Evolution connection: Mitochondria and Plastids
Learning goals:
Students will understand that 1) mitochondria and plastids evolved through
endosymbiosis, and 2) this evolutionary history helps us make sense of the
characteristics of these organelles.
For the instructor:
This short slide set explains endosymbiosis. To integrate it best, use these slides
immediately after you’ve discussed plant and animal cellular organelles. Slides 7 and
14 could be cut to save time.
Each of the following slides comes with a sample script for the instructor. To review
this script, download the PowerPoint file and view the Notes associated with each slide.
Evolution connection: Mitochondria and Plastids
What is unique about the structure of mitochondria and
chloroplasts?
• double membrane
Evolution connection: Mitochondria and Plastids
What is unique about the structure of mitochondria and
chloroplasts?
• double membrane
• their own DNA
Photo from Christian Kukat, Christian A. Wurm, Henrik Spåhr, Maria Falkenberg, Nils-Göran Larsson,
and Stefan Jakobs. Super-resolution microscopy reveals that mammalian mitochondrial nucleoids
have a uniform size and frequently contain a single copy of mtDNA. PNAS 2011 108 (33) 1353413539
Evolution connection: Mitochondria and Plastids
What is unique about the structure of mitochondria and
chloroplasts?
• double membrane
• their own CIRCULAR DNA
circular
chloroplast
chromosome
linear
mammalian
chromosome
Evolution connection: Mitochondria and Plastids
What is unique about the structure of mitochondria and
chloroplasts?
• double membrane
• their own circular DNA
• their own ribosomes
Image from Sukhjit Kaur, Reynald Gillet, Wen Li, Richard Gursky, and Joachim Frank. Cryo-EM
visualization of transfer messenger RNA with two SmpBs in a stalled ribosome PNAS 2006 103 (44)
16484-16489.
Evolution connection: Mitochondria and Plastids
What is unique about the structure of mitochondria and
chloroplasts?
• double membrane
• their own circular DNA
• their own ribosomes
• multiply by binary fission
Mitochondria image © Rockefeller University Press, 1970; originally published in the Journal of Cell
Biology 47:373-383. Chloroplast image from Shin-ya Miyagishima. Mechanism of Plastid Division:
From a Bacterium to an Organelle. Plant Physiol. 2011 155: 1533-1544.
Evolution connection: Mitochondria and Plastids
What is unique about the structure of mitochondria and
chloroplasts?
• double membrane
• their own circular DNA
• their own ribosomes
• multiply by binary fission
Evolution connection: Mitochondria and Plastids
Why are mitochondria and chloroplasts so weird?
• double membrane
• their own circular DNA
• their own ribosomes
• multiply by binary fission
Evolution connection: Mitochondria and Plastids
Why are mitochondria and chloroplasts so weird?
Because of their evolutionary history! Both evolved via
endosymbiosis.
Evolution connection: Mitochondria and Plastids
Endosymbiosis in a series
1.
Evolution connection: Mitochondria and Plastids
Endosymbiosis in a series
1.
Evolution connection: Mitochondria and Plastids
Endosymbiosis in a series
2.
Evolution connection: Mitochondria and Plastids
Endosymbiosis in a series
2.
Evolution connection: Mitochondria and Plastids
Endosymbiosis in a series
3.
dinoflagellate
euglenoid
Dinoflagellate photo by Minami Himemiya. Euglenoid photo by Rogelio Moreno.
References:
Bhattacharya, D., Yoon, H. S., and Hackett, J. D. (2004).
Photosynthetic eukaryotes unite: endosymbiosis connects the dots.
Bioessays. 26: 50-60.
Chat J., Chalak L., and Petit R. J. (1999). Strict paternal inheritance
of chloroplast DNA and maternal inheritance of mitochondrial DNA
in intraspecific crosses of kiwifruit. Theoretical & Applied Genetics.
99: 314-322.
Emelyanov, V. V. (2001). Rickettsiaceae, Rickettsia-like
endosymbionts, and the origin of mitochondria. Bioscience
Reports. 21: 1-17.
McFadden, G. I. (2001). Primary and secondary endosymbiosis and
the origin of plastids. Journal of Phycology. 37: 951-959.
Yoon, H. S., Hackett, J. D., Ciniglia, C., Pinto, G., and Bhattacharya,
D. (2004). A molecular timeline for the origin of photosynthetic
eukaryotes. Molecular Biology and Evolution. 21: 809-818