LAB - Genetic transformation - making E. coli glow and survive ampicilin

Genetic transformation is the process through which a cell takes up, and expresses, a new piece of genetic material. Usually the organism (e.g. a bacterium) is provided with a new trait that is identifiable after transformation.

In this lab we transformed a strain of E. coli with the plasmid (a piece of circular DNA) pGLO containing the genes Beta Lactamase (ampicilin [an antibiotic] resistance) and Green Fluorescent Protein (GFP), a protein naturally found in the bioluminescent medusa ("jellyfish") Aequorea victoria.

The plasmid is forced into the bacteria through heat shock (42º C - 50 sec). The bacteria will take the plasmid, which contains several genes, including the ones of interest, and it will express them. In the presence of the sugar arabinose (in the culture medium) the GFP will be turned on and expressed, causing the bacteria to glow under UV light.

A couple of useful pics:

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Structure and function of nucleic acids

Today we covered pages 195-201 of the book. The chapter starts with DNA structure and function, although we threw in a little bit of RNA structure and function as well. The videos about transcrption and translation didn't work in the presentation I had in class, but I'll post them in this blog shortly.

Next reading: Chromosomes - pages 202-219 and 233-245

Quiz #5 Q&As

1. What are the three main steps of PCR?
Denaturation, annealing, extension (a.k.a. elongation)

2. What are the building blocks of DNA?
Sugar, phosphate group, nitrogenous base

3. What is transcription?
Trnasfer of information from DNA to RNA

4. What is gene duplication?
The copying of a gene and accidental retention of the copy within the genome. The two copies are functional, but one of them may mutate and become a pseudogene and/or eventually become a new functional gene.

5. What is a gene family?
A group of genes that have been generated throufh several gene duplication events, and therefore are similar to eac other in sequence and probably in function.

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The protein synthesis hippie dance

Internet is a great thing and it has interesting sites like Youtube... you can find ANY thing in Youtube. Inspired by the 'PCR song' video, another one of your classmates found this...

What did people do before computer animation existed? They danced. How did people illustrate in a [allegedly] fun way protein synthesis? Well... they got a guy more boring than Professor Frink (from The Simpsons) to explain protein synthesis with a blackboard in 3 minutes and then introduce 'the protein synthesis dance' as performed by a bunch of early 70's hippies (who seemed pulled out from the set of Jesus Christ Superstar) while moving to Iron Butterfly-like music (ask your parents or google it). The image is not that clear, but it sure is amusing...!



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Literature review paper topics

I have met with most of you and assigned topics for the literature review papers. You are allowed to change topics at any point in time before submitting the first draft (Oct 20th). So far here are the teams and topics:

• DNA fringerprinting disaster victims (Anessa and Chloé)
• Pre-natal genetic manipulation (Amy and Ryan)
• Recombinant DNA technologies in forensic sciences (Jonathan and Katie E.)
• Edible vaccines (Eric and Josh H.)
• Custom drugs (Amanda and Jackie T.)
• Gene therapy (Kyle and Courtney)
• Plant GMOs (Matt and Stuart)
• Evolution of MRSA (CJ and Katie S.)
• Plant disease resistance (Jackie C. and Josh J.)
• The use of DNA in finding missing people (David and Mike)
• The use of DNA in releasing innocent prisoners (John and Brandon)
• Effects and detection of DiGeorge Syndrome (22q11.2 deletion syndrome)(Krystal and Phil)
  

Here are some of the other topics that most students came up with. Any team is free to pick any of the following topics if unsatisfied with the topic of choice. Again: as long as it is BEFORE submitting the fisrt draft.

• Genetic predisposition to disease
• The role of molecular biology in biofuels research
• Pre-natal genetic screening
• Drug resistance in crops
• Disease diagnosis with molecular tools
  

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Contribution from a class mate - The PCR song

I knew about this but I had forgotten about it. One of your class mates found it and wanted to share it with you, so here it goes...

They are nerds, and they obviously grew up in the 80's... oh, and it's a Bio-Rad ad, in case you haven't have enough of them with our lab kits... The PCR song.



The lyrics are actually a good simple review of PCR

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Genomes and diversity - conclusion

Today we finished the introductory topic of the class, in which we talked about mechanisms of generation of new genes, with some emphasis on gene duplication and horizontal gene transfer.

After class there were some doubts about paralogy and orthology, so make sure you understand the difference, or voice your questions in class tomorrow. The difference is simple, but its understanding very important. In case I didn't make my self clear, here's the one line version of the difference: Ortholog genes were separated by a speciation event. Paralog genes were separated by a gene duplication event. It is possible that there is a gene duplication event, and then a speciation event. The two new species will inherit BOTH copies of the gene. Copies 1 and 1 will be orthologous, as well as copies 2 and 2. But copies 1 and 2 will be paralogous within AND among species. Any questions? Please ask in class. No reason to be shy! (It will wake you up. If sleepy BRING COFFEE!)

Reading for Tuesday Sep 30th: Still chapter 4, pages 195-201.


Quiz #4 Q&As

1. Write 4 questions for the next quiz.
Answers will vary

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