Complex sentence: In addition to homologous recombination, transcriptional regulation also plays an important role in antigen switching, in contrast to other pathogens where antigenic variation is typically mediated by DNA rearrangements or transcriptional regulation.
Split into simpler sentences: In addition to homologous recombination, transcriptional regulation also plays an important role in antigen switching. This is in contrast to other pathogens where antigenic variation is typically mediated by DNA rearrangements or transcriptional regulation.