Cockroaches scurry around with thousands of pieces of bacterial genomes

Cockroaches incorporate significant amounts of bacterial DNA into their own genomes, a phenomenon known as horizontal gene transfer, according to a study published this week. This research builds upon a previous study that highlighted the prevalence of horizontal gene transfer in the origin of complex cells, demonstrating that genomes can be assembled from genetic material from multiple species. While horizontal gene transfer is understood to be common among microbes due to their environments and cellular structures, the new study reveals its surprising frequency in multicellular animals. By analyzing the genomes of several cockroach species, scientists found evidence that these insects have retained fragments of bacterial DNA for millions of years. This discovery suggests that the evolutionary history of even complex organisms may involve more intricate connections than previously understood, with genetic threads linking distant branches of the tree of life.