Recombinent DNA technology & Genetic engineering

Recombinant   DNA   Technology

Recombinant DNA technology - the technology of preparing recombinant DNA in vitro by cutting up DNA molecules and splicing together fragments from more than one organism. Recombinant DNA technology has significantly augmented the conventional crop improvement.

Creating Recombinant DNA:

Molecular cloning is the laboratory process used to create recombinant DNA

Fig:Process of Recombinant DNA Technology

In standard cloning protocols, the cloning of any DNA fragment essentially involves seven steps:
 (1) Choice of host organism and cloning vector,
 (2) Preparation of vector DNA, 
(3) Preparation of DNA to be cloned, 
(4) Creation of recombinant DNA, 
(5) Introduction of recombinant DNA into the host organism, 
(6) Selection of organisms containing recombinant DNA, 
(7) Screening for clones with desired DNA inserts and biological properties. 


Importance  of rDNA

• Better Crops (drought & heat resistance)
• Recombinant Vaccines (i.e. Hepatitis B)
• Prevention and cure of sickle cell anemia
• Prevention and cure of cystic fibrosis
• Production of clotting factors
• Production of insulin
• Production of recombinant pharmaceuticals
• Plants that produce their own insecticides
• Germ line and somatic gene therapy

Genetic  Engineering:

Genetic engineering alters the genetic makeup of an organism using techniques that introduce heritable material prepared outside the organism either directly into the host or into a cell that is then fused or hybridized with the host

Process:

1. Isolating the gene
2. Constructs
3. Gene treating
4. Transformation
5. Selection
6. Regeneration
7. Confirmation 

Genetically  Modified  Organism(GMO)

Fig:Genetically Modified Tomato

When a gene from one organism is purposely moved to improve or change another organism in a laboratory, the result is a genetically modified organism (GMO). It is also sometimes called transgenic.or transfer of genes.

Fig::Genetically Modified Maize

• Bt  corn
• Bt Cotton
• Bt brinjal
• Golden rice
• Long-lasting tomatoes
• Insecticide sweet corn
• Pesticide resistant rape plants

     BT:  Bacillus thuringiensis (Bt) is a spore forming (flash animation) bacterium that produces crystals protein (cry proteins), which are toxic to many species of insects.

 The  way of  Bt work:

  Bt has to be eaten to cause mortality. The Bt toxin dissolve in the high pH insect gut and become active. The toxins then attack the gut cells of the insect, punching holes in the lining. The Bt spores spills out of the gut and germinate in the insect causing death within a couple days.

Golden  Rice

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Fig:Golden  Rice

Golden rice is a variety of rice (Oryza sativa) produced through genetic engineering to bio synthesize beta-carotene,  a precursor of pro-Vitamin-A in the edible parts of rice. The scientific details of the rice were first published in 2000. Golden rice was developed as a fortified food to be used in areas where there is a shortage of dietary vitamin A.