjing Institute researchers discover half-billion year-old fossils
10. UC San Diego partners with Venter Institute to build marine microbial genomics cyberinfrastructure
11. Virginia Bioinformatics Institutes launches microbial database
Post Your Comments:
(Date:11/10/2015)... 10, 2015  In this report, the ... of product, type, application, disease indication, and ... report are consumables, services, software. The type ... biomarkers, efficacy biomarkers, and validation biomarkers. The ... diagnostics development, drug discovery and development, personalized ...
(Date:11/2/2015)... Calif. , Nov. 2, 2015  SRI International ... million to provide preclinical development services to the National ... contract, SRI will provide scientific expertise, modern testing and ... variety of preclinical pharmacology and toxicology studies to evaluate ... --> The PREVENT Cancer Drug Development Program ...
(Date:10/29/2015)... , Oct. 29, 2015  Connected health pioneer, ... driving the explosion of technology-enabled health and wellness, and ... new book, The Internet of Healthy Things ... sensors or smartphones even existed, Dr. Kvedar, vice president, ... of health care delivery, moving care from the hospital ...
Breaking Biology News(10 mins):
(Date:11/27/2015)... November 27, 2015 ... popularity of companion diagnostics is one of ... market with pharmaceutical companies and diagnostic manufacturers ... tests. . --> ... report on global cancer biomarkers market spread ...
(Date:11/25/2015)... , Nov. 25, 2015  PharmAthene, Inc. (NYSE MKT: ... adopted a stockholder rights plan (Rights Plan) in an ... loss carryforwards (NOLs) under Section 382 of the Internal ... --> PharmAthene,s use of its NOLs could be ... as defined in Section 382 of the Code. In ...
(Date:11/25/2015)... , Nov. 25, 2015  Neurocrine Biosciences, Inc. ... Gorman , President and CEO of Neurocrine Biosciences, will ... Conference in New York . ... visit the website approximately 5 minutes prior to the ... replay of the presentation will be available on the ...
(Date:11/25/2015)... PORTLAND, Oregon , November 25, 2015 /PRNewswire/ ... Deep Market Research Report is a professional and ... Genomics industry.      (Logo: ... basic overview of the industry including definitions, classifications, ... analysis is provided for the international markets including ...
Breaking Biology Technology: