GENETIC ENGINEERING AND BIOTECHNOLOGY Regents Biology

OBJECTIVES Upon completion of this unit students will be able to: 1. Define the terms Genetic Engineering and Biotechnology. 2. Describe the methods used by plant and animal breeders to improve their crops and animals, including selective breeding, outbreeding and inbreeding. 3. Describe the cloning process. 4. Describe what recombinant DNA is. 5. State how the universality of the genetic code makes genetic engineering possible. 6. Explain the use of plasmids and restriction enzymes in the transferring of new genes into bacteria. 7. List some ways in which genetic engineering and biotechnology has been used to benefit people. 8. State the goal(s) of the Human Genome Project. KEY WORDS genetic engineering biotechnology recombinant DNA restriction enzymes cloning gene selective breeding inbreeding outbreeding plasmid gene therapy genome

I. INTRODUCTION Genetic engineering is the SCIENTIFIC ALTERATION OF THE STRUCTURE OF GENETIC MATERIAL IN A LIVING ORGANISM, more specifically, it is the technology of preparing recombinant DNA in vitro (artificial environment outside of the organism) by cutting up DNA molecules and splicing together fragments from more than one organism. Biotechnology is the APPLICATION OF THE PRINCIPLES OF ENGINEERING AND TECHNOLOGY TO THE LIFE SCIENCES and includes genetic engineering. It includes the use of microorganisms, such as bacteria or yeasts, or biological substances, such as enzymes, to perform specific industrial or manufacturing processes. Applications include the production of certain drugs, synthetic hormones, and bulk foodstuffs as well as the bioconversion of organic waste and the use of genetically altered bacteria in the cleanup of oil spills.

Timeline of Events – How did we get here? A LONG time ago, in 4000 B.C., Egyptian agriculturalists used selective breeding to increase the production of various crops. But we’ve come a long way since then… II. BREEDING By selecting the most productive plants or animals to produce the next generation, people have found that the productivity of a domesticated species can gradually increase. Here’s some ways that plants and animals are bred: 1. SELECTION – CHOOSING OF ANIMALS AND PLANTS WITH THE MOST DESIRABLE TRAITS FOR MATING (aka – SELECTIVE BREEDING)       2. INBREEDING - MATING OF GENTICALLY CLOSE INDIVIDUALS TO OBTAIN DESIRED RESULTS (BROTHER/SISTER, MOTHER/SON, FATHER/DAUGHTER, etc.) Increases the number of homozygous genes due to less genetic variation May bring out unwanted effects 3. OUTBREEDING – MATING OF INDIVIDUALS NOT CLOSELY RELATED Brings new beneficial alleles “Hybrid vigor” = hybrid offspring are superior to the parents (ex. mule)

III. CLONING CLONE = GROUP OF ORGANISMS WITH THE SAME GENES Technically, it is a type of ASEXUAL reproduction The purpose of cloning is to PRODUCE LARGE NUMBERS OF IDENTICAL ORGANISMS FOR RESEARCH Problems with cloning: SPONTANEOUS GENETIC CHANGES (MUTATIONS) IN CLONES ETHICAL ISSUES

Here’s how it’s done:

IV. GENE SPLICING Altered (changed) DNA is called RECOMBINANT DNA Main goals of genetic engineering: CORRECT GENETIC DEFECTS PRODUCE DESIRED PROPERTIES (PLANTS AND ANIMALS)

A. PLASMIDS Plasmids are SEGMENTS OF DNA IN THE SHAPE OF RINGS FOUND IN BACTERIA; SEPARATE FROM CHROMOSOMES Steps to Gene Splicing: Identify the location of the desired gene in the human DNA. (The Human Genome Project has made EXTENSIVE progress here!) CUT the DNA containing the desired gene to be spliced into small pieces using RESTRICTION ENZYMES INSERT the gene into a small ring of bacterial DNA called a PLASMID found in Escherichia coli (E. coli). REPLICATE the organism (bacteria) containing the desired gene. Now we have our RECOMBINANT DNA!

An illustration of how this is done to human DNA using restriction enzymes:

Dangers of genetic engineering: 1. POSSIBLE NEW DISEASES 2.  UNCONTROLLABLE SPREADING 3.  ETHICAL ISSUES  

THE HUMAN GENOME PROJECT (HGP) The goal of the HGP is to SEQUENCE AND MAP ALL OF THE GENES OF THE HUMAN (ALL OF THE GENES ARE KNOWN AS THE HUMAN GENOME) The HGP was Set up in 1989 and finished sequencing the human genome in 2003, two years ahead of schedule! Let’s discuss some pros and cons of the HGP:   PROS CONS DIAGNOSIS AND PREDICTION OF DISEASES (For example, breast cancer was found to be linked to chromosome 17) INSIGHTS INTO BASIC BIOLOGY DEVELOPMENT OF NEW DRUG THERAPIES AND TECHNOLOGIES GENETIC DISCRIMINATION WHOSE DNA IS IT ANYWAY? REPRODUCTIVE DECISION MAKING