Polystoma gallieni: experimental evidence for chemical cues for developmental plasticity.
Among monogeneans that display direct life cycles, plastic developmental strategies may have been selected to counter the lack of transmission opportunities. Within amphibian polystomatids, some species of the genus Polystoma develop into two different phenotypes depending on the host physiological stage to which free swimming larvae attach. When oncomiracidia infest old tadpoles, they develop slowly and migrate during host metamorphosis towards the bladder where they reach maturity. On the other hand when larvae infest young tadpoles, they develop rapidly into neotenic phenotypes that reproduce in the branchial chamber. These alternative developments are explored through experimental infestations with Polystoma gallieni, the specific polystome of the stripeless tree frog Hyla meridionalis. When oncomiracidia were left for 6h in water in which young tadpoles had been previously maintained for one day, they mainly developed into the neotenic phenotype regardless of the tadpole stage they encountered later. This indicates that P. gallieni could collect released host-derived signals before physical contact with its host.
Badets
Mathieu
M
UMR 5244 CNRS-EPHE-UPVD, Biologie et Ecologie Tropicale et Méditerranéenne, Parasitologie Fonctionnelle et Evolutive, Université Via Domitia, Perpignan, France. mathieu.badets@univ-perp.fr
Boissier
Jérôme
J
Brémond
Philippe
P
Verneau
Olivier
O
D000818:Animals; D001001:Anura / Q000254:growth & development / Q000469:parasitology*; D005602:France; D005618:Fresh Water; D005880:Gills / Q000469:parasitology; D006790:Host-Parasite Interactions; D007814:Larva / Q000254:growth & development / Q000469:parasitology; D010641:Phenotype; D010986:Platyhelminths / Q000254:growth & development*; D014201:Trematode Infections / Q000469:parasitology / Q000503:physiopathology / Q000662:veterinary*; D001743:Urinary Bladder / Q000469:parasitology