Quick questions on Biotechnology applications in agriculture, medicine and industry: HSC Biology Module 6

Bt cotton (transgenic insect resistance). The cry1Ac gene from Bacillus thuringiensis is inserted into cotton, where it expresses a Cry protein lethal to bollworm larvae. Reduces pesticide spraying, increases yield, and now accounts for the majority of cotton grown in India, China, the United States and Australia.

Recombinant human insulin (Humulin, 1982). The first commercial recombinant drug. Human insulin gene is inserted into E. coli using a plasmid vector; bacteria express and secrete insulin, which is purified for clinical use. Replaced porcine and bovine insulin and removed allergic complications.

Recombinant chymosin (rennet). Calf rennet historically extracted from slaughtered calves' stomachs is now produced in genetically modified Aspergillus or yeast, supplying the cheese industry without animal slaughter and at lower cost.

DNA profiling. Short tandem repeat (STR) analysis identifies individuals from a blood, saliva or tissue sample. Used in criminal forensics, paternity testing and identification of disaster victims.

Benefits. Higher yields, fewer pesticides, cheaper medicines, replacement of animal-derived products, treatments for previously untreatable diseases.

The cry1Ac gene from Bacillus thuringiensis is inserted into cotton, where it expresses a Cry protein lethal to bollworm larvae. Reduces pesticide spraying, increases yield, and now accounts for the majority of cotton grown in India, China, the United States and Australia.

Rice engineered to express beta-carotene (vitamin A precursor) using genes from maize and a soil bacterium. Aims to reduce vitamin A deficiency in populations dependent on rice. Approved in the Philippines in 2021.

Soybean, canola and corn engineered with bacterial EPSPS gene confer resistance to glyphosate, allowing farmers to spray over a growing crop. Increases yields and reduces tillage, but selects for glyphosate-resistant weeds and concentrates farm income towards seed and chemical companies.

The first commercial recombinant drug. Human insulin gene is inserted into E. coli using a plasmid vector; bacteria express and secrete insulin, which is purified for clinical use.

Hepatitis B and HPV vaccines use yeast-expressed viral surface proteins rather than live or attenuated virus, removing infection risk during manufacture.

Inserting a functional copy of a gene into a patient's cells to correct a genetic disease. Examples: Luxturna (RPE65 for inherited blindness, approved 2017), Zolgensma (SMN1 for spinal muscular atrophy, approved 2019).

Engineered antibodies (e.g. trastuzumab for HER2-positive breast cancer) target specific cell-surface markers with minimal off-target effects.

Calf rennet historically extracted from slaughtered calves' stomachs is now produced in genetically modified Aspergillus or yeast, supplying the cheese industry without animal slaughter and at lower cost.

Engineered microbes ferment plant biomass into ethanol or biodiesel as renewable transport fuel.

Bacteria such as Pseudomonas putida engineered to metabolise oil hydrocarbons or heavy metals at contaminated sites.