Genetically Modified Birds

3. 
Production of Recombinant DNA: A restriction enzyme scans the vector e.g. plasmid‟s double helix 
unit and recognizes a particular sequence of bases. It opens the plasmid in a staggered fashion, leaving four 
bases hanging from each cut strand. The four base link up loosely with the complementary bases on the open 
isolated DNA molecule. Next, the enzyme DNA ligase joins the sugar-phosphate backbones of the plasmid and 
isolated DNA. 
4. 
Selection of Host Cell: the host is the organism to be transformed. They range from microorganisms to 
mammals. Microorganisms are transformed so that they can be able to be used in the industries to produce 
metabolites. Some hosts are; E. coli, Bacillus subtilis, Saccharomyces cerevisiae(yeast) and mammalian cells 
[6]. 
 
DNA Insertion Methods 
(a) 
Microinjection: this is one widely used DNA procedure for DNA insertion. A microscopic syringe is 
used to penetrate the cell wall and plasma membrane of the plant cell and propel DNA fragments into the 
nucleus. Only one cell at a time can be injected and 10,000 or more injections may be required before a 
successful DNA incorporation to the cell‟s nucleus is made. 
(b) 
Biological Biolistic (Biolistic): this was developed by Cornell university. Biolistic consists of a 
cylinder with a catrige containing a nylon projectile. The projectile carries millions of microscopic tungsten 
spheres, each sphere coated with DNA. When the catridge is fired at a colony of cells, the projectile shoots 
down the cylinder and a steel placed at the end of the cylinder stops all but the gene carrying spheres. The high 
velocity and tiny size of spheres speed their entry into the cytoplasm of the cells. This method is costly and the 
cellular damage is high. 
 (C). Transfection: this is done by infecting the host cell with the recombinant DNA.
(d). Vortex mixing is another technique that has been developed [7]. 

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Genetically Modified Birds 
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