title: "CandidatusGortzia shahrazadis", a Novel Endosymbiont ofParamecium multimicronucleatumand a Revision of the Biogeographical Distribution ofHolospora-Like Bacteria.
abstract: Holosporaspp. and "CandidatusGortzia infectiva", known asHolospora-like bacteria (HLB), are commonly found as nuclear endosymbionts of ciliates, especially theParameciumgenus. HLB are related by phylogenetic relationships, morphological features, and life-cycles, which involve two alternating morphotypes: reproductive and infectious forms (RF, IF). In this paper we describe a novel species belonging to the "Ca. Gortzia" genus, detected inP. multimicronucleatum, a ciliate for which infection by an HLB has not been reported, discovered in India. This novel endosymbiont shows unusual and surprising features with respect to other HLB, such as large variations in IF morphology and the occasional ability to reproduce in the host cytoplasm. We propose the name of "CandidatusGortzia shahrazadis" for this novel HLB. Moreover, we report two additional species of HLB from IndianParameciumpopulations: "Ca. Gortzia infectiva" (fromP. jenningsi), andH. obtusa(fromP. caudatum); the latter is the first record ofHolosporafrom a tropical country. Although tropical, we retrievedH. obtusaat an elevation of 706 m corresponding to a moderate climate not unlike conditions whereHolosporaare normally found, suggesting the genusHolosporadoes exist in tropical countries, but restricted to higher elevations.
authors.affiliation: Department of Biology, University of Pisa Pisa, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Serra
authors.affiliation: Department of Biology, University of PisaPisa, Italy; Department of Invertebrate Zoology, Saint Petersburg State UniversitySaint Petersburg, Russia.
authors.forename: Sergei I
authors.initials: SI
authors.lastname: Fokin
authors.affiliation: Department of Biology, University of PisaPisa, Italy; Department of Veterinary Medicine, University of MilanMilan, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Castelli
authors.affiliation: Department of Zoology, Andhra University Visakhapatnam, India.
authors.forename: Charan K
authors.initials: CK
authors.lastname: Basuri
authors.affiliation: Department of Zoology, Andhra University Visakhapatnam, India.
authors.forename: Venkatamahesh
authors.initials: V
authors.lastname: Nitla
authors.affiliation: Department of Biology, University of Pisa Pisa, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Verni
authors.affiliation: Department of Zoology, Andhra UniversityVisakhapatnam, India; Department of Biotechnology, Andhra UniversityVisakhapatnam, India.
authors.forename: Bhagavatula V
authors.initials: BV
authors.lastname: Sandeep
authors.affiliation: Department of Zoology, Andhra University Visakhapatnam, India.
authors.forename: Chaganti
authors.initials: C
authors.lastname: Kalavati
authors.affiliation: Department of Biology, University of Pisa Pisa, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Petroni
keywords: Gortzia; Holospora; India; Paramecium; bacteria; distribution; endosymbiosis