ACKNOWLEDGMENTS

 This dissertation would not have been completed without the knowledge, guidance and

dedication of Dr. Peter J. Hansen, chair of my supervisory committee. I am very grateful for the

opportunity to complete this dissertation under Dr. Hansen's supervision and I truly appreciate

his enthusiasm for science as well as his seemingly endless patience. Dr. Hansen has been

extremely supportive of my career ambitions and for his generous help I am deeply indebted.

Dr. Hansen has been an excellent mentor and will continue to be a great friend. Appreciation is

also extended to the other members of my supervisory committee: Dr. William C. Buhi, Dr.

Kenneth C. Drury, Dr. Karen Moore, and Dr. James L. Resnick. This is a talented group of

people and I feel fortunate to have been able to work with them. I would like to thank each of

these members for their tremendous insight and knowledge. Moreover, I am also grateful for

their accessibility and willingness to help, as well as their encouragement and support during the

completion of this dissertation.

 Much of the research in this dissertation required a tremendous amount of help from other

graduate and undergraduate students in the Hansen laboratory, including Dr. Dean Jousan, Luiz

Augusto de Castro e Paula, Charlotte Dow, Amber M. Brad, Amy Fischer-Brown, Lauren

Bamberger, Rodrigo Nunes, Moises Franco, Lilian Oliveira, Barbara Loureiro, Maria B. Padua,

Adriane Bell and Patrick Thompson. I am truly grateful for their assistance with my research as

well as their camaraderie in the lab. It was a pleasure working with such a diverse and fun-

loving group of people. I would also like to thank Dr. Todd Bilby, Flavio Silvestre and Steaven

Woodall, members of other laboratories who were always willing to help with my projects.

 The analysis of mRNA abundance was done in collaboration with Dr. Christine Wrenzycki

and Dr. Heiner Niemann of the Institute for Animal Science in Neustadt, Germany. In addition,