Scientists have long believed that the genes of bacteria can be integrated into the genetic code of animals, which is known as horizontal gene transfer, and has been used to explain the origin of certain genes present in animal DNA. However, no direct evidence was received to confirm this theory.
Now, however, researchers at the University of Tokyo have found that some genes of the Wolbachia bacteria have been integrated into the DNA of the Callosobruchus chinensis cockroach. This bacterium is the parasite of the cockroach and other insects that inhabit within their cells. However, by checking that the cockroaches contaminated by the bacteria were not cured with antibiotics, the researchers suspected that a gene transfer had occurred. Thus, the DNA of the cockroach was analyzed and about 11 genes of the bacteria were found on their chromosome.
This result allows to know if something similar happened in humans and if the genes of genetically modified foods can pass to the bacteria that inhabit the intestine.