title: Heme crystallization in the midgut of triatomine insects.
abstract: Hemozoin (Hz) is a heme crystal produced by several blood-feeding organisms in order to detoxify free heme released upon hemoglobin (Hb) digestion. Here we show that heme crystallization also occurs in three species of triatomine insects. Ultraviolet-visible and infrared light absorption spectra of insoluble pigments isolated from the midgut of three triatomine species Triatoma infestans, Dipetalogaster maximus and Panstrongylus megistus indicated that all produce Hz. Morphological analysis of T. infestans and D. maximus midguts revealed the close association of Hz crystals to perimicrovillar membranes and also as multicrystalline assemblies, forming nearly spherical structures. Heme crystallization was promoted by isolated perimicrovillar membranes from all three species of triatomine bugs in vitro in heat-sensitive reactions. In conclusion, the data presented here indicate that Hz formation is an ancestral adaptation of Triatominae to a blood-sucking habit and that the presence of perimicrovillar membranes plays a central role in this process.
authors.affiliation: Instituto de Bioquímica Médica, Programa de Biotecnologia e Biologia Molecular, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ, 21941-590, Brazil. Electronic address: maroli@bioqmed.ufrj.br.
authors.forename: Marcus F
authors.initials: MF
authors.lastname: Oliveira
authors.affiliation: Instituto de Bioquímica Médica, Programa de Biotecnologia e Biologia Molecular, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ, 21941-590, Brazil.
authors.forename: Ana Caroline P
authors.initials: ACP
authors.lastname: Gandara
authors.affiliation: Petrobrás/CENPES, Divisão de Química, Setor de Química Orgânica, Cidade Universitária, Rio de Janeiro, RJ, 21949-900, Brazil.
authors.forename: Cláudia M S
authors.initials: CMS
authors.lastname: Braga
authors.affiliation: Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ, 28013-602, Brazil.
authors.forename: José R
authors.initials: JR
authors.lastname: Silva
authors.affiliation: Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ, 28013-602, Brazil.
authors.forename: Flavia B
authors.initials: FB
authors.lastname: Mury
authors.affiliation: Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ, 28013-602, Brazil.
authors.forename: Marílvia
authors.initials: M
authors.lastname: Dansa-Petretski
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fiocruz, Salvador, BA, Brazil.
authors.forename: Diego
authors.initials: D
authors.lastname: Menezes
authors.affiliation: Centro de Pesquisas Gonçalo Moniz, Fiocruz, Salvador, BA, Brazil.
authors.forename: Marcos A
authors.initials: MA
authors.lastname: Vannier-Santos
authors.affiliation: Instituto de Bioquímica Médica, Programa de Biotecnologia e Biologia Molecular, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ, 21941-590, Brazil.
authors.forename: Pedro L
authors.initials: PL
authors.lastname: Oliveira
mesh_terms: D000818:Animals; D003460:Crystallization; D005260:Female; D041981:Gastrointestinal Tract / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D006418:Heme / Q000032:analysis / Q000737:chemistry*; D006420:Hemeproteins / Q000032:analysis / Q000737:chemistry*; D007425:Intracellular Membranes / Q000737:chemistry / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D008871:Microvilli / Q000737:chemistry / Q000648:ultrastructure; D010860:Pigments, Biological / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014225:Triatominae / Q000502:physiology*
chemical_list: D006420:Hemeproteins; D010860:Pigments, Biological; C020753:hemozoin; D006418:Heme