Gains and losses of deoxyribonucelic acid (DNA) cause copy number alterations that lead to loss of cell cycle regulators (Morgan et al., 2012).
Additionally, unequal crossover events often cause copy number variation (CNV) of the gene (Heim and Meyer 1992; Panserat et al. 1995; Steen et al. 1995; Løvlie et al. 1996; Gaedigk et al. 2010).
The recovery of a ∼80 kb transposition that through crossover recombination leads to duplications and deletions in the offspring underlines the potential of meiosis to not only create new allele combinations but also to cause copy-number alterations of transposed sequences.
While this in principle could cause copy number variation among interLIMPs, by circularization and loss of the intervening sequence, we saw no correlation between the position of the main recombination events and the changes in sequence coverage along the genome (Fig 4).
Return to the idea of "selfish genes" described above: what ultimately increases an allele's representation in the gene pool is its having some phenotypic effect that causes copies of that allele to be in more organisms in succeeding generations.
Unequal crossover is a recombination event between misaligned non-allelic sequences on a pair of homologous chromosomes and usually causes copy-number fluctuation by deletion or duplication of the gene region [ 29].
This reversibility causes copy-number variants to come to a steady-state frequency in nonselective conditions when a balance is attained between high rates of formation and loss (Reams et al. 2010).
These rearrangements cause these copies to have unusually long TIRs.
Strand invasion events occurring at the matching repeat on the sister chromatid preserves copy number while those occurring at unmatched repeats cause rDNA copy number changes.
The Guardian's Peter Bradshaw wrote of Santorum's earlier effort: "A real Christmas miracle would cause every copy of this film to spontaneously burst into flames".
