title: Acquisition of exogenous haem is essential for tick reproduction.
abstract: Haem and iron homeostasis in most eukaryotic cells is based on a balanced flux between haem biosynthesis and haem oxygenase-mediated degradation. Unlike most eukaryotes, ticks possess an incomplete haem biosynthetic pathway and, together with other (non-haematophagous) mites, lack a gene encoding haem oxygenase. We demonstrated, by membrane feeding, that ticks do not acquire bioavailable iron from haemoglobin-derived haem. However, ticks require dietary haemoglobin as an exogenous source of haem since, feeding with haemoglobin-depleted serum led to aborted embryogenesis. Supplementation of serum with haemoglobin fully restored egg fertility. Surprisingly, haemoglobin could be completely substituted by serum proteins for the provision of amino-acids in vitellogenesis. Acquired haem is distributed by haemolymph carrier protein(s) and sequestered by vitellins in the developing oocytes. This work extends, substantially, current knowledge of haem auxotrophy in ticks and underscores the importance of haem and iron metabolism as rational targets for anti-tick interventions.
authors.affiliation: Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic.|Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Perner
authors.affiliation: Institute of Microbiology, Czech Academy of Sciences, Trebon, Czech Republic.
authors.forename: Roman
authors.initials: R
authors.lastname: Sobotka
authors.affiliation: Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic.
authors.forename: Radek
authors.initials: R
authors.lastname: Sima
authors.affiliation: Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic.|Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic.
authors.forename: Jitka
authors.initials: J
authors.lastname: Konvickova
authors.affiliation: Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sojka
authors.affiliation: Instituto de Bioquímica Médica Leopoldo de Meis, Programa de Biologia Molecular e Biotecnologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.|Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil, Brazil.
authors.forename: Pedro Lagerblad de
authors.initials: PL
authors.lastname: Oliveira
authors.affiliation: Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Hajdusek
authors.affiliation: Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Kopacek
mesh_terms: D000818:Animals; D005298:Fertility; D006418:Heme / Q000378:metabolism*; D012098:Reproduction; D013987:Ticks / Q000378:metabolism / Q000502:physiology*
chemical_list: D006418:Heme
keywords: biochemistry; haem auxotrophy; haem oxygenase; haematophagy; infectious disease; iron metabolism; microbiology; ticks