Cats are the only animals in which the parasite Toxoplasma gondii can reproduce and form cysts, which are then shed in their feces. In the environment, these cysts contaminate water, soil, and food, and can infect other animals and humans. Although this parasite has been studied for decades, a major challenge has been that its sexual reproduction only occurs in the feline intestine, making this stage difficult to access and understand.
Now, the Uruguayan team — composed entirely of women: Saira Cancela, Florencia Sena, Romina Pagotto, Martina Crispo, María Eugenia Francia, and Mariela Bollati-Fogolín — has managed to recreate those conditions outside the feline host using a “mini-intestine,” a miniature version of the organ grown in the lab from cells. This tool not only makes it possible to study biological processes outside a living organism, but also reduces the need for experimental animals.
“This development represents years of collaborative work among three institute laboratories*, in which we were able to recreate a previously almost inaccessible process of the parasite. Doing so required combining knowledge of cell biology, metabolism, and parasite genetics,” explained Cancela and Sena, the study’s lead authors.
The scientists also succeeded in mimicking the feline intestinal environment and manipulating a gene called MORC, which regulates the onset of the parasite’s reproductive stage — meaning they were able to induce and observe sexual reproduction in the lab.
“Until recently, the role of MORC proteins in T. gondii was a mystery. Today we know that they act as key epigenetic regulators in the transition toward the sexual stages,” they added.
This breakthrough provides the world’s first tool to study this stage of the parasite in the laboratory and opens new pathways to understand how toxoplasmosis is transmitted and how the parasite evolves.
Full article available here.
* The work involved the Cellular Biology Unit, the Apicomplexan Biology Laboratory, and the Laboratory Animal Biotechnology Unit at the Institut Pasteur de Montevideo — all led by women.
