Introduction

    Microarray technology allows for the analysis of genomes for use in detecting changes in gene expression to observe possible mutations in the DNA.  Using complementary base pairing of labeled cDNA to DNA sequences on a microarray chip the expression levels of many genes can be determined.  Although microarray technology is a relatively new technique used in research, its future uses are infinite.  Research opportunities are vast, ranging from using microarrays to figure out how to make the perfect wine to using them to cure cancer. 

                The basis of life of all eukaryotic cells is the sugar molecule; eukaryotes rely on the metabolism of the major hexoses glucose, fructose, and galactose. (1)  Because of their size and other physical characteristics, hexoses can not directly diffuse across the cell membrane and therefore must be actively transported by the use of hexose transporters.  The strain of yeast used in this experiment was Saccharomyces cerevisiae, which has twenty different genes specific for hexose transporter protein production.  The regulation of the proteins for the transporters is determined by the levels of sugars present in the cellular environment.  The type of hexose transporter genes that are turned on is directly determined by the type of sugar that is present. 

        In this experiment the expression levels of both the wild type (Cen) and mutant (EBY) phenotypes of the yeast that were obtained from Dr. Janet Daniel were determined; the wild-type strain is representative of a typical yeast culture and the mutant strain is lacking all hexose transporters.  The gene expression levels were measured by analyzing the ratio of red (Cy5) dye to green(Cy3) dye.  If the dye on the microarray chip fluoresced predominantly red, then it meant that there was an up-regulation of the gene in the mutant and if it fluoresced predominantly green, than there was an up-regulation in the wild-type.  

http://www.vetmed.iastate.edu/faculty_staff/users/phillips/Micro402/17-genomics/microarray.htm

        By comparing our microarray data to many other microarray analysis done by other groups, several questions were formed about the development of possible trends among the data:

1.     Are there any other genes present in the wild type strain that are not present in the mutant strain?

2.   By viewing the expression levels of the wild type yeast versus the mutants, which genes are over expressed and which are under expressed?

3.  How does the cell compensate for hexose transport and metabolic pathway genes being knocked out?   

        Home        Methods        Results        Discussion

1.  Johnson, M and Özcan, S.  "Function and Regulation of Yeast Hexose Transporters"  1999.  Microbiology and Molecular Biology Reviews. September 1999.                                                            

           <http://mmbr.asm.org/cgi/content/full/63/3/554>