title: Consequences of Nosema apis infection for male honey bees and their fertility.
abstract: The queens of eusocial bees, ants and wasps mate only during a very short period early in life and males therefore produce ejaculates consisting of large numbers of high quality sperm. Such extreme selection for high fecundity resulted in males investing minimally into their somatic survival, including their immune system. However, if susceptible males are unable to protect their reproductive tissue from infections, they compromise queen fitness if they transfer pathogens during mating. We used the honey bee Apis mellifera and investigated the course of infection of the sexually transmitted pathogen Nosema apis. We predicted that honey bee males are susceptible but protect their reproductive tissues from infections. We investigated the effects of N. apis infections on the midgut, the accessory glands and the accessory testes and quantified the consequences of infection on male survival and fecundity. We found that N. apis is able to infect males, and as infections progressed, it significantly impacted fertility and survival in older males. Even though we confirm males to be able to minimize N. apis infections of their reproductive tissues, the parasite is present in ejaculates of older males. Consequently N. apis evolved alternative routes to successfully infect ejaculates and get sexually transmitted.
authors.affiliation: Centre for Integrative Bee Research (CIBER), Bayliss Building M316, The University of Western Australia, Crawley, WA 6009, Australia.
authors.forename: Yan
authors.initials: Y
authors.lastname: Peng
authors.affiliation: Centre for Integrative Bee Research (CIBER), Bayliss Building M316, The University of Western Australia, Crawley, WA 6009, Australia.
authors.forename: Barbara
authors.initials: B
authors.lastname: Baer-Imhoof
authors.affiliation: ARC Centre of Excellence in Plant Energy Biology, Bayliss Building M316, The University of Western Australia, Crawley, WA 6009, Australia.
authors.forename: A Harvey
authors.initials: AH
authors.lastname: Millar
authors.affiliation: Centre for Integrative Bee Research (CIBER), Bayliss Building M316, The University of Western Australia, Crawley, WA 6009, Australia.
authors.forename: Boris
authors.initials: B
authors.lastname: Baer
mesh_terms: D000818:Animals; D001516:Bees / Q000382:microbiology*; D004271:DNA, Fungal / Q000032:analysis / Q000378:metabolism; D005298:Fertility; D007422:Intestines / Q000382:microbiology / Q000473:pathology; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D008853:Microscopy; D016818:Nosema / Q000235:genetics / Q000502:physiology*; D016133:Polymerase Chain Reaction; D013094:Spermatozoa / Q000382:microbiology / Q000502:physiology; D013172:Spores, Fungal / Q000302:isolation & purification; D013737:Testis / Q000382:microbiology / Q000473:pathology
chemical_list: D004271:DNA, Fungal