How did electrical pulses help create Dolly?

In the creation of Dolly the sheep, Ian Wilmut and his team at the Roslin Institute utilized electrical pulses to facilitate the fusion of a donor mammary gland cell with an enucleated, unfertilized egg cell.1

By applying these electrical pulses, the researchers successfully fused the two cells, which resulted in the transfer of the mammary cell's nucleus into the host egg cell. This process was a critical step in somatic cell nuclear transfer (SCNT), as it allowed the donor nucleus to be accepted and become functional within the egg's cytoplasm. Once fused, the reconstructed egg began to divide, eventually forming an embryo that was transferred to a surrogate mother.12