Mutant patterns were generated by setting the levels of production of the relevant TF to zero or, for Gli /–, by setting the binding affinity of Gli to zero.
Overall the frequency of any one of these mutant patterns is low and collectively account for about 7% of the total haplotypes detected in our study.
The priors were then updated with the posterior distributions obtained from this fit and then the WT and mutant patterns were used together as targets; this was used to speed up the search process (the total time to obtain the approximate posterior distributions was around 3 weeks running on a single GPU).
In the stronger armXM19 mutant, patterning was abolished, all cells had a similar shape, secreted a denticle, and the planar distribution of all markers was uniform around cell margins (Fig. 2 B-B"').
She has seen cases in which scientists have failed to realize that their genetic mutants — for instance, Arabidopsis mutants with altered branching patterns — are recapitulating naturally occurring plant forms found in other lineages.
Reactive oxygen species (ROS) have recently been proposed as candidate signalling molecules in acclimation because they can modulate gene expression when added to cell culture media, and gene expression patterns are altered in mutants accumulating higher or lower levels of ROS [ 36- 38].
It may be important that the mutant pattern strength is revealed not as an elimination of errors, but rather primarily as a resistance to disruption by errors.
In the weaker armF1a mutant, some patterning was maintained, and cell shape changes were only mildly disrupted (Fig. 2 D-D"').
A mutant expression pattern is then associated with a lost CNS or a cluster of CNSs, and these previously mysterious sequences acquire a testable hypothesis as to ancestral function.
At early stages of ear development in the lau mutant, otic patterning was normal (supplementary material Fig. S1), and sensory patches and otoliths developed correctly (Whitfield et al., 1996) (and data not shown).
