The problem of viability estimates in tests for reverse mutations.

These systems can check for forward and reverse mutations, as well as recombinant events.

Reverse mutations occur which change the mutated sequence back to the original wild type sequence.

When news of a "cure" that would reverse mutations suddenly arises, Beast finds himself seriously considering taking it so he can once again appear human.

Reverse mutation - The mutation can revert to normal or to a premutation carrier state.

Reverse mutation is the only exception to the general rule that a trait created by mutation has not appeared in an ancestor.

There are still occasional reverse mutations eliminating the melanin adaptation, which would be useful for the moths were English industrial pollution to be controlled.

Escherichia coli systems - Both forward and reverse mutation detection system have been modified for use in E. coli.

As with the traditional Ames test, the sample is compared to the natural background rate of reverse mutation in order to establish the genotoxicity of a substance.

Tryptophan-deficient mutant is used for the reverse mutation, while galactose utility or resistance to 5-methyltryptophan may be used for forward mutation.

The Bacterial Reverse Mutation Assay, also known as the Ames Assay, is used in laboratories to test for gene mutation.

A third form of repair is revertant mosaicism, which is naturally occurring by creating a reverse mutation or a mutation at a second site that corrects the reading frame.

Genetic saturation is the reduced appearance, which occurs over time, of sequence divergence rate that results from reverse mutations, homoplasies and other multiple changes occurring at single sites along two lineages.

A transposable element (TE) is a DNA sequence that can change its position within the genome, sometimes creating or reversing mutations and altering the cell's genome size.

Resistance to 8-azaguanine in S. typhimurium - Similar to Ames test, but instead of reverse mutation, it checks for forward mutation that confer resistance to 8-Azaguanine in a histidine revertant strain.

The next step (4 in Fig. 3) was to reverse mutations in the nuclear localization signal (NLS) that is required to import the transposase enzyme from the cytoplasm where it is made to the nucleus where it acts.

The 96-well plates are incubated for up to five days, with mutated (yellow) colonies being counted each day and compared to the background rate of reverse mutation using established tables of significance to determine the significant differences between the background rate of mutation and that for the tested samples.