Question: Assignment 7 – Northern Blot There Is A Eukaryotic Gene Of Interest (YFG) You Are Studying In Fruit Fles Which Has 3 Exons And 2 Introns. You Suspect That A Special Chemical Chemical X* Will Have A Regulatory Effect On The Expression Of YFG For Fruit Flies That Are Exposed To Chemical X. You Predict That Exposure To Chemical X Should Reduce Expression …

Assignment 7 – Northern Blot There is a eukaryotic gene of Interest (YFG) you are studying in fruit fles which has 3 exons and 2 introns. You suspect that a special chemical Chemical X* will have a regulatory effect on the expression of YFG for fruit flies that are exposed to Chemical X. You predict that exposure to chemical X should reduce expression of YFG when compared to pre-exposure conditions. Since extracting RNA from fruit flies is lethal, your best approach will be to raise 1000 fruit files from the same genetic line, divide the flies into two groups of 500 flies each. Extract total RNA from one group of flies that have not been treated with the chemical (the “before” group). And then expose the second group to Chemical X for the appropriate duration, followed by RNA extraction (the after group). Below on the left is a diagram of the pre-mRNA of YFG and the location where 3 different northern blot probes are designed to hybridize (probes a, b, and c). Probe a targets Intron 1. Probe bis a ‘split-probe where the first half of the probe is designed to hybridize to the end of Exon 2 and the last half of the probe is designed to hybridize to the beginning of Exon 3. And probe c targets Exon 3. Also below (on the right) are three blots (one for each of the three probos) and a GAPDH probed control for each lane. For each blot, you loaded a lane of total RNA from fruit Mies from the “before” group and a lane of total RNA from the “after” group. For comparison, all blots were lined up on to the same image next to a kb ladder, probes a 를 Exon 1 Exon 2 Exon 3 Intron 2 Intron 1 198 98 40 3.0 2.0 13 1. (3 pts) For each probe (a, b, and c.) what will using that probe will reveal in a northern blot? Here are some typical responses you might use pre-mRNA only. mRNA only, both pre-mRNA AND MRNA, or Nothing (it’s a useless probe), Probe a heals Probe breveals Probe e reveals – 2.(2 pts) What is the purpose of the GAPDH probe and evidence it shows 1.0 GAPOH 3. (1) Are any of the 3 blots untrustworthy regarding their data for YFG expression? If so which ono(s)? And why untrustworthy 4.12 pts) Was Chemical effective at reducing expression of pro-mRNA levels of YFG? What evidence do you have to draw that conclusion? 6.2 pts) Was Chemical effective at reducing expression of mRNA levels of YFG? What evidence do you have to draw that conclusion?