Introduction to Genetic Engineering

Study Notes

Genetic Engineering Definition

Genetically engineered organisms have had their DNA altered by humans
Genetic engineering is the process of altering an organism’s DNA
Ethical considerations surround genetic engineering as humans are altering the fundamental building blocks of life
Practical applications exist for genetic engineering across medicine, agriculture, and commercial markets

Genetic Engineering History

Selective breeding, dating back thousands of years, is an early form of genetic engineering
Modern genetic engineering started in 1973 with scientists Herbert Boyer and Stanley Cohen, who first successfully cut and pasted DNA into bacteria
The Supreme Court ruling allowing patenting of genetically engineered organisms in 1982 facilitated further research and applications

Genetic Engineering Process

Genetic engineering involves processes of isolating, cloning, and inserting genes into a host organism’s genome
Host: The organism receiving the modified DNA
Vector: The method used to transfer recombinant DNA into a host, which can be made of DNA or composed of a living system (e.g., bacteria or virus)
Plasmid: A circular piece of DNA used as a vector to transfer small pieces of recombinant DNA into bacteria
Restriction enzymes: Cut both the isolated gene and the vector at specific sequences, creating complementary ‘sticky ends’
DNA ligase: An enzyme that joins the isolated gene and vector together, creating a recombinant DNA molecule

Transgenic Organisms vs. Genetically Modified Organisms

Transgenic organisms: Have DNA from a different species incorporated into their genome
Genetically modified organism (GMOs): Organisms with altered DNA, but not necessarily containing DNA from a different species
All transgenic organisms are GMOs, but not all GMOs are transgenic

Genetic Engineering Examples

Agriculture

Bt cotton:
- Contains genes from Bacillus thuringiensis bacteria
- These genes produce an insecticide that helps protect the cotton from insects, leading to increased crop yield
Golden rice:
- Contains genes for plant phytoene synthase (psy) and a bacterial phytoene desaturase
- These genes produce beta-carotene, a key precursor to vitamin A, in the rice grains
- Aims to address vitamin A deficiencies, particularly in developing nations

Medicine

Human insulin production in bacteria:
- Bacteria are genetically engineered with the human gene for insulin, enabling mass production of the hormone
- Enables treatment of diabetes

Research

Knock-in and knock-out organisms:
- Used to study gene function by adding or removing genes from the genome
- Help understand the effects of specific genes and their roles in development and disease
Disease models:
- Created to understand human disease by modifying genes in cells or organisms
- Allow scientists to study disease progression, investigate potential treatments, and identify drug targets

Commercial Uses

Glow organisms:
- Organisms engineered to express the green fluorescent protein (GFP) from jellyfish
- Used for research and commercial purposes
- Examples include rabbits, cats, and fish

Description

Explore the fundamentals of genetic engineering, including its definition, history, and processes. Understand how DNA alteration has practical applications and ethical implications in various fields such as medicine and agriculture.