Marine Biotechnology and Bioengineering in Puerto Rico

Edna Justiniano is originally from San German. Her previous education includes a B.S. in  Biology from Gordon College, an M.A. in Biological and Environmental Sciences from University of Bridgeport and an M.S. in Education from Western Connecticut State University .

She is currently a doctoral student at UPR Mayaguez and is interested in Marine Biotechnology/Bioengineering. Her work is described below:

Debaryomyces hansenii, a heterogeneous species with the capacity to grow in extreme environments including hypersalinity and heavy metals, is also an opportunistic pathogenic yeast associated with immunosuppressed patients such as HIV patients and patients having undergone surgery. This organism has also been isolated from cystic lesions, subcutaneous abscess associated with malignant melanoma, human skin, foot wounds and inter digital mycosis.  Environmentally induced gene expression and signaling pathways have been associated with several disease conditions such as cancer, rheumatoid arthritis, inflammation and neurological disorders. 

Our current research involves expression microarray-based analysis of salt induced genes, heterologous gene expression of specific promoters such as ENA-1, and whole genome comparison of D. hansenii strains showing different physiological responses after specific environmental stimuli. Whole genome sequencing allow for strain specific search of genes associated with the pathogenic response but it will also allow for the search of promoter differences. Some of the promoters will be isolated in order to develop varying heterologous expression systems.  Some of the responses governed by signaling pathways in D. hansenii include changes to the cell cycle, changes to polarized growth, and changes to the transcriptional profile of the cell. Since these types of changes often trigger cancer in mammalian cells, understanding how these genes function will provide insight into how pathways function. 

 Whole genome expression analysis will identify genes that are expressed differentially in response to stress while whole genome sequencing will provide results on how different strains vary in gene structure and hence function in response to different environmental conditions since previous studies in our laboratory have indicated that different natural strains of D. hansenii respond differently to environmental stimuli. Sequencing of some of the genes that are differentially expressed show sequence variability exists among natural isolates of this organism.