New genes as vital to life as old ones

LONDON - Contrary to what most experts previously thought, genes do not have to be old to be vital for life. Even genes that evolved only one million years ago - just a blink in evolutionary terms - can have critical roles, a study has shown.

It has long been assumed that the ‘bread and butter’ genes most important to life have been handed down from species to species since ancient times, reports the journal Science.

Newer genes were thought to have altered the ‘flavour’ but not the substance of core biology, according to the Daily Mail.

This view has now been challenged after scientists individually ’silenced’ more than 200 ‘new’ genes in fruit flies and found that in over 30 percent of cases the flies died.

The US study showed that new genes were just as crucial to development and survival as old genes.

Manyuan Long from the University of Chicago who led the research said: “New genes are no longer just vinegar, they are now equally likely to be butter and bread. We were shocked.”

The scientists used a technique called RNA interference to stop genes passing on their coded instructions for building proteins.

Of 195 young genes tested, 59 were vital to life. Knocking any one of them out caused the fly to die during development. When the same treatment was given to old genes, the proportion found to be lethal when silenced was about the same, 86 out of 245.

The young genes tested only appeared between one and 35 million years ago.

Deleting many of the new genes killed flies during middle or late stages of development, while old genes affected earlier stages.

Co-author Sidi Chen said: “If our intuition is correct, some important health information for humans will reside in unique parts of the human genome.”