Patent ID: 7799969

Claim:
Method for producing a cloned rat, said rat being genetically manipulated, comprising the following steps: a) removing a recipient rat ovocyte and maintaining the recipient ovocyte in vitro in a maintenance medium, wherein the recipient rat ovocyte is maintained at the metaphase stage of the second meiotic division in a maintenance medium including a reversible proteasome inhibitor sufficient to prevent activation of the ovocyte; b) transferring the nucleus of a rat donor cell nucleus into the recipient rat ovocyte of step a) wherein the donor cells have been genetically modified; c) removing the recipient rat ovocyte nucleus before or after the introduction of said donor cell nucleus to obtain a reconstituted rat ovocyte; and d) activating the reconstituted rat ovocyte by placing the reconstituted ovocyte in an activation medium containing an inducer of activation to obtain a reconstituted rat embryo; e) transferring the reconstituted embryo into the oviduct or uterus of a recipient female rat and said transferred embryo is allowed to become implanted and to develop into a cloned rat in the uterus of said recipient female, f) recovering a neonate at birth.