What organism was the first successfully cloned vertebrate using mature body cells?

The first successfully cloned vertebrate using mature body cells was a sheep named Dolly. This groundbreaking achievement, accomplished in 1996 by scientists at the Roslin Institute in Scotland, involved the process of somatic cell nuclear transfer (SCNT). In this method, the nucleus of a differentiated adult cell was transferred into an enucleated egg cell, which then developed into a fully formed organism, demonstrating that mature cells could be reprogrammed to develop into a new individual.

Dolly's successful cloning was significant because it challenged previous assumptions regarding cellular differentiation and the potential for cloning from adult cells. This event marked a pivotal moment in both genetics and biotechnology, leading to further research in cloning, stem cell studies, and discussions about the ethical implications of such technologies.

The other organisms listed, while notable in cloning research and genetics, were not the first to be cloned from mature body cells. For instance, mice have been cloned, but these events took place after Dolly's landmark achievement. Frogs have also been cloned, but they were primarily used in earlier cloning experiments that did not involve mature body cells. The cloning of dogs has occurred since Dolly, but it was not the first example in this field. The historical precedence set by Dolly is what makes her