Genetic Engineering

Genetic modification occurs naturally via mutations, leading to new species.
Human intervention today utilizes biotechnology processes for genetic alteration.
Genetic Engineering: Direct manipulation of an organism's genes.
Biotechnology: Scientific procedures applied to optimize living organisms for human benefit or environmental improvements.
Genes can be:
- Turned off or on
- Deleted or deactivated
- Foreign genes inserted into chromosomes.

Introduces new, beneficial genes into organisms, creating genetically modified organisms (GMOs).
Recombinant DNA: DNA formed by combining DNA sequences that do not normally occur together.
Technology involved in moving desired genes into cells via a vector.
Vector: Can be a virus (bacteriophage) or plasmid that transfers genetic material.
Plasmid: Circular, double-stranded DNA molecule found in bacteria, separate from the chromosomal DNA.

The newly formed organism's functionality follows the instructions of the inserted gene.
Proteins synthesized according to the new gene codes.
Bacteria are cultured to produce many working copies (clones) for large protein yield.
Examples of proteins from recombinant DNA:
- Human growth hormone (for dwarfism)
- Interferon (for hepatitis B and C, cancer, multiple sclerosis)
- Factor VIII (for hemophilia B).

Bacteria are used as vectors to produce insulin:
1. Gene Isolation: Gene coding for insulin is extracted from human pancreas.
2. Restriction Enzymes: Cut DNA strands at specific sites to isolate insulin gene.
3. Plasmid Removal: E. coli plasmid is also cut open using restriction enzymes, creating sticky ends.
4. Joining: Enzyme ligase binds the insulin gene to the plasmid, forming recombinant DNA.
5. Re-insertion: Recombinant plasmid is inserted back into E. coli, creating a GMO that produces insulin.
6. Culturing: The bacteria grow in optimal conditions producing insulin in large quantities.
Advantages of insulin production: Rapid, inexpensive, few side effects; yeast can also be used as vectors.

An experimental technique replacing faulty genes or introducing new genes to cure diseases.
Example: Introducing a normal gene to correct a missing or defective protein due to mutation.
Gene Delivery: Uses vectors (usually viruses that are disabled to prevent disease in the patient).
Future applications include treating cancer, cystic fibrosis, heart diseases, hemophilia, and AIDS.
Continuing challenges include improving gene delivery methods, cell targeting, and gene control.

Direct Delivery: Vectors injected directly into tissues, taken up by cells.
Cell-Based Delivery: Patient cells are treated with vectors, then returned to the patient.

Artificial Selection: Farmers control plant reproduction for beneficial traits.
Selective Breeding: Result of artificial selection, leading to genetically modified organisms (GMOs).
Transgenic Organism: Develops from cells with recombinant DNA containing introduced genes (transgenes).

Genetic engineering is informed by indigenous practices, creating more productive crops through combined knowledge.
Importance of understanding both approaches for enhanced agricultural science.

Gene-Gun Method: Uses metal pellets coated with DNA fired into plant cells to produce GM crops.
Recombinant DNA Method: More controlled, utilizing the Ti plasmid from Agrobacterium tumefaciens to insert genes into plant cells.

Polyploidy plants have more than two homologous chromosome sets, such as broccoli and cauliflower.
In agriculture, polyploid plants lead to seedless varieties and larger yields.

Allows for disease resistance, increased pest tolerance, enhanced nutrient content, and improved environmental tolerance (e.g. drought, salinity).
Notable examples include disease-resistant rice and drought-resistant maize.

High costs associated with biotechnology and required skilled labor.
Potential ecological risks (e.g., harm to non-target wildlife and biodiversity threats).
Risks of interbreeding and unexpected gene spread to wild species, causing potential health issues and allergies.

Safety assessments done by genetic research bodies ensure the safety and efficacy of GM crops.
Regulations are handled at various levels, including international agreements concerning trade and biosafety.

NGOs monitor and publicize genetic engineering topics, promoting biodiversity and responsible use of GMOs.

Techniques such as embryonic nuclear transfer and somatic cell nuclear transfer (used for cloning Dolly).
Result in transgenic animals with desired genetic traits and conserve endangered species.

CRISPR-Cas9: A revolutionary gene-editing technique derived from bacterial immune systems.
Allows for precise genetic modifications, enabling significant advances in medicine and agriculture.

Ethical debates arise over potential applications in humans, including designer babies and long-term genetic effects.
Ongoing discussions on regulatory approaches to manage CRISPR's rapid advancements and societal implications.