Question

The human insulin gene contains a number of sequences that are removed in the processing of the mRNA transcript. In spite of the fact that bacterial cells cannot excise these sequences from mRNA transcripts, explain how a gene like this can be cloned into a bacterial cell and produce insulin.

Answer 1

In order to produce human insulin in a bacterium you need to isolate the mature mRNA (after the excision of the introns), produce a DNA copy using the enzyme retrotranscriptase, clone the gene in an expression vector and transform bacterial cells with this genetic construct to produce the insulin.

Step-by-step explanation:

Eukaryotic cells perform a process called splicing, in which introns (the non-coding fragments of the gene). are excised from the mRNA Prokaryotic cells (i.e. bacteria) don’t perform this process. So, in order to produce a recombinant protein in a bacterium, insulin in this case, the best strategy should be to produce a complementary DNA (cDNA) of the mature mRNA (AFTER the splicing process, the excising of the introns).