Drosophila, again!

Classical genetics owe quite a lot to Drosophila melanogaster, the little fruit flies that have been a major tool in our understanding of the subject.

More than a century has passed since the first Drosophila research paper was published by Dr Thomas Hunt Morgan from a work done in his famous ‘Fly Room’ at Columbia University. Morgan and colleagues would painstakingly check on thousands of flies with a magnifying glass, but finally were the first ones to confirm that genes are located on chromosomes, like beads on a string.

Morgan, who went on to get Nobel Prize for all his work in the Fly Room was not the first scientist to work with Drosophila, but his work ensured a lot of limelight for the bugs. These flies are great to work with and much easier to take care of in the lab, unlike the rats and rabbits. And all that they need is a little artificial media to keep their tummies full.

They are small organisms, so small that they can be kept in huge numbers in little vials in the lab, but no, not so small that you need a microscope to see them. To knock them unconscious, all that is needed is a little carbon dioxide, and by the time you write down your observations, they are up and about, without any side effects.

Drosophila recently got into news again. This time, the connection was Indian, so very Indian. A group of scientists, including Dr M S Valiathan, studied the effect of Ayurvedic medicines such as ‘Amalaki Rasayana’ and ‘Rasa Sindoor’ on the fruit flies. They were looking for the effects on longevity, development, fertility and stress-tolerance, among others.

The team, that included Vibha Dwivedi, Mousumi Mutsuddi and S C Lakhotia from Banaras Hindu University; E M Anandan, Rajesh S Mony and T S Muraleedharan from Arya Vaidya Sala, Kottakkal; and Dr Valiathan from Manipal University, picked two different categories of formulations for the study - a ‘rasayana’ and a ‘bhasma.’

The Amalaki Rasayana is a herbal derivative prepared from fruits of amla or Indian gooseberry and the Rasa Sindoor is a bhasma, an organometallic derivative of mercury. The bhasma does not contain active metal. The metal is converted into ash or oxide and is in the form of an organometallic compound.

A significant finding of the study was that food supplemented with Rasa Sindoor did not show any evidence of heavy-metal toxicity in the larvae or flies. Neither did it cause any lethality or developmental defects in the emerging flies. It appears that the processing of mercury in the specified Ayurvedic manner seems to convert mercury sulphide to nano particles.

However, the most important result was the observation that the flies fed with Amalaki Rasayana (0.5 per cent) showed an increase in life span, while at the same concentration of Rasa Sindoor did not have any effect. Larvae reared on Amalaki Rasayana also seemed to develop earlier than those having regular food. Flies fed on Rasayana could also tolerate starvation much better.

Another major finding was that the flies fed on the Ayurvedic formulations could tolerate heat. Adult flies, three days of age, were exposed to heat, that would usually knock them off into a motionless state. Flies in each vial were watched and those that were knocked off were counted. Flies fed with either of the Ayurvedic formulations were found to tolerate heat quite well even when the duration of heat was extended.

Interestingly, feeding on Amalaki Rasayana or Rasa Sindoor improved fecundity, but the stage at which the formulation was effective varied. While larval and adult feeding with the Rasayana increased fecundity, feeding only during adult stage had no effect. However, when Rasa Sindoor was given in the adult stage, it was found to be effective. In larval stage, the bhasma had no effect.

 It may be interesting that in Ayurveda practice, Rasa Sindoor is not recommended for growing children but is indicated, among other things, for genital disorders and rejuvenation in adult subjects.

The study was published in ‘PloS ONE’ on May 14.

While the findings of this experiment are too many to be discussed here, Morgan’s Drosophila sure is going to gain fame as a good model to test out different Ayurvedic formulations in the future.

(Do not forget to keep track of the Sci-Bug, every Saturday)