Related Host Research Articles

Somewhere I belong: phylogeny and morphological evolution in a species-rich lineage of ectoparasitic flatworms infecting cichlid fishes.

A substantial portion of biodiversity has evolved through adaptive radiation. However, the effects of explosive speciation on species interactions remain poorly understood. Metazoan parasites infecting radiating host lineages could improve our knowledge because of their intimate host relationships. Yet limited molecular, phenotypic and ecological data discourage multivariate analyses of evolutionary patterns and encourage the use of discrete characters. Here, we assemble new molecular, morphological and host range data widely inferred from a species-rich lineage of parasites (Cichlidogyrus, Platyhelminthes: Monogenea) infecting cichlid fishes to address data scarcity. We infer a multimarker (28S/18S rDNA, ITS1, COI mtDNA) phylogeny of 58 of 137 species and characterize major lineages through synapomorphies inferred from mapping morphological characters. We predict the phylogenetic position of species without DNA data through shared character states, a morphological phylogenetic analysis, and a classification analysis with support vector machines. Based on these predictions and a cluster analysis, we assess the systematic informativeness of continuous characters, search for continuous equivalents for discrete characters, and suggest new characters for morphological traits not analysed to date. We also model the attachment/reproductive organ and host range evolution using the data for 136 of 137 described species and multivariate phylogenetic comparative methods (PCMs). We show that discrete characters not only can mask phylogenetic signals, but also are key for characterizing species groups. Regarding the attachment organ morphology, a divergent evolutionary regime for at least one lineage was detected and a limited morphological variation indicates host and environmental parameters affecting its evolution. However, moderate success in predicting phylogenetic positions, and a low systematic informativeness and high multicollinearity of morphological characters call for a revaluation of characters included in species characterizations.

Lobophorin Producing Endophytic Streptomyces olivaceus JB1 Associated With Maesa japonica (Thunb.) Moritzi & Zoll.

In this study, we focused on endophytes of Maesa japonica (Thunb.) Moritzi & Zoll. and the plant-microbe interaction at metabolite levels. We isolated seven endophytes associated with M. japonica (JB1−7), and focused on Streptomyces olivaceus JB1 because of antibacterial activities of its secondary metabolites. We confirmed lobophorin analogs production from the bacterial strain JB1 by using spectroscopic techniques such as NMR, UV, and LC/Q-TOF-MS. In the LC/MS system, thirteen reported lobophorin analogs and twelve unreported analogs were detected. Among metabolites, lobophorin A was clearly detected in the dried foliar residues of M. japonica which implies that JB1 resides in the host and accumulates its secondary metabolites likely interacting with the plant. Antimicrobial activity tests of the secondary metabolites against undesirable contaminants isolated from the external surface of M. japonica supported the host and microbe mutualistic relationship. In the meantime, lobophorin producing Streptomyces spp. were isolated from marine environments such as marine sediments, algae, corals, and sponges. As lobophorin producing Streptomyces is isolated commonly from marine environments, we conducted a saline water stress tolerance test with JB1 showing saline medium does not accelerate the growth of the bacterium.

Helminths of sigmodontine rodents in an agroforestry mosaic in the Brazilian Atlantic Forest: Patterns and processes of the metacommunity structure.

Phylogenetically or taxonomically related hosts may harbour similar parasite communities due to phylogenetic conservatism. In addition, host attributes may favour their exposure to parasites. This study aimed to characterize the helminth fauna of sigmodontine rodents in an Atlantic Forest area in northeastern Brazil and determine the pattern of the helminth metacommunity structure. The influence of host attributes and host taxonomy on the metacommunity structure was also investigated. The most abundant helminth species were Raillietina sp. and Hassalstrongylus lauroi. Euryoryzomys russatus was the most infected host species for helminth parasites, as approximately 81% (35/43) of the animals were infected by at least one helminth species. The helminth metacommunity structure was coherent at both the infracommunity and the component community scales, indicating that species responded to the same environmental gradient. A quasi-Clementsian pattern was observed for the infracommunities, indicating the occurrence of compartments of parasite species that were substituted along the environmental gradient, which was formed by host individuals. A quasi-Gleasonian pattern was found at the component community scale, showing random boundary clumping, which is consistent with the individualistic responses of parasite species to each host species. These patterns corroborated the high values of beta-diversity observed, indicating high species turnover among communities at both scales. Host taxonomic distance was the most important variable explaining the patterns of the helminth metacommunity structure.

