Trichinella spiralis larvae within muscle, Wikimedia, Froggerlaura Bucking the trend among DNA methylators, whose epigenetic marks on the genome tend to be stable over their lifetimes, the parasite Trichinella spiralis accumulates methyl tags over time, according to a study published in Genome Biology last week (October 17). It is also the first nematode found to carry a methylated genome.
“I was actually very surprised, not only because we indeed found DNA methylation in the T. spiralis genome, but also T. spiralis seems to be the only nematode that uses DNA methylation among the eleven nematodes we analyzed,” senior author Liu Mingyuan, a zoonosis researcher at Jilin University, China, wrote to The Scientist in an email. And, he added, it “seems to use DNA methylation in a drastic way.”
During its lifecycle, T. spiralis infects muscle tissue of various mammals, and people can become infected by eating uncooked contaminated meat. Once the parasites arrive in the small intestines, larvae mature into adults and mate. The resulting newborn worms wiggle into the bloodstream, nestle into muscle tissue, and encyst, staying dormant until they’re roused back through ...