Applications of DNA technology

Bio3B

Biotechnological techniquesBiotechnological techniques are being developed and used for• identification of species and hereditary diseases by

o DNA sequencing o profiling techniques o PCR (polymerase chain reaction)o genetic probes

• production of proteins, hormones and vaccines by DNA recombinant techniques (including restriction and ligase enzymes) e.g. to produce insulin, auxins

• production of new varieties or breeds of plants and animals eg GMO organisms with pest resistance or drought tolerance

• Cloning or tissue culture of endangered species or to increase numbers of organisms with a desired trait

Applications of biotechnology

Applications of DNA technology

Agriculture

• Pest or disease resistant crops

• Improved productivity or nutritional quality in crops or animals

• Cloning of plants or animals with superior qualities

Pest resistant crops – Bt cropsBacillus thuringiensis, commonly known as

Bt, is a bacterium that occurs naturally in the soil.

For years, bacteriologists have known that some strains of Bt produce proteins that kill certain insects with alkaline digestive tracts.

When these insects ingest the protein produced by Bt, the function of their digestive systems is disrupted, producing slow growth and, ultimately, death.

Bt is very selective — different strains of the bacterium kill different insects and only those insects.

Strains of Bt are effective against European corn borers and cotton bollworms (Lepidoptera), Colorado potato beetles (Coleoptera), and certain flies and mosquitoes (Diptera).

Bt is not harmful to humans, other mammals, birds, fish or beneficial insects.

GM animals

Many different types of animals have been genetically modified - for food production or research.

Even though many types of animals are used, mice, however, make up 98 percent of GM animals.

Although scientists use fewer animals in research, GM animals make up about 21 percent.

GM sheep with milk containing the human protein

AAT.

Genetically engineered bare skinned chickens – fast growing, low fat, less waste & less need for ventilation

Giant cow, three times the size of ordinary cattle, reared without fat to produce gallons of milk.

A genetically modified mouse (bottom) develops diabetes, but a mouse missing the Stat-4 gene (top) is protected from the disease.

Plant cloning

Also known as tissue culture

Allows rapid duplication of desirable plant

Used in commercial flower production and horticulture

Grafting allows cloning of desired plant by placing plant tissue on to the root stock of another plant eg grapes, roses

Cloning animals

The cloning of animals has many important commercial implications. It allows an individual animal with desirable features, such as a cow that produces

a lot of milk, to be duplicated several times. Mice have successfully been cloned from frozen tissue

Cloned mice provide identical test subjects for research

Environmental conservation• Seed banks• Species identification – research and

conviction of poachers• Biodiversity identification• Cloning of rare, endangered species

Species identification

Use of DNA sequencing to ‘bar code’ species DNA

Cloning and endangered or extinct species

Pyrenean ibex (extinct) and Gaur (endangered) have both been cloned, although the animals died shortly after birth.

Mice have been successfully cloned from frozen tissue and dead animals

Pyrenean ibex

Applications 1

How has DNA technology been used with these?

• Custom service beagles

• Wollemi pine

• Racing industry

• Cotton farming

• Wheat varieties

• Tasmanian Devil

• Painted dogs

Applications 1How has DNA technology been used with

these?

Cloning:

• Custom service beagles

• Wollemi pine

• Racing industry

Genetic engineering and breeding

• Cotton farming

• Wheat varieties

Captive breeding and DNA sequencing

• Tasmanian Devil

• Painted dogs

Applications 2How could it help with?• Tasmanian tiger - extinct• Koalas – endangered – habitat loss &

disease (Chlamydia)• Tuart trees – endangered – habitat

loss

Applications 2How could it help with?• Tasmanian tiger - extinct• Koalas – endangered – habitat loss &

disease• Tuart trees – endangered – habitat

loss

Adelaide University researchers are examining the DNA of animal droppings to try to work out if the Tasmanian tiger survived beyond its reported extinction in the 1930s.Some suggestion of cloning from skins or preserved embryos

Seed banks

Captive breeding programsKeeping and breeding Chlamydia free groups