Cross-reactive antibodies elicited to conserved epitopes on SARS-CoV-2 spike protein after infection and vaccination

SARS-CoV-2 is a novel betacoronavirus that caused coronavirus disease 2019 and has resulted in millions of deaths worldwide. Novel coronavirus infections in humans have steadily become more common. Understanding antibody responses to SARS-CoV-2, and identifying conserved, cross-reactive epitopes among coronavirus strains could inform the design of vaccines and therapeutics with broad application. Here, we determined that individuals with previous SARS-CoV-2 infection or vaccinated with the Pfizer-BioNTech BNT162b2 vaccine produced antibody responses that cross-reacted with related betacoronaviruses. Moreover, we designed a peptide-conjugate vaccine with a conserved SARS-CoV-2 S2 spike epitope, immunized mice and determined cross-reactive antibody binding to SARS-CoV-2 and other related coronaviruses. This conserved spike epitope also shared sequence homology to proteins in commensal gut microbiota and could prime immune responses in humans. Thus, SARS-CoV-2 conserved epitopes elicit cross-reactive immune responses to both related coronaviruses and host bacteria that could serve as future targets for broad coronavirus therapeutics and vaccines.

A Novel and Ubiquitous Marine Methylophage Provides Insights into Viral-Host Coevolution and Possible Host-Range Expansion in Streamlined Marine Heterotrophic Bacteria.

ABSTRACTThe methylotrophic OM43 clade are Gammaproteobacteria that comprise some of the smallest free-living cells known and have highly streamlined genomes. OM43 represents an important microbial link between marine primary production and remineralization of carbon back to the atmosphere. Bacteriophages shape microbial communities and are major drivers of mortality and global marine biogeochemistry. Recent cultivation efforts have brought the first viruses infecting members of the OM43 clade into culture. Here, we characterize a novel myophage infecting OM43 called Melnitz. Melnitz was isolated independently from water samples from a subtropical ocean gyre (Sargasso Sea) and temperate coastal (Western English Channel) systems. Metagenomic recruitment from global ocean viromes confirmed that Melnitz is globally ubiquitous, congruent with patterns of host abundance. Bacteria with streamlined genomes such as OM43 and the globally dominant SAR11 clade use riboswitches as an efficient method to regulate metabolism. Melnitz encodes a two-piece tmRNA (ssrA), controlled by a glutamine riboswitch, providing evidence that riboswitch use also occurs for regulation during phage infection of streamlined heterotrophs. Virally encoded tRNAs and ssrA found in Melnitz were phylogenetically more closely related to those found within the alphaproteobacterial SAR11 clade and their associated myophages than those within their gammaproteobacterial hosts. This suggests the possibility of an ancestral host transition event between SAR11 and OM43. Melnitz and a related myophage that infects SAR11 were unable to infect hosts of the SAR11 and OM43, respectively, suggesting host transition rather than a broadening of host range.IMPORTANCE Isolation and cultivation of viruses are the foundations on which the mechanistic understanding of virus-host interactions and parameterization of bioinformatic tools for viral ecology are based. This study isolated and characterized the first myophage known to infect the OM43 clade, expanding our knowledge of this understudied group of microbes. The nearly identical genomes of four strains of Melnitz isolated from different marine provinces and the global abundance estimations from metagenomic data suggest that this viral population is globally ubiquitous. Genome analysis revealed several unusual features in Melnitz and related genomes recovered from viromes, such as a curli operon and virally encoded tmRNA controlled by a glutamine riboswitch, neither of which are found in the host. Further phylogenetic analysis of shared genes indicates that this group of viruses infecting the gammaproteobacterial OM43 shares a recent common ancestor with viruses infecting the abundant alphaproteobacterial SAR11 clade. Host ranges are affected by compatible cell surface receptors, successful circumvention of superinfection exclusion systems, and the presence of required accessory proteins, which typically limits phages to singular narrow groups of closely related bacterial hosts. This study provides intriguing evidence that for streamlined heterotrophic bacteria, virus-host transitioning may not be necessarily restricted to phylogenetically related hosts but is a function of shared physical and biochemical properties of the cell.

