APPENDIX 1: HOW TO WRITE UP AN EXPERIMENT IN YOUR LABORATORY NOTEBOOK Example: CILIAR REGENERATION IN Tetrahymena pyriformis. INTRODUCTION. Several ciliated and flagellated cell types have the ability to regenerate their cilia if the cilia are gently removed. Therefore these cells have been used to study factors which can influence ciliary growth. It has been found that regeneration depends upon processes which promote assembly of ciliary tubulin subunits into microtubules and not on protein synthesis following deciliation. Polymerization of microtubules requires exchange of tubulin dimers between the growing microtubule and a cytoplasmic dimer pool. The tubulin monomers are constituitively synthesized by the cell and tubulin heterodimers are assembled in the cytoplasm. The dimers then add at the growing (+) end of elongating microtubules which are located at the tips of regenerating cilia. Various drugs are known to alter the microtubule assembly process. Some act by inhibiting or enhancing tubulin polymerization, while others block tubulin synthesis. The experimental cells used in this exercise will be those of the ciliate protozoan This organism had been widely used in cell physiology research. In Tetrahymena pyriformis. nature Tetrahymena feed on bacteria; but in the laboratory, they can be grown on a variety of nutrient media in axenic culture (i.e., without other organisms). Historically Tetrahymena was the first eukaryotic cell to be cultured in a completely defined medium. It was also the first cell to be artificially synchronized with respect to cell division. has a very Tetrahymena short generation time, dividing every three to four hours under favorable conditions; hence, large numbers of cells can be grown in a short time. LIVE/DEAD Cell Viability In this procedure, living cells are distinguished from dead cells based upon the integrity of the cell membrane. Dead cells are penetrated by water soluble compounds that cannot cross intact plasma membrane and dead cells lose their cytosolic components by diffusion through the compromised membrane. We will use the membrane exclusionary dye, trypan blue, to assess cell viability.
APPENDIX 1: HOW TO WRITE UP AN EXPERIMENT IN YOUR LABORATORY NOTEBOOK Example: CILIAR REGENERATION IN Tetrahymena pyriformis. INTRODUCTION. Several ciliated and flagellated cell types have the ability to regenerate their cilia if the cilia are gently removed. Therefore these cells have been used to study factors which can influence ciliary growth. It has been found that regeneration depends upon processes which promote assembly of ciliary tubulin subunits into microtubules and not on protein synthesis following deciliation. Polymerization of microtubules requires exchange of tubulin dimers between the growing microtubule and a cytoplasmic dimer pool. The tubulin monomers are constituitively synthesized by the cell and tubulin heterodimers are assembled in the cytoplasm. The dimers then add at the growing (+) end of elongating microtubules which are located at the tips of regenerating cilia. Various drugs are known to alter the microtubule assembly process. Some act by inhibiting or enhancing tubulin polymerization, while others block tubulin synthesis. The experimental cells used in this exercise will be those of the ciliate protozoan Tetrahymena pyriformis. This organism had been widely used in cell physiology research. In nature Tetrahymena feed on bacteria; but in the laboratory, they can be grown on a variety of nutrient media in axenic culture (i.e., without other organisms). Historically Tetrahymena was the first eukaryotic cell to be cultured in a completely defined medium. It was also the first cell to be artificially synchronized with respect to cell division. Tetrahymena has a very short generation time, dividing every three to four hours under favorable conditions; hence, large numbers of cells can be grown in a short time. LIVE/DEAD Cell Viability In this procedure, living cells are distinguished from dead cells based upon the integrity of the cell membrane. Dead cells are penetrated by water soluble compounds that cannot cross intact plasma membrane and dead cells lose their cytosolic components by diffusion through the compromised membrane. We will use the membrane exclusionary dye, trypan blue, to assess cell viability.
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