title: Monohydrocalcite in calcareous corpuscles of Mesocestoides corti.
abstract: Mesocestoides corti (syn. vogae), as many other cestode platyhelminthes, contains abundant mineralized structures called calcareous corpuscles. These concretions may constitute as much as 40% of the dry weight of the organisms, but their function remains poorly understood. In this work, we reviewed the mineral composition of the calcareous corpuscles of M. corti. X-ray diffraction pattern showed that the major mineral component of the corpuscles is a hydrated form of calcium carbonate, monohydrocalcite, also confirmed by infrared spectrometry. The baseline shift of the X-ray diffraction spectra suggested the presence of amorphous calcium carbonate, accordingly to previous reports, and an organic matrix was confirmed by FTIR. Monohydrocalcite is a rare mineral unusually found in biominerals. Although the significance of monohydrocalcite in biominerals has not been determined, the knowledge of corpuscles composition is of relevance to establish their function and for the elucidation of the mechanisms involved in mineralization processes.
authors.affiliation: Sección Bioquímica, Facultad de Ciencias, Universidad de la República, Iguá 4225, CP 11400, Montevideo, Uruguay.
authors.forename: Mario
authors.initials: M
authors.lastname: Señorale-Pose
authors.forename: Cora
authors.initials: C
authors.lastname: Chalar
authors.forename: Yannicke
authors.initials: Y
authors.lastname: Dauphin
authors.forename: Pierre
authors.initials: P
authors.lastname: Massard
authors.forename: Philippe
authors.initials: P
authors.lastname: Pradel
authors.forename: Mónica
authors.initials: M
authors.lastname: Marín
mesh_terms: D000818:Animals; D002119:Calcium Carbonate / Q000032:analysis* / Q000737:chemistry; D008645:Mesocestoides / Q000737:chemistry* / Q000648:ultrastructure; D051379:Mice; D008855:Microscopy, Electron, Scanning; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D002119:Calcium Carbonate