Lecture 11 Trxn in Organelles

Lecture 11 Trxn in Organelles - T RANSCRIPTION IN O...

Info icon This preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon
TRANSCRIPTION IN ORGANELLES 1 Sunday, October 2, 2011
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
LAST TIME Regulated transcription during sporulation in B. subtilis Heat shock response in E. coli Acclimation to high light in cyanobacteria Circadian regulation of global transcription in cyanobacteria 2 Sunday, October 2, 2011
Image of page 2
TRANSCRIPTION IN ORGANELLES Mitochondria and Chloroplasts Types of RNA polymerases Composition of RNA polymerases Some evolutionary perspectives 3 Sunday, October 2, 2011
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Learning Outcomes 1. Discuss and apply the experimental design illustrating that cyanobacteria is under circadian control (from Lecture 10) 2. Describe the Endosymbiotic Theory and provide evidence based on molecular characteristics of plastids and mitochondria 3. Describe the features of RNAPs in mt and plastids including: enzymology (features of RNAP subunits) and evolution (current thinking on how the RNAPs evolved). 4. Provide a hypothesis as to why plastids have two functional RNAPs. By the end of this lecture, you should be able to: 4 Sunday, October 2, 2011
Image of page 4
CIRCADIAN RHYTHMS Oscillate with a period of ~24 hours Phase determined by light-dark cycle Once entrained, continue in “constant conditions” http://www.eb.tuebingen.mpg.de/research-groups/nick-foulkes/fish.jpg 5 Sunday, October 2, 2011
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
A Circadian System (aka Gene expression!) 6 Sunday, October 2, 2011
Image of page 6
Do circadian clocks exist in bacteria? What tools can we use to figure this out? 7 Sunday, October 2, 2011
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Q1: Are single celled organisms capable of circadian rhythms? A: Yes, we know that single celled organisms bioluminescence according to circadian rhythms. This dinoflagellate fluoresces at night. Gonyaulax polyedra Source: Physiologia Plantarum (1996) 96 (4):727-732 8 Sunday, October 2, 2011
Image of page 8
Vibrio harveyi Q2: Can bacteria cells bioluminesce? A: Yes, this gram negative bacteria will fluoresce in response to quorum sensing by expressing the luxAB operon, forming protein called luciferase ‘milky seas effect’ 9 Sunday, October 2, 2011
Image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Experimental Question: Do bacteria cells have a circadian clock? PpsbAI - promoter for psbAI gene (a p’syn gene) luxA + luxB = Vibrio luciferase gene Method: Engineer bioluminescence in Cyanobacteria by using luciferase genes from Vibrio. Bioluminescence becomes a way to detect circadian rhythms if they exist. 10 Sunday, October 2, 2011
Image of page 10
Hours in continuous light Detection of lux driven by photosynthesis gene promoter 11 Sunday, October 2, 2011
Image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
As time glows by in bacteria Carl Hirschie Johnson Populations of cells can exhibit remarkably precise and stable circadian oscillations. But can single cells achieve such precision in the absence of intercellular communication? For cyanobacteria, it seems so.
Image of page 12
Image of page 13
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern