The probability density is based on the experimental finding that MTs in vitro undergo a three-step aging process leading to catastrophe, resulting in catastrophe lengths (l c ) that follow a Gamma distribution (Gardner et al., 2011).
At this increased mutation rate the RNA virus becomes randomised, and loses all information – it has entered the region of 'error catastrophe' which is the length beyond the Eigen limit.
As in all his work, Shawn suggests mankind is heading towards catastrophe; but, even at this inordinate length, he does so with mordant humour.
My whole point is that there were specific reasons for it being a trying time, not least Koonin's own 'intron catastrophe', which I discuss at some length later in the paper.
Thus, both kinesins are catastrophe factors; Kip3 mediates fine control of microtubule length by narrowing the distribution of maximum lengths prior to catastrophe, whereas MCAK promotes rapid restructuring of the microtubule cytoskeleton by making catastrophe a first-order random process.
GF (15 μM) increased the length based rescue and the catastrophe frequencies (events/μm) by 83 and 175%, respectively compared to the control microtubules.
Their stochastic simulations give rise to exponentially distributed lengths and thus lifetimes, describing catastrophe as a single-step process rather than a multistep one.
Thus, an enhanced mutability via reduced Nmax is suggested as a good candidate proxy to increasing polymer length in the context of an error catastrophe.
That is, relatively frequent catastrophes occurred during which they lost relatively little polymer length as a result of the slowed shortening rates.
Each seeding point nucleates a MT polymer that grows until it either hits a boundary or reaches a target length imposed by the aging of MTs before catastrophe (Gardner et al., 2011) ('Materials and methods' MT growth).
And so they should be, since each work (varying in length from 12 seconds to 25 minutes) describes a sudden catastrophe.
