Question

problem that can be solved by one or more of gene manipulation techniques for example PCR

Answer 1

Polymerase chain reaction was discovered by Karry Mullis in 1985. Now this technique has been used in several scientific approaches especially in genotyping studies were it is use to find true segregants among large population. But the applicability of PCR technique is much wider then it was assumed initially.

PCR technique has been indispensably used in genome editing techniques. The first evidence was  came in 1970 from the editing of a microbe E.coli that has very small genome size and fast generation time, this has lured researcher to use these microbe as model organism to understand and characterize the function of gene. Later, this technique was used to creat mutation in the fruit fly Drosophila, which has comparatively smaller genome and shorter generation time. Now mice has been extensively used for gene knockout study for gene function characterization. Till date, more than thousand gene knockout mice has been created, the actual motive to create knockout for each and every gene which will will allow researcher to understand the role and regulation of each and every gene in complex eukaryotic system, especially in mammals. PCR provide simple technique to identify genetically modified animals and crop by simple approach i.e., amplifying desired transgene in the putative transgenic organism.

By modifying a gene using specially designed primers for site directed mutagenesis causing either knockout or missense mutations. The knockout approach provide gene function and its impact on the organism phenotype or in a pathway. However, often missense mutations were created to study the role of the amino acid (active site) on enzyme activity, effect on the phosphorylation, and promoter analysis (specifically in eukaryotes)

Till date, PCR technique has been used to amplify desired transgene/ or gene fragment or its cDNA and ligate them to the construct which was further used for agrobacterium mediated transformation in plants. This PCR technique can also be used to identify the genetically transformed transgenic plant by amplifying the trans - resistance gene or herbicide resistance gene which being introduced through agrobacterium. Similarly, real time quantitative PCR are being used to used transgenic RNAi silenced plants by amplifying the transcript of silenced gene. The reduced expression of the transcript suggest the level of silencing. Now several crops has been genetically edited/modified. In Canada, because of success story of PCR and its role in genome editing, genetic modified canola with very high percentage of health beneficiary oleic acid is available to public. In plant, Arabidopsis, tobacco and tomato are frequently used for genome editing for understanding complex genetic regulation in plant for crop improvement. Till date, several organism has been genetically modified  using PCR, including zebra fish, pig, mice. Recently, this approach has been used to develop transgenic sterile mosquitoes which can help in reducing mosquito population as well as the diseases associated with them.