Researchers in Kerala to use modern techniques for DNA analysis

Alison is not aware of her white cousin housed in a rescue centre at Puducherry. She, however, is on chattering terms with the grey striped version of her species scurrying about in a cage near hers in the laboratory of the Department of Zoology, University of Kerala, here.

Ever since she was captured from the outskirts of the city in 2008, the black squirrel, named after a United Kingdom-based scientist who helped identify the animal, has been the subject of intense scientific curiosity.

Following up on preliminary investigations that have confirmed the black and white animals to be variants of the Indian striped palm squirrel, researchers here have launched a mission to decipher the genetic causes of the colour change.

The multi-institutional project will use modern techniques for DNA analysis.

Efforts are focussed on identifying the chromosome responsible for the genetic mutation in the grey squirrel, and the resultant colour change.

“Apparently, one of the genes in the animal acted as a switch to activate the change in pigmentation,” explains Oommen V. Oommen, Council of Scientific and Industrial Research Emeritus Scientist, who heads the project.

While the research team has black and grey squirrels in its possession, the scientists have collected blood and hair samples of the white variant from Puducherry where the animal is kept in a rescue centre operated by the Forest Department.

Unlike the United Kingdom, the United States and Canada where the black squirrel has attained sizeable populations, there have been no reports of the mutant versions being sighted anywhere else in India.

“We had earlier carried out gene sequencing to establish that the black squirrel is a variant of Funambulus palmarum [Indian three-striped palm squirrel]. That work will have to be repeated to ascertain the mutation responsible for melanisation [black pigmentation],” says Dr. Oommen.

“Our attempt is to understand the basic science behind the colour change, what it is that throws the switch. The project could have far reaching implications for mankind. It would perhaps obviate the need to use bleaching creams for a fair skin or have a sunbath for a tan.”

The sequencing programmes are expected to generate meaningful data in the next two months.

The team includes Dr. Sanal George, Rajiv Gandhi Centre for Biotechnology; Dr. Dileep Kumar, Anaswara Krishnan and Dr. Achuth Sankar S. Nair; Department of Computational Biology and Bioinformatics; K. Ramachandran and A.S. Vijayasree, Department Of Zoology, University of Kerala; Dr. Divya, Central University, Kasaragode; Dr. Helen Mcrobie , East Anglia University, Cambridge; Dr. M.A. Akbarsha, Bharatidasan University; Dr. Anil Kumar, Deputy Conservator Of Forests, Puducherry; and Dr. Jacob Alexander, Veterinary surgeon, Thiruvananthapuram Zoo.

This is not the first time Dr. Oommen and his team have been on the trail of animals exhibiting abnormal colour characteristics. The scientists have already lined up their next project, to carry out gene sequencing of a hen that changes colour.

Belonging to a small-time farmer near here, the bird has acquired a celebrity status for its ability to change from black to white and back without shedding feathers. “Unlike the squirrel, the switch seems to be active throughout the life of the bird,” says Dr. Oommen.

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