Female Hosts Research Articles

Variation of parasitism patterns in bats during hibernation: the effect of host species, resources, health status, and hibernation period.

During critical periods of food shortage or variable climatic conditions, the choice of an appropriate host can increase the survival and reproductive performance of parasites. In turn, one of the unique adaptations to periodical food shortages is hibernation, which is often found among insectivorous bat species in the temperate zone. While hibernating, bats are completely defenseless against both predators and ectoparasites, their immune and endocrine systems are diminished, and survival is dependent on the accumulated fat reserves. Differences in the health status or in the rate of consumption of the resources might also explain species-specific differences in ectoparasite abundance, especially between closely related host species, such as the greater mouse-eared bat (Myotis myotis) and the lesser mouse-eared bat (M. blythii) during hibernation. In the present study, the abundance of two ecologically distinct (summer and winter) types of ectoparasites was examined in terms of its influence on the body condition and hemoglobin content of the two host species. The effects of demographic factors, such as host sex and age, were also investigated. Despite a similar pattern of deteriorating body condition and hemoglobin concentration, M. myotis was more parasitized than was M. blythii. The marked decrease in hemoglobin content in first-year females of both host species correlated with the highest parasite load and indicated a risk of anemia. At the intraspecific level, ectoparasite abundance was not correlated with body condition (resources), but it negatively affected hemoglobin content; however, this mostly concerned M. blythii, which had a lower parasite load. Therefore, it can be concluded that interspecific differences in ectoparasite abundance may result from parasites selecting the host species that is less sensitive to their activity. In turn, in summer ectoparasites, the preference for female hosts is probably attributable to the likelihood of reinfection rather than to an effect of host resources or health status. The absence of sex-based preferences in winter ectoparasites could be explained by equal host availability.

Epicarideos de Baja California: distribución y notas ecológicas de Probopyrus pandalicola (Packard, 1879) en el Pacífico oriental.

The distribution of Probopyrus pandolicola (Packard, 1879), (hast. Palaemon ritteri Holmes), is extended from Rio Chiriqui, Peninsula Burica, Panama, to near Puertecitos, Baja California (Gulf of California), Mexico. A greater percentage of male than female hosts are infested (P < 0.0001), but larger females (carapace length more than 6.5 mm) were most heavily infested. Female P. pandalicola present a random distribution (coefficient of dispersion s2/x near to 1) throughout the host population, which is atypical to the host-bopyrid relationship, All infested hosts carried only a female parasite each. We suspect that P. pandalicola is exotic for the Pacifico A list of the epicaridean isopods recorded from the Mexican Pacific is included.

Why Antagonistic Traits against Cytoplasmic Incompatibility Are So Elusive.

Intracellular symbionts are present in a wide variety of animals, plants and other life forms (Correa and Ballard, 2016); and have an intriguing lifestyle. To enhance their spread, intracellular symbionts have evolved a variety of mechanisms. Some of them provide benefits to their host and are effectively mutualists (e.g., Buchnera in aphids; Douglas, 1998), while others bias the sex ratio of the hosts' offspring toward females (e.g., Wolbachia in many insects; Reuter et al., 2008; Werren et al., 2008; Zug and Hammerstein, 2015). In the latter, the mode of transmission is strictly maternal. Therefore, such symbionts induce their female hosts to produce higher numbers of daughters than the average number produced in the population (Reuter et al., 2008). A more indirect strategy impedes reproduction of uninfected females, where infected males that mate with uninfected females render the female sterile by cytoplasmic incompatibility (CI; Werren et al., 2008). CI is a type of conditional sterility independently evolved in two bacteria: Wolbachia (Alphaproteobacteria) and Cardinium (Bacteroidetes) that infect arthropod hosts (Penz et al., 2012; Santos-Garcia et al., 2014). CI occurs when a host gamete from an infected male fuses with the gamete of either an uninfected female or that of a female infected with a different strain typically resulting embryonic death (Tram and Sullivan, 2002; Werren et al., 2008; Correa and Ballard, 2016). As a consequence, the infection frequency increases in the population due to reduced fitness of uninfected females instead of any direct benefit to infected females (Champion de Crespigny et al., 2005). Such costs in fitness led many authors to speculate that antagonistic strategies could have evolved in the host against the symbiont (Turelli, 1994; Charlat et al., 2003; Vala et al., 2004; Crespigny and Wedell, 2007; Champion de Crespigny et al., 2008), although most of the studies have failed to confirm antagonisms that evolved exclusively in response to CI-phenotype (Vala et al., 2004; Crespigny and Wedell, 2007). Antagonistic strategies include any strategy against the CI-phenotype through either avoidance or resistance mechanisms. Moreover, when the evolution of such strategies was modeled, the results were varied; showing that evolution of CI-antagonism is conditional, for instance, it could depend on the frequency of CI in the population (see Champion de Crespigny et al., 2005, 2008). Therefore, it remains unclear whether the evolution of such strategies is possible. Hereby, I provide a conceptual framework taking in consideration that infection frequency affects the proportion of a population under selection for CI-antagonism; this may explain why CI-antagonistic traits have been so elusive.

