A transfer techinque to clone buffalo

Researchers at the Roslin Institute in Edinburg produced Dolly, the world’s first adult cloned mammal, by transferring a cell from the udder of a superior breed sheep into an enucleated egg cell from another sheep. The resulting cell complex was then implanted into asurrogate sheep.

Similarly, scientists at the National Dairy Research Institute (NDRI) in Karnal removed the nucleus from the egg of a buffalo. In its place they put a cell from another embryo of elite parentage and grew the embryo up to a 32-cell stage, when it is ready for implantation into a surrogate buffalo.

Theoretically, each of the 64 cells of the donor embryo can be transferred into 64 enucleated egg cells to produce 64 embryos. In practice, however, 12 to 16 embryos are transferred with success, said M L Madan, who was part of the NDRI team and heads the Animal Sciences Division at the Indian Council of Agricultural Research (ICAR).

There has been no report to date on cloning embryos of buffalo though it has been tried on rabbits, mice, sheep, goats, cattle and pigs, Madan Puri and NDRI colleagues S K Singla and R S Manik reported in the journal.

The NDRI scientists made a cut in the jelly-like covering on a mature egg and pressed it from one side to squeeze out the nucleus. “The new approach gave 88.2 per cent of enucleated eggs for cloning,” they reported.

A donor buffalo embryo at the 64-cell stage was isolated and transferred to a culture medium. Individual cells from it were transferred gently into the enucleated eggs.

The study says speedy transfer of cells from the original embryo is critical in obtaining large number of identical copies. Short electric pulses help fusion of the two cells after transfer.

The NDRI scientists were able to grow the complex up to 38-cell stage under in-vitro conditions.