A puzzling modification of DNA that’s frequent in microorganisms just isn’t current in people or different mammals. The research exhibits that detection of the epigenetic mark 6mdA in animals was most likely the result of limitations of the expertise used and bacterial contamination of samples.
A number of years in the past, some research had been printed that aroused appreciable curiosity amongst researchers in genetics. This research had examined a specific epigenetic mark or modification of the DNA that influences how the DNA sequence is utilized in totally different cells. This mark had not beforehand been noticed in multicellular organisms. The mark, often called “6mdA,” is, in distinction, frequent in bacteria, the place it performs an essential position in defending the bacteria towards viruses. One in all these involved the degrees of 6mdA detected, which have been so low that scientists puzzled whether or not such an uncommon epigenetic sign may really have a perform. Following these preliminary studies, another revealed research has been unable to detect 6mdA in animals.
Simply as many different analysis teams, Colm Nestor’s group at Linköping College began to review this puzzling epigenetic sign. They have been, nonetheless, unable to detect it in human or mouse cells. Eventually, they detected 6mdA in two samples of human cells; nevertheless, it turned out that each of the samples has been contaminated with mycoplasma microorganism. The researchers suspected that the epigenetic mark got here from the microorganism and never the human cells. They handled the cells with antibiotics in opposition to mycoplasma and noticed the 6mdA sign disappear.
The actual pressure of mycoplasma they discovered is frequent in wholesome individuals and sometimes doesn’t trigger any adverse health results. Since mycoplasma microorganism can exist not solely outdoors cells but in addition inside cells within the physique, it could be that this bacterium is current, however undetected, in human samples. For many forms of microorganism, researchers can simply detect if cells cultured within the laboratory are contaminated. Nonetheless, this isn’t the case for mycoplasma contamination, which requires particular testing.
The LiU researchers quickly found that it isn’t solely mycoplasma micro organism that triggers issues for researchers finding out the 6mdA mark. They also discovered issues with a number of strategies used to detect this epigenetic modification.