title: Three-dimensional visualisation of developmental stages of an apicomplexan fish blood parasite in its invertebrate host.
abstract: BACKGROUND
  Although widely used in medicine, the application of three-dimensional (3D) imaging to parasitology appears limited to date. In this study, developmental stages of a marine fish haemogregarine, Haemogregarina curvata (Apicomplexa: Adeleorina), were investigated in their leech vector, Zeylanicobdella arugamensis; this involved 3D visualisation of brightfield and confocal microscopy images of histological sections through infected leech salivary gland cells.
  
  
  RESULTS
  3D assessment demonstrated the morphology of the haemogregarine stages, their spatial layout, and their relationship with enlarged host cells showing reduced cellular content. Haemogregarine meronts, located marginally within leech salivary gland cells, had small tail-like connections to the host cell limiting membrane; this parasite-host cell interface was not visible in two-dimensional (2D) light micrographs and no records of a similar connection in apicomplexan development have been traced.
  
  
  CONCLUSIONS
  This is likely the first account of the use of 3D visualisation to study developmental stages of an apicomplexan parasite in its invertebrate vector. Elucidation of the extent of development of the haemogregarine within the leech salivary cells, together with the unusual connections between meronts and the host cell membrane, illustrates the future potential of 3D visualisation in parasite-vector biology.
authors: School of Life Sciences, Faculty of Science, Engineering and Computing, Kingston University, Kingston upon Thames, Surrey KT1 2EE, UK. p.hayes@kingston.ac.uk
authors: Polly M
authors: PM
authors: Hayes
authors: David F
authors: DF
authors: Wertheim
authors: Nico J
authors: NJ
authors: Smit
authors: Alan M
authors: AM
authors: Seddon
authors: Angela J
authors: AJ
authors: Davies
mesh_terms: D000818:Animals; D016782:Apicomplexa / Q000166:cytology / Q000254:growth & development*; D021621:Imaging, Three-Dimensional; D007865:Leeches / Q000469:parasitology*; D018613:Microscopy, Confocal; D012469:Salivary Glands / Q000166:cytology / Q000469:parasitology