4-3.6. Applications of cDNA libraries/cloning
• Discovery of novel genes.
• in vitro study of gene function by cloning full-length cDNA.
• Determination of alternative splicing in various cell types/tissues.
• They are commonly used for the removal of various non-coding regions from the library.
• Expression of eukaryotic genes in prokaryotes as they lack introns in their DNA and therefore do not have any enzymes to cut it out in transcription process. Gene expression required either for the detection of the clone or the polypeptide product may be the primary objective of cloning.
• To study the expression of mRNA.
4-3.7. Disadvantagesof cDNA libraries
• cDNA libraries contain only the parts of genes found in mature mRNA. However, the sequences before and after the gene, for example, those involved in the regulation of gene expression, will not occur in a cDNA library.
• Construction of a cDNA library cannot be used for isolating the genes expressed at low levels as there will be very little mRNA for it in any cell type and may completely be out manoeuvred by the more abundant species.
Bibliography
Griffiths AJF, Miller JH, Suzuki DT et al. 2000. An Introduction to Genetic Analysis. 7th ed. W. H. Freeman. New York.
Lodge J. 2007. Gene cloning: principles and applications. Taylor and Francis Group.
Lodish H, Berk A, Zipursky SL et al. 2007. Molecular Cell Biology. 6th ed. W. H. Freeman.
Nicholl DST. 2008. An Introduction to Genetic Engineering. 3rd ed. Cambridge University Press.
Singh BD. 2008. Biotechnology: Expanding Horizons. 2nd ed. Kalyani Publishers.