Mite choice generates sex- and size-biased infection in Drosophila hydei.

Heterogeneities in parasite infection among conspecific hosts often manifest as sex- or size-biased infections, which are typically attributed to differential host susceptibility and exposure. Since parasite fitness is often tied to host quality, host preference by parasites is likely to be under strong selection. We test the hypothesis that host preference is sufficient to generate variability in infection rate among conspecifics. Specifically, we ask whether the mite Macrocheles muscaedomesticae is able to discriminate between Drosophila hydei hosts of different sex and size, while explicitly accounting for the potential confounding effects of these two factors. Our results indicate a preference for female hosts, but this preference appears to be driven by size and not sex per se. When differences in body size were controlled for, the sex-biased infection disappeared, while mites presented with the choice of two female flies of disparate sizes were more likely to select the larger host. Across the distribution of fly body weight in this study, mites preferentially attached to flies of intermediate size. This study provides evidence that mite choice for certain host types can play an important role in parasite transmission, even in the absence of differential susceptibility or exposure among hosts.

Unidirectional Cytoplasmic Incompatibility in MalaysianAedes albopictus(Diptera: Culicidae)

Aedes albopictus (Skuse) is a secondary vector of dengue and has naturally occurring Wolbachia , which is an intracellular bacteria found in most nematodes and arthropods. Previous findings demonstrated that 91.60% of Malaysian Ae. albopictus were superinfected with two major Wolbachia supergroups, namely, w AlbA and w AlbB. Wolbachia has been associated with manipulation of reproductive phenotypes of their host such as male killing, parthenogenesis, feminization, and cytoplasmic incompatibility (CI). Cytoplasmic incompatibility is when no viable offspring are produced between Wolbachia -infected male and Wolbachia uninfected or differently infected female host. To evaluate CI, we performed a study in the laboratory using Wolbachia -free and Wolbachia -infected Ae. albopictus . Four different crosses were made, and viable eggs produced from each cross were recorded. The percentage of viable offspring produced were compared and analyzed. Results obtained suggest that native Wolbachia causes strong unidirectional CI in Malaysian Ae. albopictus . Perhaps this can be used as a possible vector control or suppression tool.

Butterfly oviposition preference is not related to larval performance on a polyploid herb.

The preference–performance hypothesis predicts that female insects maximize their fitness by utilizing host plants which are associated with high larval performance. Still, studies with several insect species have failed to find a positive correlation between oviposition preference and larval performance. In the present study, we experimentally investigated the relationship between oviposition preferences and larval performance in the butterfly Anthocharis cardamines. Preferences were assessed using both cage experiments and field data on the proportion of host plant individuals utilized in natural populations. Larval performance was experimentally investigated using larvae descending from 419 oviposition events by 21 females on plants from 51 populations of two ploidy types of the perennial herb Cardamine pratensis. Neither ploidy type nor population identity influenced egg survival or larval development, but increased plant inflorescence size resulted in a larger final larval size. There was no correlation between female oviposition preference and egg survival or larval development under controlled conditions. Moreover, variation in larval performance among populations under controlled conditions was not correlated with the proportion of host plants utilized in the field. Lastly, first instar larvae added to plants rejected for oviposition by butterfly females during the preference experiment performed equally well as larvae growing on plants chosen for oviposition. The lack of a correlation between larval performance and oviposition preference for A. cardamines under both experimental and natural settings suggests that female host choice does not maximize the fitness of the individual offspring.

