title: Mineral deposition in bacteria-filled and bacteria-free calcium bodies in the crustacean Hyloniscus riparius (Isopoda: Oniscidea).
abstract: Crustacean calcium bodies are epithelial sacs which contain a mineralized matrix. The objectives of this study were to describe the microscopic anatomy of calcium bodies in the terrestrial isopod Hyloniscus riparius and to establish whether they undergo molt-related structural changes. We performed 3D reconstruction of the calcium bodies from paraffin sections and analyzed their structure with light and electron microscopy. In addition, we analyzed the chemical composition of their mineralized matrices with micro-Raman spectroscopy. Two pairs of these organs are present in H. riparius. One pair is filled with bacteria while the other pair is not. In non-molting animals, the bacteria-filled calcium bodies contain apatite crystals and the bacteria-free calcium bodies enclose CaCO3-containing concretions with little organic matrix. During preparation for molt, an additional matrix layer is deposited in both pairs of calcium bodies. In the bacteria-filled calcium bodies it contains a mixture of calcium carbonate and calcium phosphate, whereas only calcium carbonate is present in bacteria-free calcium bodies. After ecdysis, all mineral components in bacteria-free calcium bodies and the additional matrix layer in bacteria-filled calcium bodies are completely resorbed. During calcium resorption, the apical surface of the calcium body epithelium is deeply folded and electron dense granules are present in spaces between epithelial cells. Our results indicate that the presence of bacteria might be linked to calcium phosphate mineralization. Calcium bodies likely provide a source of calcium and potentially phosphate for the mineralization of the new cuticle after molt. Unlike other terrestrial isopods, H. riparius does not form sternal CaCO3 deposits and the bacteria-free calcium bodies might functionally replace them in this species.
authors.affiliation: Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia. milos.vittori@gmail.com
authors.forename: Miloš
authors.initials: M
authors.lastname: Vittori
authors.forename: Alenka
authors.initials: A
authors.lastname: Rozman
authors.forename: Jože
authors.initials: J
authors.lastname: Grdadolnik
authors.forename: Urban
authors.initials: U
authors.lastname: Novak
authors.forename: Jasna
authors.initials: J
authors.lastname: Štrus
mesh_terms: D000818:Animals; D001419:Bacteria / Q000378:metabolism; D002113:Calcification, Physiologic; D002118:Calcium / Q000378:metabolism*; D002119:Calcium Carbonate / Q000737:chemistry / Q000378:metabolism; D004848:Epithelium / Q000737:chemistry* / Q000378:metabolism* / Q000382:microbiology / Q000648:ultrastructure; D033321:Isopoda / Q000033:anatomy & histology* / Q000254:growth & development / Q000648:ultrastructure; D008903:Minerals / Q000378:metabolism*; D018978:Molting; D013059:Spectrum Analysis, Raman
chemical_list: D008903:Minerals; D002119:Calcium Carbonate; D002118:Calcium
references.citation: Stain Technol. 1960 Nov;35:313-23
references.pmid: 13741297
references.citation: J Struct Biol. 2009 Dec;168(3):426-36
references.pmid: 19632333
references.citation: Appl Environ Microbiol. 2005 Mar;71(3):1626-37
references.pmid: 15746368
references.citation: Arthropod Struct Dev. 2000 Jul;29(3):259-66
references.pmid: 18088931
references.citation: Cell Calcium. 2002 Jun;31(6):307-21
references.pmid: 12098220
references.citation: J Struct Biol. 2011 Jun;174(3):512-26
references.pmid: 21414408
references.citation: J Struct Biol. 2012 Oct;180(1):216-25
references.pmid: 22651964
references.citation: Arthropod Struct Dev. 2000 Jul;29(3):241-57
references.pmid: 18088930
references.citation: J Struct Biol. 2008 Jul;163(1):100-8
references.pmid: 18550385
references.citation: Calcif Tissue Int. 2007 Jul;81(1):46-52
references.pmid: 17551767
references.citation: Biol Bull. 1990 Dec;179(3):332-339
references.pmid: 29314961
references.citation: Nat Commun. 2012 May 15;3:839
references.pmid: 22588301
references.citation: J Microsc. 2005 Apr;218(Pt 1):52-61
references.pmid: 15817063
references.citation: Zookeys. 2012;(176):103-21
references.pmid: 22536102
references.citation: Biol Bull. 2002 Dec;203(3):269-74
references.pmid: 12480717
references.citation: Calcif Tissue Int. 2006 Nov;79(5):354-9
references.pmid: 17120187
references.citation: Micron. 2005;36(2):137-53
references.pmid: 15629645
references.citation: Proc Natl Acad Sci U S A. 2008 Nov 11;105(45):17362-6
references.pmid: 18987314
references.citation: Proc Natl Acad Sci U S A. 2011 Sep 6;108(36):14763-8
references.pmid: 21873244
references.citation: Cell Tissue Res. 1996 May 20;284(3):459-66
references.pmid: 8662354
references.citation: J Biomed Opt. 2000 Jul;5(3):259-68
references.pmid: 10958610
references.citation: Bone. 1999 Aug;25(2 Suppl):81S-84S
references.pmid: 10458282
references.citation: ISME J. 2010 Jul;4(7):922-32
references.pmid: 20182524
references.citation: Zookeys. 2012;(176):23-38
references.pmid: 22536097
references.citation: Talanta. 1996 Sep;43(9):1497-509
references.pmid: 18966629