Molecular mechanism of hormonal signal transduction in plants Marc Meulener (UR '99) U.Penn MD/PhD Program Meulener@Mail.Med.UPenn.Edu

Project (Fall 1997 - Spring 1998)
An Efficient Way of Integrating DNA Into Plant Cells

Polyethylene Glycol (PEG) mediated transformation of plant cells has proven to be a very efficient (95%), and easy method to introduce genes into plant cells. However, the drawback is that most of the DNA introduced by this method is not able to integrate into the plant genome and hence will be degraded in a matter of a few days. On the other hand, Agrobacterium mediated gene transfer is the method of choice for stable incorporation of foreign genes into plant cells. However, this procedure is more time consuming and less efficient in obtaining a large number of transformed cells. Therefore, we attempt to combine the advantages of these two methods by using two genes from Agrobacterium in PEG mediated transformation to obtain high effeciency of DNA integration into plant cells. This new method should be quick and easy and will allow us to study effects of large numbers of genes on plant cell growth and differentiation.

Project (Fall 1996 - Spring 1997)
Phage-hypermodified DNA as a general means of avoiding restriction during transfer of DNA into bacteria

Genetic manipulation of bacteria is often difficult due to the presence of restriction enzymes, which cut all foreign DNA to pieces, making transduction or electroporation of plasmids into these bacteria very inneffective. One possible method that has been developed to combat restriction developed by Jeff Elhai utilizes the defense system of the bacteriophage T4 to protect DNA. Bacteriophage T4 hypermodifies the cytosines in its DNA, which results in the inability of most of the restriction enzymes of host cells to recognize its DNA. For the experiments, a previously constructed plasmid with a versatile origin of replication was used, and the method method was tested on several strains of E. coli bacteria as well as other bacteria such as Bacillus subtilis.

Presentations

Meulener M (1999). The Involvement of a MAPK Pathway in Auxin Signal Transduction. Arts and Sciences Student Symposium. University of Richmond.

Meulener M, Chiu WL, Chang H (1998). An efficient way to integrating DNA into plants. Arts and Sciences Student Symposium. University of Richmond.

Meulener M (1997). Using T4 Bacteriophage to Protect DNA from Restriction. Arts and Sciences Student Symposium. University of Richmond.