Relationships between host body condition and immunocompetence, not host sex, best predict parasite burden in a bat-helminth system

Sex-biased parasitism highlights potentially divergent approaches to parasite resistance resulting in differing energetic trade-offs for males and females; however, trade-offs between immunity and self-maintenance could also depend on host body condition. We investigated these relationships in the big brown bat, Eptesicus fuscus, to determine if host sex or body condition better predicted parasite resistance, if testosterone levels predicted male parasite burdens, and if immune parameters could predict male testosterone levels. We found that male and female hosts had similar parasite burdens and female bats scored higher than males in only one immunological measure. Top models of helminth burden revealed interactions between body condition index and agglutination score as well as between agglutination score and host sex. Additionally, the strength of the relationships between sex, agglutination, and helminth burden is affected by body condition. Models of male parasite burden provided no support for testosterone predicting helminthiasis. Models that best predicted testosterone levels did not include parasite burden but instead consistently included month of capture and agglutination score. Thus, in our system, body condition was a more important predictor of immunity and worm burden than host sex.

Transcriptome and Expression Patterns of Chemosensory Genes in Antennae of the Parasitoid Wasp Chouioia cunea

Chouioia cunea Yang is an endoparasitic wasp that attacks pupae of Hyphantria cunea (Drury), an invasive moth species that severely damages forests in China. Chemosensory systems of insects are used to detect volatile chemical odors such as female sex pheromones and host plant volatiles. The antennae of parasite wasps are important for host detection and other sensory-mediated behaviors. We identified and documented differential expression profiles of chemoreception genes in C. cunea antennae. A total of 25 OBPs, 80 ORs, 10 IRs, 11 CSP, 1 SNMPs, and 17 GRs were annotated from adult male and female C. cunea antennal transcriptomes. The expression profiles of 25 OBPs, 16 ORs, and 17 GRs, 5 CSP, 5 IRs and 1 SNMP were determined by RT-PCR and RT-qPCR for the antenna, head, thorax, and abdomen of male and female C. cunea. A total of 8 OBPs, 14 ORs, and 8 GRs, 1 CSP, 4 IRs and 1 SNMPs were exclusively or primarily expressed in female antennae. These female antennal-specific or dominant expression profiles may assist in locating suitable host and oviposition sites. These genes will provide useful targets for advanced study of their biological functions.

Life-cycle of Choniomyzon inflatus Wakabayashi, Otake, Tanaka & Nagasawa, 2013 (Copepoda: Siphonostomatoida: Nicothoidae) with the morphological descriptions of the nauplius, copepodid and adult male.

Choniomyzon inflatus Wakabayashi, Otake, Tanaka & Nagasawa, 2013 (Copepoda: Siphonostomatoida: Nicothoidae), an associate of the scyllarid lobster Ibacus novemdentatus Gibbes, was found to pass through at least four developmental stages: nauplius, copepodid I (CI), copepodid II or later (CII+) and adult. Free-living nauplii were observed hatching from the ovisacs of adult females. CI was found on the body surface of both female and male hosts, whereas CII+ and adult were obtained from the female host's egg masses. The life-cycle of this copepod is presumed to be as follows: (i) nauplius develops into CI in the water column; (ii) infective CI settles on body surface of host; (iii) CI moults into the following stage, changing its microhabitat from host's body surface to egg masses; (iv) CII+ develops on egg masses of host until adult stage; and (v) adult female and male mate on the host's egg masses.

Tendency and consequences of superparasitism for the parasitoid Ooencyrtus pityocampae (Hymenoptera: Encyrtidae) in parasitizing a new laboratory host, Philosamia ricini (Lepidoptera: Saturniidae)

The tendency for self-superparasitism and it's effects on the quality of the parasitoid Ooencyrtus pityocampae (Mercet) (Hymenoptera: Encyrtidae) in parasitizing a new laboratory host, Philosamia ricini (Danovan) (Lepidoptera: Saturniidae), were investigated. In this study, female parasitoids of various ages (1-, 3- and 5-day-old) were tested individually. Parasitoids were provided with 1-day-old P. ricini eggs at ratios of 5, 10, 20, 30 and 40 host eggs per wasp. The tendency to superparasitize was dependent on the female's age and host density. Five-day-old females showed a strong tendency to superparasitize at low host densities. The development time of wasps in superparasitized eggs was longer than that of wasps in singly parasitized eggs. The size and longevity of adult parasitoids decreased significantly with superparasitism. This work contributes to the development of an efficient mass rearing and laboratory rearing of the parasitoid O. pityocampae using a new host.

