Please answer each question completely (all parts)! Thank you!! In an attempt to
ID: 68926 • Letter: P
Question
Please answer each question completely (all parts)! Thank you!!
In an attempt to identify genes upregulated in an Aspergillus strains forced to grow on phenylalanine as its sole carbon source, how and why did the authors convert all the mRNA from strain 2 into single stranded cDNA? Specifically, list the basic essential reagents (specific nucleotides, template and enzyme) that would be needed to do the conversion). Why was it important to convert all the mRNA from strain 2 into cDNA in order to accomplish their goal (See bold text above): In a Northern analysis, one is attempting to measure the steady state level of what molecule: Lipids Amino acids Protein mRNA genomic DNA In a Northern analysis, one also needs a probe (radioactively or fluorescently labeled). The authors here had mRNA or single stranded cDNA corresponding to the hmgA gene? EXPLAIN. Either could work as a probe. Only the cDNA will work. Only the mRNA will work. In the FISH technique described later, the authors attempted to localize the position of the human hmgA gene on human chromosomal DNA. Again a probe was necessary (here they used a fluorescently labeled probe) and again they had mRNA or single stranded cDNA corresponding to the hmgA gene. EXPLAIN. Either could work as a probe. Only the cDNA will work. Only the mRNA will work.Explanation / Answer
Q11. They converted all the mRNA into ssDNA so that they could use it as a probe for analysis of gene expression on a microarray. A difference in the gene expression pattern will reveal which genes are upregulated when Aspergillus grows on phenylalanine and other amino acids. The template used would be the mRNA and the enzyme would be reverse transcriptase.
Q12. f. mRNA. Northern blotting is a method to detect mRNA.
Q13. h. Either could work as a probe. Both mRNA and DNA are used as a probe. They may be hapten-labelled or radio labelled).
Q14. k. Either could work as a probe. Since the principle of hybridization is same, both could work as a probe with appropriate label.