Ntesfaio Week 11
Contents
Purpose
10 Terms
Outline of your journal article
The purpose of this paper was to observe how Saccharomyces cerevisiae responded to arsenite. This was analyzed by quantitative transcriptome, proteome, and sulfur metabolite. Arsenite exposure can be toxic as it affects transcription in genes which is necessary for protein synthesis. Arsenic is highly toxic and is a risk to human health as well as the environment. Arsenic has been known to poison humans, as seen in Bangladesh and West Bengal where a epidemic of arsenic poisoning occurred as it contaminated drinking water. Chronic exposure can cause cardiovascular disease, neurological disorders, and liver injury. It is also associated with cancers of the skin, bladder, liver, and lung. As organisms because more exposed to arsenite there has been an evolution. Sulfur assimilation in yeasts in performed by having sulfate taken up and metabolized through a sulfate assimilation pathway. The sulfide goes through two possible pathways: the methyl cycle or the glutathione cycle. Glutathione (GSH) is a key factor in a cell's defense of metal toxicity. The metals used were sodium arsenite, cadmium chloride, and potassium antimonyl tartrate. Yeast strains were grown at 30 degrees Celsius on YNB mediums. RNA was isolated from the yeast cells that had been exposed to arsenite.
What is the importance or significance of this work?
Results showed that exposure to sodium arsenite of different concentrations yielded different effects. Cells exposed to 0.2 mM had a moderate effect on growth while those with 1 mM were severly affected.
What were the limitations in previous studies that led them to perform this work? What strain(s) of yeast did they use? Were the strain(s) haploid or diploid? What media did they grow them in? What temperature? What type of incubator? For how long? What controls did they use? How many replicates did they perform per treatment or timepoint? What method did they use to prepare the RNA, label it and hybridize it to the microarray? What mathematical/statistical method did they use to analyze the data? Are the data publicly available for download? From which web site? Briefly state the result shown in each of the figures and tables, not just the ones you are presenting. What do the X and Y axes represent? How were the measurements made? What trends are shown by the plots and what conclusions can you draw from the data? How does this work compare with previous studies? What are the important implications of this work? What future directions should the authors take? Give a critical evaluation of how well you think the authors supported their conclusions with the data they showed. Are there any major flaws to the paper?