Effects of infestation by Argeia pugettensis Dana, 1853 (Isopoda, Bopyridae) on the growth and reproduction of the sand shrimp Crangon hakodatei Rathbun, 1902 (Decapoda, Crangonidae) in South Korea

This study investigated possible parasitic effects on growth, reproduction and external sexual characters induced by a bopyrid isopod Argeia pugettensis Dana, 1853, which parasitizes the branchial chamber of the sand shrimp Crangon hakodatei Rathbun, 1902 in South Korea. Total infestation rate was 5.7%. The sizes of infected female and male hosts were similar compared to those of uninfected hosts. A. pugettensis showed size-specific selection for hosts. The relationship between host and parasite length was significantly positive. Several effects of parasitization were observed on C. hakodatei parasitized by A. pugettensis. In female hosts, parasitic effects were observed in growth (increased growth), internal organ development (immature gonads) and external sexual characters (no breeding dress). In male hosts, parasitic effects were observed on growth (increased growth) and development of external sexual characters (smaller appendix masculina).

两种Eupristina属小蜂对宿主榕果挥发物和合成信息素的行为反应

PDF HTML阅读 XML下载 导出引用 引用提醒 两种Eupristina属小蜂对宿主榕果挥发物和合成信息素的行为反应 DOI: 10.5846/stxb201502130355 作者: 作者单位: 福建师范大学生命科学学院,福建师范大学生命科学学院,福建师范大学生命科学学院,福建师范大学生命科学学院,福建师范大学生命科学学院,福建师范大学生命科学学院,福建师范大学生命科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金重点资助项目（31270440）；福建师范大学生物学拔尖人才班科研项目；国家级、省级大学生创新训练计划项目 Responses of two Eupristina wasp species to fig volatiles of Ficus altissima and infochemicals Author: Affiliation: College of Life Science,Fujian Normal University,College of Life Science,Fujian Normal University,College of Life Science,Fujian Normal University,College of Life Science,Fujian Normal University,College of Life Science,Fujian Normal University,College of Life Science,Fujian Normal University,College of Life Science,Fujian Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:高榕，雌雄同株，与其共生的形态高度相似的传粉小蜂Eupristina altissima与非传粉小蜂Eupristina sp.均为果内产卵。利用Y型嗅觉仪生物测定法研究E.altissima和Eupristina sp.对不同发育期高榕榕果挥发物以及合成信息素混合物的行为反应差异。结果表明：E.altissima和Eupristina sp.对高榕雌花期榕果挥发物具极显著趋向行为，对高榕雄花期榕果挥发物具极显著驱避行为，表明E.altissima与Eupristina sp.雌蜂能够敏锐辨别高榕雌花期和雄花期榕果的挥发物，快速远离雄花期榕果，并实现对宿主雌花期榕果的定位。但是，E.altissima与Eupristina sp.对其它发育时期榕果挥发物的行为反应具有差异性，前者对雌前期榕果和传粉或产卵后榕果释放的挥发物存在显著的趋避反应，而后者无明显的行为偏向性，表明E.altissima能够识别雌前期榕果和传粉或产卵后榕果，可避免误入其中而无法繁殖后代，Eupristina sp.则不具备这种识别能力。E.altissima和Eupristina sp.小蜂对合成信息素的行为反应也高度相似，表现为芳樟醇、苯乙烯，以及苯乙烯和金合欢醇的交互作用对两种小蜂选择行为影响显著，组合A1B2C2（0.5% Linalool+1% Benzyl ethylene+1% Farnesol）的混合信息素对两种小蜂具有极显著的驱避作用，而组合A2B1C1（1% Linalool+0.5% Benzyl ethylene+0.5% Farnesol），A2B1C2（1% Linalool+0.5% Benzyl ethylene+1% Farnesol），A2B2C1（1% Linalool+1% Benzyl ethylene+0.5% Farnesol）的混合信息素对其具有极显著的吸引作用，但两种小蜂对组合A1B1C1（0.5% Linalool+0.5% Benzyl ethylene+0.5% Farnesol）的行为反应存在差异。两种小蜂对榕果挥发物和合成信息素的反应异同，可能与其触角结构的差异密切相关。研究结果为探究榕-蜂共生体系的化学信号传导机制提供科学依据。 Abstract:Fig trees are pollinated by fig wasps, which also oviposit in female flowers. They had formed obligate mutualism in their long co-evolution process. Ficus altissima (Ficus, Moraceae) is a monoecious fig plant, both the pollinating Eupristina altissima and non-pollinating Eupristina sp. symbiosis with Ficus altissima were oviposited within the syconia. Pollinating Eupristina altissima and non-pollinating Eupristina sp were highly similar in morphology, only with a slight difference on body color, antenna, fore leg coxal comb and pollen pocket for their female wasps, no morphological differences found so far between their male wasps. Fig wasps mainly located their hosts by recognizing the chemical signal released from the syconia. Also the encounter of the mating partners is fundamental for the stability of their interaction, In this study, we applied a Y-tube (binary choice) olfactometer to test the responses of E. altissima and Eupristina sp. to fig volatiles of different developmental phase of Ficus altissima and infochemical mixture. Results showed that:(1) both E. altissima and Eupristina sp. represented significant preference to the fig volatiles of female syconia, and repelled to the fig volatiles of male flower phase syconia, indicating that E. altissima and Eupristina sp. can distinguish female flower phase syconia of Ficus altissima from the male one, and keep away from the male phase syconia in order to quickly localized its female host. Observation showed there are differences responses to fig volatiles of the other developmental phase between two wasp species. E. altissima significantly repelled to the fig volatiles of pre-female phase and post-pollinated or oviposited phase, while Eupristina sp. showed no significant preference between them, which indicated that E. altissima was able to recognize the syconia of pre-female phase and post-pollinated or oviposited phase and avoid entering into them, while Eupristina sp. can not. (2) E. altissima and Eupristina sp. also showed similary responses to infochemicals linalool, benzyl ethylene The interation of benzyl ethylene and farnesol significantly affected the choice behavior of both the two wasp species. Both wasp species repelled mix infochemicals of group A1B2C2(0.5% Linalool+1% Benzyl ethylene+1% Farnesol) significantly and significantly attracted by mix infochmicals of group A2B1C1(1% Linalool+0.5% Benzyl ethylene+0.5% Farnesol), A2B1C2(1% Linalool+0.5% Benzyl ethylene+1% Farnesol), A2B2C1(1% Linalool+1% Benzyl ethylene+0.5% Farnesol), while two wasp species showed difference responses to mix infochemical of group A1B1C1(0.5% Linalool+0.5% Benzyl ethylene+0.5% Farnesol). Above all, the two different wasp species can discriminate different volatile signals, and E. altissima was more favor to the fig volatiles of their host than Eupristina sp., therefore, E. altissima was able to locate their host more accurately than Eupristina sp. The different responses of E. altissima and Eupristina sp. to the fig volatiles and infochemicals may related to the different structure of their antenna. Our result will provide a scientific basis to the studies of chemical signaling mechanism of fig-wasp mutualism. 参考文献 相似文献 引证文献

