MarSU scientists made a discovery in the field of parasitology
A group of biologists from the Mari State University, Penza State University, the Institute of Ecology and Evolution of the Russian Academy of Sciences, the Institute of Cytology of the Russian Academy of Sciences, the Privolzhskaya Forest-Steppe State Reserve and the National Museum of Natural History in Paris have experimentally discovered that polydactyly and complex deformities of the limbs that are incompatible with life are induced by exposure to the species trematode Strigea robusta. This is one of the first experimentally confirmed cases in Eurasia of limb deformation in amphibians under the influence of trematodes.
Earlier cases of induction of deformities by trematodes were noted in the United States: it was found that the trematode Ribeiroia ondatrae induces the development of additional limbs in tadpoles. The discovery explained many cases of morphological deformations over a vast territory in the United States. In Eurasia, an equal number of morphological deviations in amphibians are observed, but the causes of them are often unknown.
The research team was able to establish that morphological anomalies known as "P anomaly" and discovered for the first time in France in 1949 and 1952. by the famous biologist and writer Jean Rostand, are caused by the fluke Strigea robusta. Induction of anomalies occurs at the stage of metacercariae and leads to an increase in the fingers with lighter variants of anomaly, as well as, in severe cases, to shortening of the limbs, their inversion, the appearance of additional distal parts of the limbs, bone outgrowths, edema and neoplasms. Anomalies often lead to reduced mobility of tadpoles and young frogs, making them easier prey for their final hosts, which are waterfowl. The discovery explains the many cases of polydactyly in green frogs in Europe and Asia, as well as the severe cases of Jean Rostand's “P anomaly” that have repeatedly caused public alarm. The study is published in the leading parasitological journal BMC Parasites & Vectors (Q1).