Assembly of actin I in S. lemnae therefore requires at least six events of conventional DNA deletion (joining segments 3 8 and 1 2), plus insertion of segment 9 between segments 8 and 10 and inversion of segments 1 and 2, as well as their translocation to the 5' end of the molecule (or inversion of segments 3 10) (see Results section on DNA Permutation for more details).
Assembly of a functional S. lemnae actin I macronuclear gene requires inversion of segments 1 and 2, coupled with translocation to the 5' end (or inversion of segments 3 10), plus insertion of segment 9 between 8 and 10, yielding two possible pathways for the permutation events during actin I descrambling (Figure 4).
In viperid toxin genes, however, the insertions of segments do not occur at the intron-exon boundaries, so the mechanism of insertions/deletions or switching of segments does not occur due to errors in splicing.
Among such genomes, typically the gene orders are partially conserved, and this information can be used to identify genuine orthologs (except in the case where HGT is included by homologous recombination or independent insertions of segments carrying the same set of genes at orthologous loci in different genomes; see the Discussion section).
Larger lamellar spacing in N6I/T blends is due not to the insertion of N6I/T segments into the interlamellar regions but to an increase in the lamellar thickness.
In contrast, some bands were larger than the expected size, suggesting insertion of DNA segments at these loci (Additional file 2).
In the long chain 3FTxs only, the insertion of a segment occurs at the intron-exon boundary due to a shift in the splicing site (discussed above).
This would be expected if resistance were conferred by the insertion of a segment of DNA, which contains the SNPs that failed to amplify, and is absent from susceptible individuals [ 51].
Mutations result from unrepaired damage to DNA that occurs due to errors in the process of replication or from the insertion or deletion of segments of DNA by exogenous agents.
The remaining primate-specific breakpoints may be attributable to chromosome fusions and insertions of small segments.
