NDDB scientists crack buffalo genome code

In what may improve India's milk production in the future, geneticists at the National Dairy Development Board (NDDB) in collaboration with US researchers have come out with a sophisticated tool to improve the water buffalo breed through genetic selection.

The scientists have successfully completed the “de novo genome assembly” of buffaloes that produces nearly 50% of India's milk yield.

“This will help identify the right type of bull (for breeding) through genetic selection,” said NDDB scientist Sudhakar Anathasayanam, one of the leaders of the team comprising scholars from NDDB and Johns Hopkins University. A Murrah buffalo was chosen for the study.

So what exactly is a “de novo genome assembly” and how it is different from sequencing the genome of a plant or animal?

Sequencing means mapping of an organism's complete genome. But in a genome assembly, a combination of short and long strands of the genome are sequenced separately to cover the maximum amount of genome mapped quickly.

A de novo assembly means doing the job from the scratch, without any reference point.

Once the fragmented genomes are mapped, they are put together to get a realistic sense of the complete genome. But the main challenge is to find out the right way of stitching the DNA strands together, explained a senior geneticist who is not associated with the work.

The NDDB team used a method called trio-binning for the task. “Our genome assembly has achieved more than 99% coverage. Its sufficient for genetic improvement of the animal through artificial insemination,” Anathasayanam told DH.

India has an estimated 113.3 million buffaloes, accounting for nearly 50% of the world buffalo population. They contribute more than 50% of India’s milk yield and the milk they produce has a higher fat percentage compared to cow milk.

Since buffaloes are widely reared in the developing countries for milk production, creating a reference genome will help improve the breed faster.

“The newly developed genome assembly would provide more insights about buffalo genome and desired impetus for implementing genomic selection programme in buffaloes to achieve faster genetic progress in Indian buffalo population,” said NDDB chairman Dilip Rath.

Sudhakar said his team would continue the work to finish the annotation (of the genome) so specific attributes of the buffaloes genome are identified.