Human insulin is being commercially produced from a transgenic species of:

Explanation

Insulin is now being commercially produced by genetic engineering. Insulin consists of two short polypeptide chains: chain A and chain B, that are linked together by disulphide bonds. Insulin in mammals is synthesized as a prohormone which contains an extra stretch called the C-­peptide. During maturation, this C­-peptide is removed. The production of insulin could only have been commercially possible if somehow the maturation process of C­-peptide could've been skipped.This problem was solved in 1988 by Eli Lilly, an American company that prepared functional insulin from two DNA sequences corresponding to A and B chains of human insulin and introduced them in plasmids of E.coli to produce insulin chains. In this way, chains A and B were produced separately, extracted and combined by creating disulfide bonds to get human insulin.