By Levi Clancy for Student Reader on
|Length||# Per Cell||Motion|
|Flagella||Long; > 5µm||1-2/cell||Whiplike|
|Cilia||Short; <5µm||100s/cell||Breast stroke|
Axoneme (9+2 structure, MT bundle) is 9 pairs of microtubules around central pair. Microtubules are made of a- and B-tubulin). Surrounded by cell membrane. Dynein, ATP-dependent molecular motor, attached to tubulin. Whip-like motion. Cilia are structurally the same.
1) Isolate intact flagellum
2) Remove membrane with detergent
3) Left with flagellic cytoskeleton.
4) Flagella still moves (sliding filament model)
Mutagenize wildtype cells so they cannot move. You can find the tightest colonies, or you can put them in a solution and find which ones sink to the bottom. Isolate a mutant, grow it up, and then grow up the ones from the bottom yet again. Transfer bottoms to fresh flask, and if they are motility mutants then all should settle. You then study those under a microscope. The mot(-) cells sometimes had no, stubby or rigid flagella. The ones with rigid flagella lacked radial spokes, so those are required for flagellic motility.