A group of Japanese researchers have discovered a major cause of cloning inefficiency. Biochemists at the University of Amsterdam (UvA) made an important contribution to the evidence presented by the Japanese researchers. The research results were published this week in the journal Science Express.
The research focused on the cloning of mammals by somatic cell nuclear transfer (SCNT), also called nuclear transfer. The interest in cloning is great. With so-called ‘therapeutic cloning', an experimental technique, stem cells can be produced which could contribute in the future to the treatment and cure of diseases for which there is no medicine at present. In this form of cloning patient-specific stem cells are created. These are then used to treat the patient's disease.
Inefficiency unraveledCloning is still a very inefficient process, with only about 3% of embryos surviving. In addition, the surviving embryos often display abnormalities. The Japanese research team has found a major cause of this inefficiency. It appears that a gene normally involved in activating or inactivating the female X chromosome, remains active in the cloned embryos when it should actually be inactive. If this gene is disabled, the cloning efficiency is improved tenfold.
Biochemists from the UvA's Swammerdam Institute for Life Sciences (SILS) made a significant contribution to research by helping the Japanese team with their evidence. The UvA scientists provided an antibody that recognises the aforementioned gene. This confirmed the accuracy of the mechanism outlined by the Japanese researchers.
Publication detailsK. Inoue, T. Kohda, M. Sugimoto, T. Sado, N. Ogonuki, S. Matoba, H. Shiura, R. Ikeda, K. Mochida, T. Fuji, K. Sawai, A.P. Otte, X.C. Tian, X. Yang, F. Ishino, K. Abe and A. Ogura: ‘Impeding Xist expression from the active X chromosome improves mouse somatic cell nuclear transfer'. In: Science Express, 16 september 2010.