Direct Visualization of Horizontal Gene Transfer
Nature's little bytecode manipulation framework caught red-handed! You want to read lines D and E (which are the same in different colors) from left to right. In each picture, at the bottom you have the "source"strand, top left you have the scaffolding (2 strands: F Pilus), and in the middle going to the upper right you have the "weaved DNA" (1 strand and then 2 strands). The fluorescent green dots show the replicated code.
Conjugation allows bacteria to acquire genes for antibiotic resistance, novel virulence attributes, and alternative metabolic pathways. Using a fluorescent protein fusion, SeqA-YFP, we have visualized this process in real time and in single cells of Escherichia coli. We found that the F pilus mediates DNA transfer at considerable cell-to-cell distances. Integration of transferred DNA by recombination occurred in up to 96% of recipients; in the remaining cells, the transferred DNA was fully degraded by the RecBCD helicase/nuclease. The acquired integrated DNA was tracked through
successive replication rounds and was found to occasionally split and segregate with different chromosomes, leading to the inheritance of different gene clusters within the cell lineage. The incidence of DNA splitting corresponds to about one crossover per cell generation.
For my software friends. Cross cutting concerns in nature are transmitted horizontally, rather that vertically through inheritance. This of course lends flexibility and speed of adaptation to the species and it only makes sense that such a mechanism would have evolve. Those who have it will be more nimble and good features get propagated real quick across a population.