“ The Discovery of Reverse Transcriptase” November 2, 2010 Biology 161 Dr. Hong Fei By: David...
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Transcript of “ The Discovery of Reverse Transcriptase” November 2, 2010 Biology 161 Dr. Hong Fei By: David...
“The Discovery of Reverse Transcriptase”
November 2, 2010
Biology 161Dr. Hong Fei
By: David MeyerKylene Wolfe
Ryan SchramerAdrian Bachman
History
Genetic information was demonstrated through the transfer of information of the
biological system during the years of:
1940's, 1950's & 1960's
In 1970 more of a focus on RNA tumor viruses but left many unanswered
questions.
Howard Temin
Studied RNA tumor viruses most of his life
His early days he spent time working on Rous sarcoma virus (RSV)
Temin was the one that came up with the first
hypothesis for the study of Reverse
Transcriptase
Howard Temin Proposal
“RSV is sensitive to inhibitors of DNA synthesis and suggesting that DNA, complementary to the RSV genomic
RNA, is present in transformed cells.”
David Baltimore
Spent time studying virus replication
He looked at RNA and DNA at a more
biochemical view looking deep within individual
virions
He later focused on RNA tumor viruses and
concluded with Rauscher murine
leukemia virus (R-MLV)
Experiment Time!
They disrupted their pure stock viruses by using nonionic detergents
“Can a retrovirus perform DNA synthesis?”
Then “radiolabeled deoxthymidine triphosphate (dTTP) along with three deoxynucleotide triphosphates (dATP,
dCTP, dGTP) to the virion preparation.”
Did these reactions contain any incorporation of radioactive dTTP into DNA?
YES!Each experiment, dTTP turned into nucleic acid
One more test!
Baltimore and Temin both “preincubated the virions with RNase, which catalyzes the
degradation of RNA into ribonucleotide monophosphates.”
Results:
“The longer the pretreatment of virions with RNase, the lower the
amount of DNA-synthesizing activity, - thus an enzyme in the
virion could catalyze RNA-dependent DNA synthesis.”
Results/Data
Demonstration of RNA-dependent DNA Synthesis
Radioactive Tymidine Incorporated into Nucleic Acid
Experimental Treatment: R-MLV RSV
Standard Conditions 3.69 pmol 9110 dpm Virions pretreated with RNase 0.52 pmol 2650
dpm
Untreated Product 1425 dpm 8350 dpmAfter product is treated with RNase 1361 dpm 7200 dpmAfter Product is treated with Dnase 125 dpm 1520 dpm
This was reverse to what normally was happened in DNA and RNA giving it's name:
“Reverse Transcriptase”
Conclusion:
Temin believed that his hypothesis was true all along he just had to prove it to the world
Baltimore believed a different theory but tested Temin theory by checking RNA-dependent and DNA polymerization.
What has this done to help the world?
Concert mRNA to DNA help create cDNA libraries
coloning and study of tissuesstudy of many genes throughout biology
Explosion of research in retroviruses/ RNA viruses
Temin/Baltimore Future
Since HIV-AIDS is a retrovirus! This drove Temin and Baltimore to
a Noble Prize in 1975
QUIZ TIME!!!
1. Why was the research done?
a. Win a Noble prizeb. Become president
c. To test whether or not RNA genome of RSV is converted into a DNA provirusd. Test Michael Jackson's DNA
Question 2
2. What method did these men use?
a. Newton's Law methodb. Broke down a virus and started doing
DNA/RNA test on itc. Dr. Fei Method
d. Heartland College Education Method
Question 4
4. What could you conclude from this experiment?
a. It was the worlds greatest experimentb. The longer the pretreatment of virions with RNase, the
lower the amount of DNA-synthesizing activity, - thus an enzyme in the virion could catalyze RNA-dependent
DNA synthesis.”c. If water goes up, it must come back down
d. DNA/RNA is the same in all people
Question 5
5. What is one way this research has helped the world?
a. It helped two men win a Noble Prizeb. It's going to save the world
c. It gave a cure to AIDSd. Explosion of research in retroviruses/ RNA
viruses
Bonus Question
Who is the greatest Biology instructor in the who world?
a. Dr. Hong Feib. President Obamac. Rod Blagojevich
d. Police Officer