Model organisms used in cloning

Answer 1

Typically, a specific DNA molecule is inserted into a vector DNA molecule that can carry foreign DNA, and the resulting recombinant DNA is introduced into a host organism (often the common bacterium Escherichia coli or the yeast Saccharomyces cerevisiae). Large numbers of genetically identical host organisms, each carrying the same specific foreign DNA molecule, can be produced, allowing the DNA or its protein product to be produced in large quantities.

Cloned DNA can also be incorporated into the genomes of multicellular organisms to create a transgenic organism.

Genetically modified organisms (GMOs)

One example of a GMO is the development of "golden rice," designed to reduce blindness caused by vitamin A deficiency in rice-consuming areas of the world. A polished rice grain, which is the portion of the seed that provides nourishment (the endosperm) does not contain beta-carotene, the substance the human body converts into vitamin A, yet many plants with yellow/orange colored leaves or flowers produce it in abundance. To convert rice endosperm into a beta-carotene-rich food, a transgene was constructed with the genes required for beta-carotene production and inserted into rice cells. The transgene consists of a cDNA for phytoene synthase, from a daffodil flower library, plus other sequences. Rice with these extra genes show a rich "golden" color from the beta-carotene that accumulates in the rice grain. If golden rice can be bred into commercial strains and enough can be provided into the diet to reduce the incidence of vitamin A-related blindness, current agitation against GMO crops may evolve into enthusiasm for their application.