Biotechnology and its Applications Test - 9

In 1997, the first transgenic cow, Rosie, produced human protein-enriched milk at 2.4 grams per litre. This transgenic milk is a more nutritionally balanced product than natural bovine milk and could be given to babies or the elderly with special nutritional or digestive needs.Rosie’s milk contains the human gene alpha-lactalbumin.

Transgenic animals are animals (most commonly mice) that have had a foreign gene deliberately inserted into their genome. Such animals are most commonly created by the micro-injection of DNA into the pronuclei of a fertilised egg which is subsequently implanted into the oviduct of a pseudopregnant surrogate mother. Transgenic cow, rat, rabbits and fish have been produced.

Dolly (5 July 1996 – 14 February 2003) was a female domestic sheep, and the first mammal cloned from an adult somatic cell, using the process of nuclear transfer.

Dolly had three mothers (one provided the egg, another the DNA and a third carried the cloned embryo to term). She was created using the technique of somatic cell nuclear transfer, where the cell nucleus from an adult cell is transferred into an unfertilized oocyte (developing egg cell) that has had its cell nucleus removed.

The hybrid cell is then stimulated to divide by an electric shock, and when it develops into a blastocyst it is implanted in a surrogate mother. Dolly was the first clone produced from a cell taken from an adult mammal.

Transgenic organisms produce useful biological products. Augmentation therapy is the use of alpha-1 antitrypsin protein (AAT) from the blood plasma of healthy human donors to augment (increase) the alpha-1 levels circulating in the blood and lungs of Alphas diagnosed with emphysema.

Human protein α-1-antitrypsin is used to treat emphysema is also obtained from transgenic animal.

Transgenic mice are being developed for use in testing the safety of vaccines before they are used on humans. Transgenic mice are being used to test the safety of the polio vaccine. If successful and found to be reliable, they could replace the use of monkeys to test the safety of batches of the vaccine.

The cells of embryo are totipotent that means that they have ability to produce whole new organism form single cell. Dolly sheep was produced due to property of totipotency.

The batches of vaccine are tested for safety before use on human beings. Earlier vaccine batches are tested on monkey but now transgenic mice are used to test the safety of vaccine.

The first transgenic cow Rosie produced human protein enriched milk. The milk contained Alpha lactalbumin which was nutrionally more balanced than normal cow milk for babies.

Transgenic animals are developed to study normal physiology and development, vaccine testing, chemical safety testing, obtaining biological product etc. These animals are not used to study viral disease.

Transgenic animals are made to carry gene that make them sensitive to toxic substance than non-transgenic animals and exposed to toxic substance. Toxicity testing in transgenic animals allows us to obtain results in less time.