BPS 3101 Lecture Notes - Lecture 3: Restriction Site, Immunoprecipitation, Epigenetics

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tealgerbil756

11 Nov 2017

School

University of Ottawa

Department

Biopharmaceutical sciences

Course

BPS 3101

Professor

Christopher Boddy

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Document Summary

So looking at different tissues and check if gene x is expressed so by probing these different tissue and see if a certain gene is present in them or not. This is not always on gel, this kind of probing with a complimentary tag something that has reverse compliment sequence. This also (cid:272)a(cid:374) (cid:271)e do(cid:374)e i(cid:374) histologi(cid:272)al sa(cid:373)ple su(cid:272)h as(cid:863) i(cid:374) itu h(cid:455)(cid:271)ridizatio(cid:374) (cid:862)so it (cid:272)a(cid:374) (cid:271)e used for northern to probe a slice of tissue and identify where a particular gene is expressed. Radioa(cid:272)ti(cid:448)e is ofte(cid:374) used to see if it"s e(cid:454)pressed. Radioactivity is often used to make it sensitive enough, sulfur labelled antisense probe is used to look at heart ventral syndrome in embryonic mouse. Southern blot which is looking for dna, probing with dna sequence. This blot is used to identify proteins rather than dna or rna.

Related Questions

1. A study was conduced to identify a liver cell gene (zed) that has a length of 3000 bp. A southern blot was prepared using DNA from the liver cell and a probe made to region 1600-2000 of zed. Analysis of the blot revealed that there are two spots present, one at 3000 and another at 2000. A plausible explanation for this observation is

A. there is an identical copy of this gene on another chromosome.

B. the gene was cut into two equal portions by a restriction enzyme.

C. there is another gene with sequence similar to gene zed

D. both: there is an identical copy of this gene on another chromosome and there is another gene with sequence similar to gene zed

E. no explanation can be given using the available data

2. Protein P is synthesized in relatively high amounts in human pancreas. This protein has been isolated and purified, but its amino acid sequence has not been determined. We wish to clone the gene for protein P.

(a) How can a probe be prepared to identify the gene for protein P?

(b) If we have prepared a radioactive messenger RNA as our probe in part(a), how could we verify that it is the mRNA for protein P?

(c) If we wish to make a gene library from the DNA of human pancreatic cells, we proceed by digesting the DNA with the restriction enzyme BamHI and then separating the fragments by agarose gel electrophoresis. The fragments are transfered (by southern blotting) onto a nitrocellulose filter and flooded with the radioactive probe. Following incubation, the filter is washed to remove any probe that has not specifically bound to one or more DNA fragments. Autoradiography of the filter reveals two bands of size 300 and 700 bp. When experiment is repeated using restraction enzyme PstI, only one band of 1000 bp appears. If it is already known that pancreatic cells contain a single copy of the gene of protein P, which of these enzymes should be used to construct our gene library?

violethornet799

Question 1

1 pts

Cystic fibrosis is caused by nonsense and missense mutations in the CFTR gene, which encodes for a chloride channel. You are studying cystic fibrosis patients to determine what mutation they possess in the CFTR gene. The difference between the mutant and wild type CFTR genes can be uncovered by examining the CFTR:

	DNA
	mRNA
	protein
	tRNA

Question 2

1 pts

You decide to identify the CFTR mutation by analyzing the genomic DNA of your patients compared to healthy individuals. You specifically are looking to see whether a specific 3' gene truncation has occurred in the patients. You will determine this using hybridization techniques with samples from healthy and CF patients. Which of the following will allow you to accomplish this?

	Using an RNA probe complementary to the region not removed by the truncation.
	Using an RNA probe complementary to the region removed by the truncation.
	Using an DNA probe complementary to the region not removed by the truncation.
	Using an DNA probe complementary to the region removed by the truncation.

Question 3

1 pts

You would like to ensure that this experiment (to determine whether patients have a specific CFTR gene truncation using hybridization) is properly controlled. Which of the following samples must you test?

	The genomic DNA of a healthy individual who does not have cystic fibrosis.
	The genome of a CFTR patient known to have the specific truncation you are trying to identify.
	The genome of a CFTR patient with a missense mutation but full length gene.
	The genome of a healthy individual married to a CFTR patient with the specific truncation you are trying to identify.
	The genome of a patient with muscular dystrophy, which can be due to a trucation in the dystrophin gene.

Question 4

1 pts

To conduct the hybridization experiment, you are trying to decide between using a DNA or RNA probe. Which would be ideal to use and why?

	As both are composed of nucleic acids, using either would result in identical results.
	An RNA probe because RNA has uracil bases.
	An RNA probe because it could also be used in a translation experiment.
	A DNA probe because it is more stable than RNA.
	A DNA probe because RNA cannot bind to DNA.

Question 5

1 pts

Which of the following will lower the Tm of a given DNA strand?

	Increasing the percentage of GC base pairs.
	Raising the pH of the solution from neutral to basic.
	Decreasing the buffer concentration from 50mM NaCl to 5mM NaCl.
	None of the above.

Question 6

1 pts

One step of the Hershey/Chase experiment involved blending the virus/cell mixture before centrifugation and probing the pellet for radioactivity. Why was the blending step necessary?

