Hot New Field

Innate immunity has become a very hot topic in the Drosophila research community, especially in regards to aging research. Recently, it was found that exposing young fruit flies to bacteria actually extends lifespan, and if flies are kept in axenic conditions to for their entire lifespan, they actually live shorter. The paper can be found here.

Flies were initially raised in axenic conditions were short lived, however, lifespan can be returned to normal or extended depending on when they are exposed to bacteria. Non-axenically rasied embryos transferred to sterile food at various stages of adult life indicate that the first two days of adult life are hugely important in extending mean lifespan. Similarly, axenically rasied embryos transferred to non-sterile food before two days old show the greatest increase in mean lifespan.

To test the effect of genetic makeup in the flies, similar experiments were conducted on an array of long lived mutants. A spectrum of results was seen, from no lifespan extension, to large lifespan extension, indicating that it is possible to dissect the response using mutants.

When these results are discussed in light of similar findings in other model organisms, it is suggested by the authors that a likely reason for the need for bacteria early in life is to aide in gut developement, and the establishment of an internal gut flora.