Occurrence of Caryophyllaeid parasite species (Plathelminthes) in chub, Squalis cephalus, of Serban Dam Lake, Turkey: including a new host and a new locality

An examination was conducted on caryophyllaeid cestode fauna of Squalius cephalus obtained from Serban Dam Lake in Turkey between February 2009 and August 2010. At the end of the study, from the 114 S. Cephalus examined, 14 host fish specimens were infected with 75 Caryophyllaeus brachycollis (prevalence 12.3% and mean parasite intensity 5.3 ± 10.0 parasites/fish) and one host fish specimen was infected with 65 Biacetabulum appendiculatum (prevalence 0.9%, 65 parasites). Infection data of the parasite species were evaluated for seasons, host fish size, and sex. The period of the study covered the four seasons: spring, summer, fall, and winter. The infection values of C. Brachycollis changed according to seasonal conditions, except for fall. Prevalence of infection and mean intensity of the species were maximum in spring. Host fish specimens were divided into four groups according to their size. The occurrence of C. Brachycollis was recorded in III, V and VI groups. The highest infection prevalence and mean intensity were seen in age group VI. C. Brachycollis was recorded in both male and female hosts, but the occurrence of parasites was higher in females. The other species, Biacetabulum appendiculatum, was found in only one host fish specimen that belonged to group V according to its size in spring. According to the results of this study, among these species, Caryophyllaeus brachycollis is observed for the first time in Turkey, and Biacetabulum appendiculatum is a new parasite species record for S. Cephalus in Turkey. Thus, a new locality and a new host fish species have been added to the geographical invasions by the two caryophyllaeid species.