Melatonin as a microenvironmental cue for parasite development inside the host

Throughout the evolutionary process, parasites have
 acquired characteristics that function as survival mechanisms. It has been
 reported that melatonin, a molecule present in virtually all living organisms,
 has several roles in parasite biology such as preventing tissue damage,
 regulating gene expression and inflammatory processes, and acting as a free
 radical scavenger. Additionally,
 melatonin produced by the hosts accelerates the intra-erythrocytic cycle of the
 human malaria parasite Plasmodium falciparum and the rodent malaria
 parasite P. chabaudi, respectively. These findings have recently led to
 an increased research enthusiasm to find how melatonin influences the
 biological cycle of parasites. Therefore, this review aims to gather and
 analyze the potential relationships of host produced melatonin with the
 parasites Plasmodium sp., Trypanosoma cruzi, Leishmania
 spp., Toxoplasma gondii, Schistosoma mansoni, Opisthorchis viverrini, and Entamoeba
 histolytica, respectively.

Finding the needle in the haystack: a revision of Crittendenia, a surprisingly diverse lichenicolous genus of Agaricostilbomycetes, Pucciniomycotina

While most lichenicolous fungi belong to the Ascomycota, c. 5% of them are members of the Basidiomycota. Among these, the poorly known genus Crittendenia in the Pucciniomycotina has recently been described for lichenicolous fungi with minuscule needle-like synnematous basidiomata. Although only two species were hitherto known, the wide observed host-spectrum suggested a larger number of mainly host-specific species. A classical revision using morphological characters alone proved to be virtually impossible, because of the large variability of the material from each host genus, and the scant morphological differences between hypothetically distinct species from different hosts. We studied over sixty specimens and made a large number of measurements of the available morphological characters. We additionally generated 18 ITS and 21 nuLSU rDNA sequences and conducted maximum likelihood and Bayesian analyses. We also performed one species delimitation analysis (bPTP-ML). By combining sometimes subtle morphological differences, host choice and phylogenetic results, we were able to accept eighteen morphologically and/or genetically distinct species, all confined to a single host genus or to several closely related host genera. Two further putative species are left unnamed, as richer material is needed and molecular data are missing. Sixteen new species are described: Crittendenia absistentis (on Bacidia absistens), C. bacidinae (on Bacidina apiahica), C. bryostigmatis (on Bryostigma muscigenum), C. byssolomatis (on Byssoloma maderense), C. crassitunicata (on Melanohalea ushuaiensis), C. heterodermiae (on Heterodermia comosa), C. hypotrachynae (on Hypotrachyna), C. kakouettae (on ‘Byssoloma’ kakouettae), C. lecanorae (on Lecanora), C. lecidellae (on Lecidella elaeochroma), C. lopadii (on Lopadium disciforme), C. parvispora (on Bacidia), C. physciiphila (on Phaeophyscia, Physcia and Physciella), C. physconiae (on Physconia distorta), C. stictae (on Sticta fuliginosa) and C. teloschistis (on Teloschistes). Further, a ML analysis of the Agaricostilbomycetes using ITS and nuLSU sequences suggested that Crittendenia cannot be included in any known family, and the new family Crittendeniaceae is therefore described for the genus.