	To collect the bacteria at the bottom of the tube.
	To break open the bacteria to release the genome.
	To separate the bacteria from the bacteriophages.
	To be able to detect the radioactivity.

Question 7

1 pts

Imagine Hershey/Chase had used an RNA virus (genome composed of RNA) instead of a DNA virus in their experiment. Would radioactivity still have been found in the pellet?

	No, because only DNA can be labeled with radioactivity.
	No, because the RNA genome would not enter the bacteria upon infection.
	No, because while DNA and RNA nucleotides are similar, they are not identical.
	Yes, because DNA and RNA nucleotides are similar.
	Yes, because genome in any form (DNA, RNA, protein) would be labeled similarly.

Question 8

1 pts

Griffith and Avery's transformation experiments allowed us to identify that DNA is our genetic information. Which of the following scenarios would result in bacterial cells that are capable of killing mice upon injection?

	Heat killed non-virulent bacteria is added to a live virulent bacteria strain.
	Heat killed virulent bacteria is added to a heat killed non-virulent bacteria strain.
	A heat killed virulent bacteria that is treated with a nuclease, is then added to a non-virulent bacteria strain.
	Heat killed mouse cells are added to a non-virulent bacteria.

Question 9

1 pts

The human genome consists mostly of non-coding DNA. Which of the following are benefits of this?

	Random DNA mutations generally won't affect RNA and protein function.
	It is faster to duplicate the genome when these are present.
	The existence of introns can lead to multiple variations of proteins encoded by a single gene.
	It is unlikely transposons would exist in the genome if there was too much protein coding DNA.

Question 10

1 pts

Andrew Murray's sister, Andrea, is adding to her brother's work on chromosomes. She is using cells that are unable to synthesize adenine (âade) and histidine (âhis). The plasmid she is currently working with consists of an origin of replication and the Ade gene.

Following her transformation of the plasmid into her yeast, what media will the cells be plated on to select for cells that have picked up the plasmid?

	Media containing histidine
	Media containing adenine
	Media lacking adenine
	Media lacking histidine

tealcockroach755

Multiple answers to each question might be possible!

	Using an RNA probe complementary to the region not removed by the truncation.
	Using an RNA probe complementary to the region removed by the truncation.
	Using an DNA probe complementary to the region not removed by the truncation.
	Using an DNA probe complementary to the region removed by the truncation.

To conduct the hybridization experiment, you are trying to decide between using a DNA or RNA probe. Which would be ideal to use and why?

	As both are composed of nucleic acids, using either would result in identical results.
	An RNA probe because RNA has uracil bases.
	An RNA probe because it could also be used in a translation experiment.
	A DNA probe because it is more stable than RNA.
	A DNA probe because RNA cannot bind to DNA.

One step of the Hershey/Chase experiment involved blending the virus/cell mixture before centrifugation and probing the pellet for radioactivity. Why was the blending step necessary?

	To collect the bacteria at the bottom of the tube.
	To break open the bacteria to release the genome.
	To separate the bacteria from the bacteriophages.
	To be able to detect the radioactivity.

Imagine Hershey/Chase had used an RNA virus (genome composed of RNA) instead of a DNA virus in their experiment. Would radioactivity still have been found in the pellet?

	No, because only DNA can be labeled with radioactivity.
	No, because the RNA genome would not enter the bacteria upon infection.
	No, because while DNA and RNA nucleotides are similar, they are not identical.
	Yes, because DNA and RNA nucleotides are similar.
	Yes, because genome in any form (DNA, RNA, protein) would be labeled similarly.

The human genome consists mostly of non-coding DNA. Which of the following are benefits of this?

	Random DNA mutations generally won't affect RNA and protein function.
	It is faster to duplicate the genome when these are present.
	The existence of introns can lead to multiple variations of proteins encoded by a single gene.
	It is unlikely transposons would exist in the genome if there was too much protein coding DNA.

Explain the 5â to 3â directionality of a DNA stand.

	It is due to the fact that the free 5â carbon is on one end and the free 3â carbon is on the other
	It is due to the fact that new nucleotide are added to the 5â carbon of the previous nucleotide
	It is due to the fact that there are 3 phosphate groups attached to the 5â carbon
	It is due to the fact the complementary strand is 3â to 5â
	More than one of the above explain the 5â to 3â directionality

You accidentally add a mutant dNTP (which has an H instead of an OH connected to the 3â carbon) to a reaction where DNA is being replicated. Which of the following is true of this mutant dNTP?

	It can be incorporated into DNA strand but cannot form a phosphodiester bond with an incoming wild type dNTP
	It can be incorporated into a DNA strand but cannot base pair with a complementary nucleotide
	It can be incorporated into a DNA strand and can form a phosphodiester bond with an incoming dNTP, but only if it is another mutant dNTP
	It cannot be incorporated into a DNA strand.

Why does DNA polymerase utilize an RNA primer?

	DNA polymerase is unable to initiate strand synthesis but RNA polymerase can
	DNA polymerase can only add a dNTP to an rNTP
	DNA synthesis proceeds in the 3â to 5â when initiating strand synthesis
	Chromosomal DNA contains interspersed RNA fragments
	The RNA primer increases stability of the newly synthesized strand

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BPS 3101 Lecture Notes - Lecture 3: Restriction Site, Immunoprecipitation, Epigenetics

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