The development of cotton fiber may be studied as a system of carefully controlled cellular differentiation. Elucidation of the molecular processes involved in this system may lead to further understanding of general mechanisms of control of cellular development and differentiation. Since the synthesis of specific proteins must be required for the development of a cell of a specific type, one approach to the study of the control of differentiation is to examine the control of the production of proteins. Two general levels of regulation of protein production are the regulation of the transcription of the mRNA which codes for the protein, and the regulation of the translation of that mRNA into the protein. These levels of control may be examined by their inhibition through the use of drugs which inhibit specifically transcription or translation.