Introduction To Genetics - Genetic Engineering

Genetic Engineering

Since traits come from the genes in a cell, putting a new piece of DNA into a cell can produce a new trait. This is how genetic engineering works. For example, rice can be given genes from a maize and a soil bacteria so the rice produces beta-carotene, which the body converts to Vitamin A. This can help children suffering from Vitamin A deficiency. Other genes that can be put into crops include a natural insecticide from the bacteria Bacillus thuringiensis. The insecticide kills insects that eat the plants, but is harmless to people. In these plants, the new genes are put into the plant before it is grown, so the genes are in every part of the plant, including its seeds. The plant's offspring inherit the new genes, which has led to concern about the spread of new traits into wild plants.

The kind of technology used in genetic engineering is also being developed to treat people with genetic disorders in an experimental medical technique called gene therapy. However, here the new gene is put in after the person has grown up and become ill, so any new gene is not inherited by their children. Gene therapy works by trying to replace the allele that causes the disease with an allele that works properly.