Growth of the Sirex-parasitic nematode Deladenus siricidicola on the white rot fungus Amylostereum

The Kamona strain of the nematode Deladenus siricidicola has been extensively used as a biological control agent against invasive Sirex noctilio woodwasps in the Southern Hemisphere, where it sterilizes female hosts. In North America, a non-sterilizing (NS) strain of D. siricidicola, thought to have been introduced with S. noctilio, is commonly found parasitizing this invasive woodwasp. Species of Deladenus that parasitize Sirex have a parasitic form, as well as a mycophagous form. The mycophagous form feeds on Sirex fungal symbionts in the genus Amylostereum. The goal of this study was to compare reproduction of NS and Kamona D. siricidicola when feeding on four isolates of Amylostereum areolatum (three introduced and one native in North America) and one native strain of Amylostereum chailletii isolated from Sirex nigricornis. Mycophagous forms of the two D. siricidicola strains displayed relatively similar production of offspring when feeding on most of the A. areolatum found associated with S. noctilio in this continent, except for strain BD on which NS produced more offspring than the biological control strain Kamona. Growth of both nematodes was greater on the introduced versus the native A. areolatum isolates.

Seroprevalence of Haemoprotozoan diseases in ruminants of Kashmir valley

The study was designed to investigate the seroprevalence of haemoparasites ( Babesia , Anaplasma and Theileria ) among ruminants from Kashmir valley for a period of two years. A total of 585 blood samples were collected from selected small holders and private livestock farms using multistage cluster random sampling technique. EDTA containing, methanol fixed and Giemsa (1:10) stained thin peripheral blood smears were microscopically examined. Microscopic examinations showed the overall 74(29.83%), 9(4.29%) and 3(2.27%) seroprevalence of haemoparasitic infection in cattle, sheep and goats respectively. Prevalence of Babesia , Anaplasma and Theileria in cattle were 33(13.30%), 18(7.25%) and 23(9.27%) and in sheep 5(2.43%), 1(0.487%) and 3(1.46%) respectively. In goats the prevalence of Babesia and Theileria was 1(0.75%) and 2(1.51%). Age-wise epidemiological observations revealed highest prevalence rate in 1-5 years age group in cattle Overall gender-wise prevalence was not much prominent but female hosts were found to be more infected than males. The highest 56.71% prevalence of haemoparasitic diseases was found in exotic cattle with zero prevalence in local sheep.

Differential Octopaminergic Modulation of Olfactory Receptor Neuron Responses to Sex Pheromones in Heliothis virescens.

Octopamine is an important neuromodulator of neural function in invertebrates. Octopamine increases male moth sensitivity to female sex pheromones, however, relatively little is known as to the role of octopamine in the female olfactory system, nor its possible effects on the reception of non-pheromone odorants. The purpose of this study was to determine relative effects of octopamine on the sensitivity of the peripheral olfactory system in male and female Heliothis virescens. Single sensillum recording was conducted in both sexes following injection with octopamine or Ringer solution, and during odorant stimulation with conspecific female sex pheromone or host plant volatiles. Results indicate that octopamine plays a significant modulatory role in female sex pheromone detection in female moths; and that male and female pheromone detection neurons share distinct pharmacological and physiological similarities in H. virescens despite sexual dimorphism at the antennal level.

The impacts of Wolbachia and the microbiome on mate choice in Drosophila melanogaster.

Symbionts and parasites can manipulate their hosts' reproduction to their own benefit, profoundly influencing patterns of mate choice and evolution of the host population. Wolbachia is one of the most widespread symbionts among arthropods, and one that alters its hosts' reproduction in diverse and dramatic ways. While we are beginning to appreciate how Wolbachia's extreme manipulations of host reproduction can influence species diversification and reproductive isolation, we understand little about how symbionts and Wolbachia, in particular, may affect intrapopulation processes of mate choice. We hypothesized that the maternally transmitted Wolbachia would increase the attractiveness of its female hosts to further its own spread. We therefore tested the effects of Wolbachia removal and microbiome disruption on female attractiveness and male mate choice among ten isofemale lines of Drosophila melanogaster. We found variable effects of general microbiome disruption on female attractiveness, with indications that bacteria interact with hosts in a line-specific manner to affect female attractiveness. However, we found no evidence that Wolbachia influence female attractiveness or male mate choice among these lines. Although the endosymbiont Wolbachia can greatly alter the reproduction of their hosts in many species, there is no indication that they alter mate choice behaviours in D.melanogaster.

