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It has been a pleasure to be guided, motivated and supported by the two most wonderful people I have ever met, Dr. Ram V. Devireddy and Dr. Tryfon T. Charalampopoulos, and to whom I dedicate this thesis. I would like to thank my advisor Dr. Ram V. Devireddy for introducing me to the field of Biotechnology, by giving me a chance to work on such an intriguing problem and for the technical insight he has provided. I would like to thank my co-advisor Dr. Tryfon T. Charalampopoulos for inculcating in me the morals of research and always encouraging me to work hard as a graduate student. Next I would like to thank Dr. Michael C. Murphy for being my committee member and for his time and expertise to evaluate my thesis