Open Collections

A fuctional [sic] analysis of Cis-elements contributing to developmental regulation of gene expression by the 4CL1 promoter in transgenic tobacco plants

University of British Columbia

It has been widely noted that elucidating the mechanisms by which eukaryotic organisms control the timing and location of the expression of particular genes is one of the central problems of developmental biology. This thesis is intended to contribute to an understanding of the mechanisms by which one promoter, that of the parsley 4-coumarate:CoA ligase 1 (4CL1) gene, directs expression of attached protein-coding sequences in developing tobacco plants. In tobacco, 227 base-pairs of the parsley 4CL1 promoter are sufficient to direct a complex pattern of developmentally-regulated gene expression (Hauffe et. al., 1991). Within this region, six sequences have been identified as possible sites of protein-DNA interaction in parsley cell culture (Ibid). In order to test whether these sequences are cis-elements contributing to the developmental regulation of 4CL1- directed gene expression, these sequences were mutated and the effects on expression of a reporter gene examined in different organs and cells of transgenic tobacco plants. Results discussed in this thesis strongly indicate the presence of at least four developmentally-important elements within the tested sequences. While mutation of each element effected expression quantitatively, each element exhibited different cell- and organ-specificities in its influence on gene expression. The identified elements include both positive and negative regulators of gene expression. Expression patterns directed by the 4CL1 promoter when mutated at multiple sites suggest that the examined elements are in some cases interdependent, requiring other elements in order to function. One element, the footprint 5/6 element, may play a particularly important role in these interactions. Taken together, these observations identify developmentally-important cis-elements in the 4CL1-promoter and provide insights into the mechanisms by which they function.

Thesis/Dissertation

application/pdf

2009-04-20

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

http://hdl.handle.net/2429/7437

Botany

University of British Columbia

UBCV

DSpace