title: Solving a Bloody Mess: B-Vitamin Independent Metabolic Convergence among Gammaproteobacterial Obligate Endosymbionts from Blood-Feeding Arthropods and the Leech Haementeria officinalis.
abstract: Endosymbiosis is a common phenomenon in nature, especially between bacteria and insects, whose typically unbalanced diets are usually complemented by their obligate endosymbionts. While much interest and focus has been directed toward phloem-feeders like aphids and mealybugs, blood-feeders such as the Lone star tick (Amblyomma americanum), Glossina flies, and the human body louse (Pediculus humanus corporis) depend on obligate endosymbionts which complement their B-vitamin-deficient diets, and thus are required for growth and survival. Glossiphoniid leeches have also been found to harbor distinct endosymbionts housed in specialized organs. Here, we present the genome of the bacterial endosymbiont from Haementeria officinalis, first of a glossiphoniid leech. This as-yet-unnamed endosymbiont belongs to the Gammaproteobacteria, has a pleomorphic shape and is restricted to bacteriocytes. For this bacterial endosymbiont, we propose the name Candidatus Providencia siddallii. This symbiont possesses a highly reduced genome with high A+T content and a reduced set of metabolic capabilities, all of which are common characteristics of ancient obligate endosymbionts of arthropods. Its genome has retained many pathways related to the biosynthesis of B-vitamins, pointing toward a role in supplementing the blood-restricted diet of its host. Through comparative genomics against the endosymbionts of A. americanum, Glossina flies, and P. humanus corporis, we were able to detect a high degree of metabolic convergence among these four very distantly related endosymbiotic bacteria.
authors.affiliation: Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Manzano-Marín
authors.affiliation: Laboratorio de Helmintología, Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Distrito Federal, Mexico aoceguera@ib.unam.mx.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Oceguera-Figueroa
authors.affiliation: Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain Área de Genómica y Salud de la Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO), Valencia, Spain.
authors.forename: Amparo
authors.initials: A
authors.lastname: Latorre
authors.affiliation: Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Distrito Federal, Mexico.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Jiménez-García
authors.affiliation: Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain Área de Genómica y Salud de la Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO), Valencia, Spain.
authors.forename: Andres
authors.initials: A
authors.lastname: Moya
mesh_terms: D000818:Animals; D004269:DNA, Bacterial / Q000235:genetics; D004175:Diptera / Q000382:microbiology*; D020563:Gammaproteobacteria / Q000235:genetics* / Q000378:metabolism*; D016680:Genome, Bacterial; D006801:Humans; D007865:Leeches / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011532:Providencia / Q000235:genetics / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013559:Symbiosis; D014815:Vitamins / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D014815:Vitamins
keywords: B-vitamin; Haementeria officinalis; Providencia siddallii; blood-feeder; genome reduction; leech endosymbiont