History of Biology

• The task is to list at least 5 products of Genetic Engineering in various fields and to explain why and how a product was engineered, along with its pros and cons.

Introduction to Genetic Engineering

• Genetic engineering, also known as recombinant DNA technology or biotechnology, was coined in 1919 by Karl Ereky.
• Artificial selection has been used to manipulate organisms for thousands of years, exemplified by the domestication of horses, camels, and oxen as early as 8000 and 1000 B.C.
• In 6000 B.C., yeast was used to make beer.
• In 5000 B.C., plants like maize, wheat, and rice were bred.
• In 420 B.C., Socrates speculated on inheritance.
• In 400 B.C., Hippocrates proposed that males contribute to a child's character through semen, establishing the idea of heredity.
• Between 100-300 A.D., Hindu philosophers considered reproduction and inheritance, and the foundations of genetics began.
• Biochemical studies in the 19th century, particularly on nucleic acids, amino acids, and fermentation, redirected biology.
• In 1864-1865, Mendel presented his work on peas, but it was largely neglected, and the terms "gene" or "genetics" were not yet coined.
• In 1882 the first biotechnology products including the use of agar described by the Koch lab were founded.
• The development of the autoclave occurred in 1884 by a French company (Chamberland's Autoclaves).
• X-rays were discovered by W. Roentgen in 1895.
• X-ray crystallography was applied in 1913 by Sir William Henry Bragg and his son William Lawrence Bragg, among others.
• In 1945, William Astbury coined the term "molecular biology."
• In the early 1950s, Rosalind Franklin and Maurice Wilkins obtained X-ray diffraction data for DNA proving essential for Watson and Crick's model.
• In 1951, Hershey demonstrated that DNA is the hereditary material and that bacteriophages mutated.
• Werner Arber identified restriction enzymes in the late 1960s.
• In 1970, Temin and Baltimore identified reverse transcriptase, leading to recombinant DNA technology.
• In 1971, Paul Berg spliced and recombined genetic material.
• The first recombinant DNA was produced in Boyer Laboratory in 1972.
• Genentech, the first biotechnology company, was established in 1976.
• The 1980s experienced a biotech boom.
• In 1983, Karen Mullis invented the polymerase chain reaction (PCR).
• In 1982, Genentech's recombinant interferon gamma and Eli Lilly's recombinant human insulin were marketed.
• In 1986 the Human Genome Project was launched.
• In the 1990s, GenPharm International created the first transgenic dairy cow to produce human milk proteins, authorized gene therapy.
• Flash news from Roslin Institute in 1997 announced the birth of Dolly the sheep.

Recombinant DNA Technology

• Recombinant DNA technology involves using enzymes and lab techniques to manipulate and isolate DNA segments to combine or splice DNA from different species to create genes with new functions.
• Encyclopedia Britannica defines this as the joining of DNA molecules from different organisms and inserting it into a host organism for new genetic combinations.
• A biotechnology approach with multidisciplinary applications that deals with important aspects of life, from health issues to food resources (Eberle C. 2022).
• Recombinant DNA is made from combining DNA from different sources through bacterial plasmids that are defined as autonomously replicating material.
• Stanley Cohen, Herbert Boyer, and their colleagues developed recombinant DNA technology between 1972 and 1974 at Stanford University and the University of California, San Francisco.
• Bacteria contain plasmids, extra loops of DNA, in addition to their chromosome, discovered in 1959.
• Investigators had isolated several plasmids including restriction endonucleases by the early 1970s.
• Herbert Boyer and Stanley Cohen combined restriction endonuclease and plasmid expertise in 1972.
• A year later, the team inserted a gene from a frog into bacteria.

Tools of Recombinant DNA Technology

• Plasmids are physically separate from chromosomal DNA and replicate independently.
• Plasmids typically have a number of genes notably, antibiotic resistance, can be passed from one cell to another.
• Recombinant DNA methods are used to splice genes into a plasmid.
• Restriction enzymes are molecular scissors that cut DNA sequences at specific sites for gene manipulation.
• Restriction enzymes used for rDNA technology recognize short sequences in DNA and cleave the DNA at that site to produce cohesive (sticky) or blunt-ended fragments.
• DNA ligase attaches 2 pieces of DNA together

Process of Recombinant DNA Technology

• The process requires a sequence of steps. They include:
• Isolation of genetic material to isolate the desired DNA in its pure form.
• Cutting the gene through restriction enzymes.
• Amplifying gene through Polymerase chain reaction (PCR).
• Ligation of DNA Molecules through a cut fragment of DNA and the vector and DNA ligase.
• Insertion of Recombinant DNA Into Host.
• The process is termed Transformation and gets multiplied and is expressed in the form of the manufactured protein

Insertion of Recombinant DNA

• Transformation is a process of Recombinant DNA that transfers genes

Vectorless Gene Transfer

• Uses vectorless gene transfer in two methods:
• Electroporation is an non-viral delivery system that allows genetic material (DNA and RNA), proteins, drugs or other molecules to enter cells.
• Protoplast fusion produces a hybrid protoplast.
• Also the Microinjection method is a transformation method when inserting DNA into giant cells to produces transgenic mice.

Transduction

• Transduction is the process where genetically engineered bacteriophages-viruses that parasitize bacteria are introduced into the cell to create a recombinant DNA.

Applications of Recombinant DNA Technology

• In the Industry cyanobacteria and E. coli bacteria have been modified to produce plastic (polyethylene), fuel (butanol), and diesel fuel.
• Gene Therapy is a treatment of genetic diseases, removal and replacement of defective genes with normal healthy functional genes.
• It can treat Sickle cell anemia and Severe Combined Immuno-Deficiency as applications in the health and medicine fields.
• The use of insulin, vaccines production, production of medically and medications are some medically production and pharmaceuticals.
• In the environment, it is used for alternative fuel and bioremediation.
• In agriculture recombinant DNA can make insect resistant crops, herbicide resistant crops drought crops etc.

Products of Genetic Engineering

• Glow-in-the-dark cats are genetically engineered by inserting DNA from jellyfish using a virus.
• This causes the cat to produce a fluorescent protein in its fur.
• Fast-Growing Salmon are engineered using genes from two other fish.
• Salmon continually produce growth hormones.
• GM salmon reach a length of 24 inches and a weight of 6.6lbs after 18 months.
• By comparison farm salmon reach a length of 13 inches and a weight of 2.8lbs after 18 months.
• Grapes are genetically engineered to be seedless.

Test your knowledge of key milestones and individuals in biology's history. Questions cover genetics, molecular biology, microbiology, key experiments, and historical observations.