Chapter 12: Biotechnology and Its Applications

Gene expression can be controlled with the help of RNA by a method known as RNA interference (i.e., RNAi) in which a gene is “knocked out’’ and the cellular mechanism is degraded. The specific mRNA gene is silenced by binding a complementary double-stranded RNA (i.e., dsRNA) to the mRNA, which inhibits the translation process. For example, the Agrobacterium vector forms a complementary dsRNA with the nematode genes and inhibits translation, and the nematode infection gene expression doesn’t occur.

India is one of the developed countries and very rich in biodiversity when compared to other developed countries. If countries like India don’t have the proper biological patenting rules for its traditional knowledge, then the developed countries would keep on exploiting its resources without giving any due credit or compensation.

1. Genetically modified plants are more resistant towards abiotic stresses like climate, temperature and pH changes.

2. Chemical pesticides are resisted, which enhances crop production.

3. Genetically modified plants are used to grow crops with higher nutritional values like starch, proteins, and vitamins.

Recombinant DNA vaccines are vaccines which are manufactured by Recombinant DNA technology. It involves the construction of a plasmid using a copy of DNA from a pathogen with an empty plasmid. Example: Hepatitis B and Japanese encephalitis vaccine.

The line of treatment for a genetic disease is different from infectious diseases as the genetic disease requires a change or alteration in the gene instead of any part or organ. Generally, the gene therapy method is required for the treatment of genetic diseases, which is carried out at the embryo stage. These are caused by pathogens.

A probe is used in molecular diagnostics for labelling a gene or small fragment of genome segment. For labelling DNA sequence, RNA or DNA fragment is used, and also for genome mapping and sequencing.

A probe is generally radio-labelled or fluorescent-labelled and detected by various methods.

The first patient who was given gene therapy was a four-year-old with adenosine deaminase (ADA) deficiency. The treatment is recurrent because these ADA cDNAs are not immortal. Thus it is required o be repeated for new cells and cure the adenosine deaminase (ADA) deficiency.

Upstream processing is the method and technique which are involved in the isolation of DNA. An example of upstream processing is used in the production of Insulin using rDNA technology. Downstream processing is the separation, purification, quality control and clinical trials of a product before commercially selling it. An example of downstream processing is the production of Insulin using rDNA technology.

Antigen- Any foreign body which can stimulate antibody formation by the immune system

Antibody- it is the glycoprotein produced by the immune system for defence purposes.

Two diagnostic tests based upon antigen-antibody relationship are-

a. ELISA for AIDS

b. Pregnancy test

Yes, ELISA can be used to detect the presence of phenylketonuria. The patient in which enzyme-antibody complex enzyme is absent will give a negative test and would prove the absence of the enzyme.