A low percentage of success in cloning mammals can be explained by the fact that in the natural conditions, not only half of the DNA set enters the egg from the spermatozoon, but several other important molecules for the development of the embryo.

At least, according to scientists from the joint American-British group, who published an article on the pages of the journal Nature. "The role of men in development (embryo) at an early stage is more significant than previously thought," said one of the authors of the study, Stephen Krawetz of Wayne State University in Detroit. Scientists have identified six signal RNA molecules, which, apparently, are transmitted to the egg at the time of fertilization.

The scientists noted that these RNAs are determined in the fertilized egg and in the sperm, but are not detected in the unfertilized ovum.

"We were able to demonstrate that, along with the DNA component, a human RNA component. This was proved for the first time, "Stephen Kravets said in an interview.

The authors of the discovery believe that paternal RNA plays an important role for the embryo, activating the correct program of its development in the early stages. This can explain the failure of many cloning attempts, because in this case RNA does not receive medicus into the egg. En.

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