Ed Yong provides a positive update on research findings that may save the use of cats in research laboratories.
Of the many parasites known to control the mind of their host, none is more famous than Toxoplasma gondii—the single-celled organism known colloquially as Toxo. It can survive in a variety of animals, but it only reproduces sexually in cats. If it gets into mice or rats, it alters their behavior so they become fatally attracted to the scent of feline urine. They get eaten, the cat gets infected and Toxo gets to make more Toxo.
Research has been cat-dependant because Toxo has sex only in cats because it depends on linoleic acid. Cats are the only mammals that build up enough of it. Other mammals deplete linoleic acid with an enzyme. Laura Knolls’ research team at the University of Wisconsin-Madison discovered a method to shut down the enzyme in mice. Now they’ve been successful at reproducing Toxo in mice.
Source: The Atlantic, July 11, 2019. Link. Knoll’s success would greatly accelerate the pace of Toxo research, because scientists could study the parasite using a common lab animal that’s more familiar and easier to work with.
INSIGHTS: Toxoplasma gondii is zoonotic, infecting more than a third of the world’s people, It is spread through undercooked meat, food or water contaminated by infected cat waste. While mostly harmless in humans, it can pass from mother to fetus, causing blindness, developmental problems, hydrocephalus, and other disabilities.
There is no vaccine or cure, and research has been generally slow and difficult, which Toxo’s cat-dependent life cycle doesn’t help.