Thorough Intro To SDM For Osley Lab (82109)


Published on

I made this presentation to show some collaborators whose lab I worked in last semester. In it I discuss the past, present, and future of Shotgun DNA Mapping and all that it contains.

Published in: Education, Technology
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Thorough Intro To SDM For Osley Lab (82109)

  1. 1. A Thorough Introduction to Shotgun DNA Mapping and Kicking Ass in Science<br />I made this…<br />Presents:<br />By Anthony<br />…and this<br />
  2. 2. Thank You Osley Lab<br />A big thanks to Kelly and Mary Ann… <br />Thanks Cory and Toyoko…<br />…and KochLab<br />
  3. 3. Motivation<br />Need better ways to study native chromatin<br />Single-molecule analysis can have a huge impact<br />Kornberg said so:<br />“By pulling at the DNA with forces strong enough to unwrap DNA from the histoneoctamer, the optical tweezer allows for counting the remaining nucleosomes at the end of the remodeling process.”<br />Reassembled Nucleosomes<br />RNA Pol II<br />promoter<br />cryptic<br />promoter<br />Transcription<br />
  4. 4. Shotgun DNA Mapping in a Nutshell<br />What this talk is mostly about<br />Austin is in there too<br />Procedure<br />Library of Simulated Curves<br />Random fragment<br />Experimental Force<br />Endonuclease<br />Genomic DNA<br />Correct Match<br />dsDNA anchor<br />Step 1: Digest genome into fragments<br />Step 2: Unzip fragment and record forces<br />Step 3: Compare experimental forces to a library of simulated curves<br />
  5. 5. How will it work on native chromatin?<br />Unzip with everything attached<br />Allow dsDNA to rezip by relaxing strand<br />Unzip naked DNA<br />Use matching program to locate strand and binding sites in genome<br />dsDNA<br />Bound protein etc.<br />
  6. 6. How Matching Works<br /><ul><li>Using known physical models you can predict (simulate) what the force profile of unzipped dsDNA would look like
  7. 7. You then can compare that to actual unzipping data
  8. 8. Correct matches yield match scores close to zero, just how Larry defined it</li></ul>A<br />B<br />Correct Match, Score 0.2<br />Mismatch, Score 0.8<br />18<br />18<br />Force (pN)<br />Force (pN)<br />12<br />12<br />0<br />1500<br />0<br />1500<br />Unzipping fork index (bp)<br />Unzipping fork index (bp)<br />
  9. 9. More about matching<br />When actual and simulated unzipping events are compared we can see one distinct match<br />Test of 32 tethers of same sequence of unzipped DNA worked every time!<br />
  10. 10. How do Tweezers Work?<br />We can measure forces on the bead based on deflections<br />observed by a QPD (quadrant photodiode).<br />
  11. 11. Our Optical Tweezers<br />movie of tweezer setup<br />
  12. 12. Where do you start?<br />Need genomic DNA from yeast<br />Grow some yeast<br />Extract the DNA<br />Now we’re Koching<br />A blurry image of yeast cells<br />
  13. 13. Yeast Cell<br />Spheroplasting<br />RNaseA-ing<br />Phenol/Chloroform Extraction and Ethanol Precipitation<br />It’s foreign so it’s gotta be evil<br />
  14. 14. Next Step<br />Need digested plasmid DNA and digested genomic DNA<br />Want to clone fragments<br />For sequencing<br />So we can unzip a lot of fragments<br />Michael Bay’s next film… too late I already sold the rights<br />
  15. 15. The first of many gels<br />Lanes:<br />1: pRS413 uncut<br />2: pRS cut with XhoI<br />3: pRS cut with NotI<br />4: pRS cut with BstXI<br />5: genomic uncut DNA (gDNA)<br />6: gDNA cut with XhoI<br /> (didn’t work)<br />10kb length<br />My archnemesis<br />
  16. 16. Digested gDNA<br />Lanes:<br />1: Uncut gDNA<br />2: gDNA cut with XhoI<br />3: gDNA cut with XhoI (for redundancy) <br />Get used to this, there is a lot more coming<br />Making this was really annoying<br />
  17. 17. Inserting DNA<br />CIP – Calf Intestinal Phosphatase<br />T4 DNA Ligase - ??? DNA Ligase<br />Terminators can’t self terminate.<br />
  18. 18. Making Clones<br />Mix Competent E. coli cells with plasmid DNA<br />E. coli readily replicates plasmid<br />Grow cells on petri dish<br />Cells grow into individual colonies<br />If plasmid has inserts then each colony is a separate insert<br />One of them likes pizza<br />
  19. 19. Transformation Success?<br />E. Coli DNA<br />Extracted plasmid DNA<br />This is all Koch’s fault<br />
  20. 20. Double Digest and pBluescript<br />I was drunk when I took this picture<br />I was drunk when I slept with this one<br />
  21. 21. Redoing with pBS<br />Now that is definitely some random genomic fragments<br />Top Image quick extraction<br />Bottom Image is good extraction<br />I like pink tape<br />
  22. 22. Sequencing<br />Involves some steps I don’t know<br />Need to sequence so that when we unzip we can know what the correct match is<br />Larry look away<br />Not for Larry’s Eyes<br />I thought it would be funny if I used a print screen of this slide for this slide.<br />
  23. 23. Tether Construction<br />Make an oligo that has BstXI site and is Biotinylated<br />We made 2:<br />One is a hairpin with a NotI site<br />The other is two single stranded oligos with a SapI site<br />Remember our fragments have both NotI ends and SapI ends<br />BstXI<br />pRL fragment<br />NotI<br />NotI hairpin<br />or<br />SapI<br />Top and bottom<br />Annealed oligos<br />NotI end<br />SapI end<br />The sequel to Michael Bay’s movie<br />Rights also already sold<br />
  24. 24. When it’s all done<br />More on next slide<br />gDNA<br />plasmid<br />Biotinylated fragment<br />Digitylated fragment<br />…<br />Gel of Digested Fragments<br />This is what skittles does to your DNA<br />The quality of this image is a direct result of a computer from 1991<br />
  25. 25. What I have now<br />What it should look like<br />What it looks like<br />both<br />fragment<br />anchor<br />1991 strikes again<br />2009 artist rendition<br />
  26. 26. Combine with Fragments<br />Ligate the plasmid random fragments to the tethering construct<br />Use flow chamber fluidics to prepare sample for tweezing<br />Tweeze<br />
  27. 27. The Future<br />Unzipping Nucleosomes<br />Unzipping RNA Pol II from two directions<br />Hope is that it will provide different unzipping signatures<br />
  28. 28. No Mas<br />