| abstract |
DNA transfer vectors which contain in their nucleotide sequence a subsequence which has the structure of the gene of a higher organism and which has been produced by a transcription on a gene of the higher organism are described. For example, this gene can encode the A chain or the B chain of human insulin or else be a gene which encodes the growth hormone of a higher organism. The DNA transfer vector is prepared by isolating from cells an mRNA which encodes the desired protein, specifically essentially free of proteins, DNA and other RNA. Then a double-stranded cDNA is synthesised, in which one strand has a nucleotide sequence which is complementary to that of the mRNA, in this way a cDNA is obtained which has a nucleotide sequence which encodes the desired protein. A DNA transfer vector with reactive ends is linked to the double-stranded cDNA, resulting in the desired DNA transfer vector. The DNA transfer vectors can be used to modify microorganisms which then contain a nucleotide sequence having the structure of a gene of a higher organism. |