Accounting for plating efficiency when estimating spontaneous mutation rates
1School of Medicine, Flinders University of South Australia, Adelaide.
Abstract:
When the spontaneous mutation rate mu in mammalian cell cultures is estimated using Luria-Delbrück fluctuation analysis, many factors contribute to the unreliability of the estimate. Some of these have been documented by Featherstone et al. (1987) and by Kendal and Frost (1988). In particular, the plating efficiencies for mammalian cells are often much less than 100%, and this can be taken into account. A derivation of a generalized P0 estimator, mg, based on the classical P0 estimator of Luria and Delbrück (1943) is offered. In an experiment involving C cultures, of which z exhibit no mutant colonies, and in which the plating efficiency is p, (0 < p < 1), the estimated mean number of mutations per culture is given by [formula: see text] The classical P0 estimator is shown to be the limiting case of mg as plating efficiency tends to 100%.
Insights
Estimating mammalian cell mutation rates using Luria-Delbrück analysis is unreliable. A new generalized P0 estimator (mg) accounts for low plating efficiencies, improving mutation rate accuracy.
Area of Science:
- Genetics
- Cell Biology
- Biostatistics
Background:
- Estimating spontaneous mutation rates (mu) in mammalian cell cultures via Luria-Delbrück fluctuation analysis is prone to unreliability.
- Factors influencing estimate accuracy include low plating efficiencies, which deviate from the classical analysis assumptions.
Purpose of the Study:
- To address the unreliability of spontaneous mutation rate estimation in mammalian cell cultures.
- To derive a generalized P0 estimator that incorporates variable plating efficiencies.
Main Methods:
- The study derives a generalized P0 estimator, denoted as mg.
- This estimator is based on the classical P0 estimator developed by Luria and Delbrück (1943).
- The derivation accounts for experiments with C cultures, where z exhibit no mutant colonies and plating efficiency is p (0 < p < 1).
Main Results:
- A formula for the generalized P0 estimator (mg) is presented: [formula].
- The classical P0 estimator is demonstrated to be a limiting case of mg when plating efficiency approaches 100%.
Conclusions:
- The generalized P0 estimator (mg) offers a more accurate method for estimating spontaneous mutation rates in mammalian cell cultures.
- This improved method is particularly valuable when dealing with plating efficiencies significantly less than 100%.
