(iii) Chromosome fusions or fissions may have produced most interchromosomal rearrangements, as suggested by the proportion of interchromosomal breakpoints containing centromeric and telomeric satellites (present study) and by early cytogenetic analyses [ 44].
The map expansion results (Table 5 and Figure 3) indicate the accumulation of recombination events over generations, which can be valuable for study design: If an investigator intervenes at an intermediate generation to speed up the process toward inbreeding, what proportion of the final recombination breakpoints might be lost, and so to what extent might mapping precision be eroded?
Breakpoints in the patterns of activity were found by performing piecewise linear regressions for proportion of flight time versus date; breakpoints (number and positions) were determined by the bootstrap restarting algorithm implemented in the segmented R library [ 14].
The proportion of laboratories using the M100-S12 breakpoints for ceftriaxone and cefotaxime increased an average of 3% per month from January 2002 to June 2003.
Table 1 shows the average breakpoint locations from 100 replicates and Table 2 shows the proportion of times we recover a breakpoint at approximately the correct location (within 50 bp) and the average Robinson-Foulds distance between the inferred and true trees.
The lower proportion of CNVs showing insertions at the breakpoint in the present study may be due to the initial selection criteria which excluded larger deletions 6 of the 9 such insertions in the previous study were associated with deletions larger than 5707 bp (the largest of the 20 deletions in the present study).
This observed number was then tested against a null model of random breakpoints across the genome, by a binomial test where the probability of a single breakpoint being contained in a gene is the proportion of the genome covered by genes, and the number of trials in the test is the number of breakpoints in total.
If looking at instability as the proportion of each chromosome that is altered the pattern of instability is very different from that derived from the number of breakpoints per chromosome.
By means of a simulation with 100,000 iterations, we then estimated the proportion of the genome in which these 519 breakpoints would have been expected to occur, by chance alone, given a certain specified number of genomic regions available to harbour evolutionary breakpoints (Additional file 6).
The results identify breakpoints in 1p1 as associated with early mortality when they occur in linksets of breakpoints in 1p3 and any one of 11q1, 11q2, or 6q2.
