@article {15497, title = {A new chronotype of Schistosoma mansoni: adaptive significance}, journal = {Tropical Medicice and International Health}, volume = {17}, number = {6}, year = {2012}, note = {Journal Article
Research Support, Non-U.S. Gov{\textquoteright}t
England
Tm \& ih}, month = {Jun}, pages = {727-32}, abstract = {OBJECTIVES: To optimise host-to-host transmission, digenean trematodes (parasites) synchronize their cercarial emission patterns with the aquatic activities of their vertebrate hosts. Schistosoma mansoni has a strictly diurnal shedding pattern involving two circadian chronotypes: an early shedding pattern with a mean peak occurring at 11:00 h and a late pattern with a mean peak occurring at 16:00 h. We analysed the cercarial emergence pattern of three schistosome populations from Oman where S. mansoni is resurgent. METHODS: For each schistosome population, the cercarial emergence pattern was assessed hourly over several days. Because we identified a new chronotype hitherto unknown in S. mansoni, we undertook taxonomic characterisation based on egg morphology and mitochondrial DNA sequence (COX1). RESULTS: Taxonomic characterisation revealed that the three schistosome populations belong to the species S. mansoni. Hence, this is the first report of this species exhibiting a nocturnal chronotype, with the mean peak occurring at 20:00 h. We interpreted the new chronotype as being the result of a lateral transfer of S. mansoni from humans to Rattus rattus. CONCLUSION: The cercarial emergence pattern of S. mansoni from Oman is circadian, exhibiting either a diurnal or a nocturnal phenotype.}, keywords = {*Circadian Rhythm, Animals, Oman, Phenotype, Schistosoma mansoni/*classification/*physiology, Species Specificity}, isbn = {1365-3156 (Electronic)
1360-2276 (Linking)}, author = {Mouahid, G. and Idris, M. A. and Verneau, O. and Th{\'e}ron, A. and Shaban, M. M. and Mon{\'e}, H.} }