These are the agents that switch genes on or off in the cell.

With the new drugs, researchers have successfully switched genes on and off at will in animal experiments.

But switching genes around strikes me as little more than expedited breeding.

Trying to switch genes on and off is even more difficult, and such switches tend to weaken over time.

If it senses a new food, it can switch genes on and off to alter its metabolism.

Are behaviors and organs constructed in much the same way, each with a master switch gene that controls a network of lower level genes?

They can switch genes on and off in complex patterns to control where and when they make proteins.

Gene regulation switches genes on and off, and so controls cell differentiation, and morphogenesis.

The researchers were inspired by the shapes of these molecules, and convinced that they could be used in a complex system to switch genes on and off.

This natural method of switching genes off has turned out to be a superb research tool, allowing scientists to understand the role of new genes by suppressing them.

The normal gene specifies a protein that from its design motifs looks as if it is meant to slip into the nucleus of the cell and switch genes on or off.

What all these pills will have in common, if they ever see the light of day, is that they will confer health by switching genes on and off with unprecedented precision.

It is hoped that using a 'master switch gene' will result in more stable vessels, because the processes by which they are formed would resemble more closely those of normal vessel development.

People who know about such things say Dr. Xu's work could affect all our lives, making it possible to switch genes on and off, facilitating therapies for diabetes, depression, you name it.

Her father believed that sometimes it was life-cycle changes like adolescence, puberty, pregnancy, menopause, that switched genes on and off - and sometimes it was external influences, such as pollution, stress, trauma.

In plants the SRA-YDG domain is associated with the SET domain, found in a family of histone methyl transferases, which switch genes "off" by adding a methyl group.

The researchers say that by identifying a master switch gene for the formation of a flower's reproductive organs - the plant parts that provide most of the world's food - the new results will be of particular interest to agricultural scientists.

When his last affinity command activated them, each organelle released a batch of plasmids (small, artificially synthesised DNA loops) and a considerable quantity of transcription factors, proteins capable of switching genes on or off.

Although researchers now have evidence in hand that both Leafy and Apetala1 can act on their own as master switch genes that can set flowering in motion, it remains unclear how exactly these two genes normally interact in their high-level genetic managing.

Using a master switch gene Another approach that addresses the involvement of multiple factors in therapeutic angiogenesis is the use of a so-called 'master switch gene' of angiogenesis, such as HIF-1α [ 52].

These experiments show not only how a pathway can evolve, but also, importantly, how X:A and heterogametic GSD systems can be interconverted by modifying the cue that regulates a conserved molecular switch gene (the splicing of tra mRNA).

Of course, switching on and off of genes does not in itself result in developmental change; switching genes on and off acts by changing which proteins are made and this in turn alters cell behaviour by pathways that, to repeat, may be quite tortuous.

Methylation is now generally recognised as one way of switching genes off, and is particularly interesting one because it helps to explain a crucial but mystifying fact of multicellular life - the differentiation of the genetically identical cells of an embryo into the many different tissues of the mature organism.