MBB 201 Lecture Notes - Lecture 17: Transposase, Mobile Genetic Elements, Synteny

51 views3 pages

harlequinweasel561

29 May 2018

School

Simon Fraser University

Department

Molecular Biology and Biochemistry

Course

MBB 201

Professor

Frederic Pio

For unlimited access to Class Notes, a Class+ subscription is required.

Chapter 9: How Genes and Genomes Evolve

Generating Genetic Variation

Types of Genetic Change

• Mutation within a gene

o Changes a nucleotide

o Deletes or duplicates more than one or more nucleotides

o Alter splicing of transcript, and change stability, activity, location and interactions

• Mutation within a regulatory DNA

o How a gene is expressed can be affected by mutations within regulatory

sequence of nucleotides

• Gene duplication

o An existing gene, large segment of DNA or a whole genome is duplicated

o Duplications can acquire additional mutations leading to new functions and

patterns of expression

• Exon Shuffling

o Two or more genes are broken down and rejoined making a hybrid gene

o In eukaryotes usually occurs within introns so have no affect on functional genes

• Horizontal gene transfer

o Piece of DNA transferred from genome of one cell to that of another

o Common among bacteria

o Vertical- parent to progeny

Sexually Reproducing Organisms

• In asexual- inheritance of genetic information is direct from parent. Each organism is like

its ancestors

• Germ cells -specialized reproductive cells

o Cary copy of its genome

• Somatic cells- all other cells in the body

o Die without evolutionary descendants of their own

o Only help germ cells survive and propagate

o Mutations do not transfer to offspring

• Germ line- cell lineage giving rise to germ cells

• A mutation in the germ cell will be passed to offspring

• Offspring produced are genetically distinct from each parent

Point Mutations

• Point mutations- affect one single nucleotide pair

• Arise from rare errors in DNA replication or repair

• Mutations can be discovered by exposing organism to one select condition

• Can destroy or improve the activity of a gene

o Usually doesn’t do either- neutral mutation

• Ability to digest milk is due to a point mutation that arose thousands of years ago

New families of Genes

• When a gene duplicates two copies now exist to be mutated

• Can acquire mutations as long as the original function of the gene is not lost

• Termed gene duplication and divergence

find more resources at oneclass.com

Unlock document

This preview shows page 1 of the document.
Unlock all 3 pages and 3 million more documents.

Already have an account? Log in

Document Summary

In eukaryotes usually occurs within introns so have no affect on functional genes: horizontal gene transfer, piece of dna transferred from genome of one cell to that of another, common among bacteria, vertical- parent to progeny. In asexual- inheritance of genetic information is direct from parent. Exon shuffling: exon shuffling- when exons from one gene are added to another within a domain, results in hybrid genes. Horizontal gene transfer: genes exchange between individuals of different species. Homologous genes- similar in composition due to common ancestor: analysis helps uncover evolutionary history. Keeping mutations: mutations that prove advantageous are most likely to be inherited, mutations that have no affect (selectively neutral) on the organism might be passed, mutations that are harmful will be lost. Phylogenetic tree: a diagram depicting the evolutionary relationships among a group of organisms. Retrotransposons: move via rna intermediate, found only in eukaryotes, l1, alu sequence.

Related Questions

Match the type of phenotypic change between the type of Gene and chain you're most likely to cause it. Each type of Gene and change may be used more than once or may not be used at all.

phenotypic changes
1. A protein normally localized in the nucleus is not localized in the cytoplasm
2. A protein acquires a DNA binding domain
3. Tandem copies of a gene are found in the genome.
4. A copy of a bacterial Gene is now found integrated on a human chromosome.
5. A protein becomes much more unstable
6. A protein normally expressed only in the liver is now expressed in blood cells.

A. mutation within a gene
B. Gene duplication
C. mutation in a regulatory region
D. Exon shuffling
E. horizontal Gene transfer

could I get some help with this problem I'm not too sure about my answers thank you

coffeepig339

Cystic fibrosis is caused by mutations in the CFTR gene, whichencodes for a chloride channel. You are studying cystic fibrosispatients to determine what mutation they possess in the CFTR gene.The difference between the mutant and wild type CFTR genes can beuncovered by examining the CFTR:

(1 point - partial possible)

DNA

mRNA

protein

You decide to identify the CFTR mutation by analyzing thegenomic DNA of your patients compared to genomic DNA of healthyindividuals. You specifically are looking to see whether a specificgene truncation has occurred in the patients. You will determinethis using hybridization techniques. Which of the following willallow you to accomplish this?

(1 point - partial possible)

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

Using an RNA probe complementary to the region removed by thetruncation.

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

Using an DNA probe complementary to the region removed by thetruncation.

You would like to ensure that this experiment (to determinewhether patients have a specific CFTR gen truncation usinghybridization) is properly controlled. Which of the followingsamples must you include?

(1 point - partial possible)

The genome of a healthy individual who does not have CFTR.

The genome of a CFTR patient known to have the specifictruncation you are trying to identify.

The genome of a CFTR patient with a point mutation in a separateregion of the gene but without the disease truncation.

The genome of a healthy individual married to a CFTR patientwith the specific truncation you are trying to identify.

The genome of a patient with muscular dystrophy, which can bedue to a trucation in the dystrophin gene.

To conduct the hybridization experiment, you are trying todecide between using a DNA or RNA probe. Which would be a betterchoice and why?

(1 point)

An RNA probe because RNA has uracil bases.

An RNA probe because it could also be used in a translationexperiment.

A DNA probe because it is more stable than RNA.

A DNA probe because RNA cannot bind to DNA.

Which of the following will lower the Tm of a given DNAstrand?

(1 point - partial possible)

Increasing the percentage of GC base pairs.

Raising the pH of the solution from extremely acidic toneutral.

Decreasing the salt concentration in the DNA solution from 50mMNaCl to 5mM NaCl.

None of the above.

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

(1 point)

A.No, because only DNA can be labeled with radioactivity.

B.No, because the RNA genome would not enter the bacteria uponinfection.

C. No, because while DNA and RNA nucleotides are similar, theyare not identical.

D. Yes, because DNA and RNA nucleotides are similar.

Griffith and Avery's transformation experiments allowed us toidentify that DNA is our genetic information. Which of thefollowing scenarios would result in bacterial cells that arecapable of killing mice upon injection?

(1 point - partial possible)

A. Heat killed non-virulent bacteria is added to a live virulentbacteria strain.

B. Heat killed virulent bacteria is added to a heat killednon-virulent bacteria strain.

C. A heat killed virulent bacteria that is treated with anuclease, is then added to a non-virulent bacteria strain.

D.Heat killed mouse cells are added to a non-virulentbacteria.

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

(1 point - partial possible)

A. Random DNA mutations generally won't affect RNA and proteinfunction.

B. It is faster to duplicate the genome when these arepresent.

C. The existence of introns can lead to multiple variations ofproteins encoded by a single gene.

D. Abundant non-coding genome is a protective feature againstthe consequences of transposition of mobile elements.

bronzewater-buffalo862

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

MBB 201 Lecture Notes - Lecture 17: Transposase, Mobile Genetic Elements, Synteny

Document Summary

Get access

Related Documents

MBB 201 Lecture Notes - Lecture 1: Central Dogma Of Molecular Biology, Bright-Field Microscopy, Macromolecule

BIL 255 Lecture 9: Chapter 9 - Gene and Genome evolution

CAS NE 102 Lecture Notes - Lecture 7: Exon Shuffling, Noncoding Dna, Intron

Related Questions