The solution structure of the soluble form of the lipid-modified azurin from Neisseria gonorrhoeae, the electron donor of cytochrome c peroxidase

Neisseria gonorrhoeae colonizes the genitourinary track, and in these environments, especially in the female host, the bacteria are subjected to low levels of oxygen, and reactive oxygen and nitrosyl species. Here, the biochemical characterization of N. gonorrhoeae Laz is presented, as well as, the solution structure of its soluble domain determined by NMR. N. gonorrhoeae Laz is a type 1 copper protein of the azurin-family based on its spectroscopic properties and structure, with a redox potential of 277±5mV, at pH7.0, that behaves as a monomer in solution. The globular Laz soluble domain adopts the Greek-key motif, with the copper center located at one end of the β-barrel coordinated by Gly48, His49, Cys113, His118 and Met122, in a distorted trigonal geometry. The edge of the His118 imidazole ring is water exposed, in a surface that is proposed to be involved in the interaction with its redox partners. The heterologously expressed Laz was shown to be a competent electron donor to N. gonorrhoeae cytochrome c peroxidase. This is an evidence for its involvement in the mechanism of protection against hydrogen peroxide generated by neighboring lactobacilli in the host environment.

Differential temporal changes of primary and secondary bacterial symbionts and whitefly host fitness following antibiotic treatments.

Where multiple symbionts coexist in the same host, the selective elimination of a specific symbiont may enable the roles of a given symbiont to be investigated. We treated the Mediterranean species of the whitefly Bemisia tabaci complex by oral delivery of the antibiotic rifampicin, and then examined the temporal changes of its primary symbiont “Candidatus Portiera aleyrodidarum” and secondary symbiont “Ca. Hamiltonella defensa” as well as host fitness for three generations. In adults treated with rifampicin (F0), the secondary symbiont was rapidly reduced, approaching complete disappearance as adults aged. In contrast, the primary symbiont was little affected until later in the adult life. In the offspring of these adults (F1), both symbionts were significantly reduced and barely detectable when the hosts reached the adult stage. The F1 adults laid few eggs (F2), all of which failed to hatch. Mating experiments illustrated that the negative effects of rifampicin on host fitness were exerted via female hosts but not males. This study provides the first evidence of differential temporal reductions of primary and secondary symbionts in whiteflies following an antibiotic treatment. Studies that disrupt functions of bacterial symbionts must consider their temporal changes.

Molecular Characterization and Expression Profiling of Odorant-Binding Proteins in Apolygus lucorum.

Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) is one of the most important agricultural pests, with broad host range and cryptic feeding habits in China. Chemosensory behavior plays an important role in many crucial stages in the life of A. lucorum, such as the detection of sex pheromone cues during mate pursuit and fragrant odorants during flowering host plant localization. Odorant-binding proteins (OBPs) are involved in the initial biochemical recognition steps in semiochemical perception. In the present study, a transcriptomics-based approach was used to identify potential OBPs in A. lucorum. In total, 38 putative OBP genes were identified, corresponding to 26 ‘classic’ OBPs and 12 ‘Plus-C’ OBPs. Phylogenetic analysis revealed that A. lucorum OBP proteins are more closely related to the OBP proteins of other mirid bugs as the same family OBP clustering together. Quantitative real-time PCR analysis for the first reported 23 AlucOBPs revealed that the expression level of 11 AlucOBP genes were significantly higher in antennae of both sexes than in other tissues. Three of them were male antennae-biased and six were female antennae-biased, suggesting their putative roles in the detection of female sex pheromones and host plant volatiles. In addition, three, four, two and one AlucOBPs had the highest degree of enrichment in the stylet, head, leg, and in abdomen tissues, respectively. Two other OBPs were ubiquitously expressed in the main tissues, including antennae, stylets, heads, legs and wings. Most orthologs had similar expression patterns, strongly indicating that these genes have the same function in olfaction and gustation.