Telling them apart

The Western Ghats,known for their extraordinary biological richness,are home to about 350 species of butterflies,some of...

The Western Ghats,known for their extraordinary biological richness,are home to about 350 species of butterflies,some of which look so similar to one anotheras in the case of the butterfly family Lycaenidaethat they cannot be distinguished without the help of experts. The only sure way to tell one from another is by examining the mitochondrial DNA of each butterfly and determining its species based on differences in genetic make-up.

Two Pune-based scientists,Yogesh S Shouche and H.V. Ghate,have generated distinct DNA barcode sequences of 100 morphologically identified species of butterflies from five different families as part of a projectfunded by the Department of Biotechnology,Government of Indiastarted in 2007. The DNA library generated at the National Centre for Cell Sciences NCCS will help people identify butterflies from the Western Ghats.

Shouche says,With the kind of biodiversity India has,cataloguing organisms for their conservation becomes important. DNA barcoding will help popularise taxonomy and attract young people to study biodiversity in a systematic way.

DNA barcoding has,in the past,thrown up surprising discoveries. Five years ago,barcoding of museum specimens of butterflies of the family Lepidoptera showed that the skipper butterfly Astraptes fulgerator,found in Costa Rica,was actually a complex of 10 local species.

Some of the butterflies found in the Western Ghats are too small to be identified based on their wing colour pattern. Factors like seasonal variation are major obstacles in butterfly identification. DNA barcoding is aimed at overcoming such problems, Shouche adds.

Ghate says labs around the world are barcoding known species and the generated database will help in identification of species in the future. Whether the DNA sequence comes from a piece of tissue from the egg,larva,pupa or adult,it doesnt matter, he says.

The biggest challenge is collecting samples. And Ghate thinks a collective and collaborative effort from scientists from all over the country can make it easier. Shouche says getting good quality DNA from samples is difficult,especially when one is working with preserved specimens.

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NCCS scientists are already in the process of building a DNA barcode library of birds in collaboration with the Indian Air Force to help study birdstrikes on airplanes. Once these birds are identified,precautions can be taken to manage bird populations in and around airfields and prevent accidents. Along with this project,we have also started work on DNA barcoding of moths,fish and dragonflies, Shouche says. The butterfly barcoding project will be complete by the end of the year.