To produce Dolly, scientists used an udder cell from a six-year-old Finn Dorset white sheep. ... Then they injected the cell into an unfertilised egg cell which had its nucleus removed, and made the cells fuse by using electrical pulses. The unfertilised egg cell came from a Scottish Blackface ewe.

Reproduction in Animals: Finn Dorset Sheep and Dolly

Reproduction in animals can occur through sexual or asexual means. Sexual reproduction involves the fusion of male and female gametes, while asexual reproduction does not involve fertilization and the offspring are genetically identical to the parent.

Asexual Reproduction in Finn Dorset Sheep
Finn Dorset sheep are typically known for reproducing sexually. However, in 1996, a significant breakthrough occurred when Dolly, the first cloned mammal, was born at the Roslin Institute in Scotland. Dolly was a Finn Dorset sheep and her birth marked a major advancement in the field of reproductive biology.

The Process of Cloning Dolly
The cloning of Dolly involved a technique called somatic cell nuclear transfer (SCNT). Here is a detailed explanation of the process:

1. Isolation of the donor cell: A cell was taken from the udder of a Finn Dorset sheep, which served as the donor cell for cloning.

2. Removal of the nucleus: The nucleus of the donor cell was extracted using a fine glass needle.

3. Enucleation of the egg cell: An egg cell was obtained from another sheep and its nucleus was removed, leaving behind an empty egg cell.

4. Fusion of cells: The nucleus from the donor cell was inserted into the enucleated egg cell using a small electric shock. This resulted in the fusion of the two cells.

5. Creation of an embryo: The fused cell started to divide and develop into an embryo.

6. Implantation into a surrogate: The developing embryo was implanted into the uterus of a surrogate mother, who carried the pregnancy to term.

7. Birth of Dolly: Dolly was born after a normal gestation period and was genetically identical to the Finn Dorset sheep from which the donor cell was obtained.

Significance of Dolly's Birth
The birth of Dolly opened up new possibilities in the field of reproductive biology. It demonstrated that it was possible to clone mammals by transferring the nucleus of a specialized cell into an enucleated egg cell. This breakthrough raised ethical and scientific questions, and also offered potential applications in agriculture, medicine, and conservation.

Conclusion
Dolly, the first cloned mammal, was born through the process of somatic cell nuclear transfer. This involved the fusion of a donor cell nucleus with an enucleated egg cell, resulting in the development of an embryo. Dolly's birth marked a significant advancement in the understanding and manipulation of reproductive processes in animals.