Phylogenetic approach for identification and life cycles of Puccinia (Pucciniaceae) species on Carex (Cyperaceae) from northeastern China

About 150 species of Puccinia on Carex (Cyperaceae) have been reported globally. However, these species can be difficult to identify due to similarities in morphology and difficulties in identifying the host plants. The presence of many cryptic species is also suspected. Based on about 130 specimens on Carex and about 40 related specimens of spermogonial and aecial stages, all collected in northeastern China, a phylogenetic approach was conducted to clarify their identification and life cycles. In the phylogenetic analyses, 17 clades among specimens on Carex were detected. Each clade was interpreted as an independent species, although many clades were morphologically similar to each other. After comparative morphology with species previously reported, seven species including three first records in China (P. circaeae-caricis, P. urticae-inflatae and P. vaginatae) were identified, while ten species (P. caricis-artemisiae, P. caricis-atractylodes, P. caricis-hebeiensis, P. caricis-jilinensis, P. caricis-lactucae, P. caricis-pediformis, P. caricis-rafaensis, P. caricis-ribicola, P. caricis-tenuiformis and P. caricis-violae) are described as new. In uredinial and telial stages, many host plant species could not be identified as they lacked an inflorescence. Thus, a phylogenetic approach is more suitable for species identifications of Puccinia on Carex rather than relying on rust morphology and host plant identification. Life cycle relations for 12 spermogonial and aecial species were also clarified using phylogenetic analyses. Furthermore, it is suspected that Puccinia species on Carex can be differentiated into species based on their spermogonial and aecial stages on the same or related host plants. Additionally, one new replacement name (P. caricis-aphanolepidis) for P. pulchella is proposed.

The gut microbial metabolite formate exacerbates colorectal cancer progression

The gut microbiome is a key player in the immunomodulatory and protumorigenic microenvironment during colorectal cancer (CRC), as different gut-derived bacteria can induce tumour growth. However, the crosstalk between the gut microbiome and the host in relation to tumour cell metabolism remains largely unexplored. Here we show that formate, a metabolite produced by the CRC-associated bacterium Fusobacterium nucleatum, promotes CRC development. We describe molecular signatures linking CRC phenotypes with Fusobacterium abundance. Cocultures of F. nucleatum with patient-derived CRC cells display protumorigenic effects, along with a metabolic shift towards increased formate secretion and cancer glutamine metabolism. We further show that microbiome-derived formate drives CRC tumour invasion by triggering AhR signalling, while increasing cancer stemness. Finally, F. nucleatum or formate treatment in mice leads to increased tumour incidence or size, and Th17 cell expansion, which can favour proinflammatory profiles. Moving beyond observational studies, we identify formate as a gut-derived oncometabolite that is relevant for CRC progression.

Parasite-associated mortality in birds: the roles of specialist parasites and host evolutionary distance.

The factors that influence whether a parasite is likely to cause death in a given host species are not well known. Generalist parasites with high local abundances, broad distributions and the ability to infect a wide phylogenetic diversity of hosts are often considered especially dangerous for host populations, though comparatively little research has been done on the potential for specialist parasites to cause host mortality. Here, using a novel database of avian mortality records, we tested whether phylogenetic host specialist or host generalist haemosporidian blood parasites were associated with avian host deaths based on infection records from over 81 000 examined hosts. In support of the hypothesis that host specialist parasites can be highly virulent in novel hosts, we found that the parasites that were associated with avian host mortality predominantly infected more closely related host species than expected under a null model. Hosts that died tended to be distantly related to the host species that a parasite lineage typically infects, illustrating that specialist parasites can cause death outside of their limited host range. Overall, this study highlights the overlooked potential for host specialist parasites to cause host mortality despite their constrained ecological niches.

Nutrition Status of Refugee and Host-Country Children: Negotiating for Equal Distribution of Relief Food During Emergencies in Uganda.

About 25.4 million people worldwide are living as refugees of whom 1.36 million are in Uganda. The refugees in this study were from South Sudan. The objective of this study was to determine the nutrition status of the refugee children and elucidate the factors that contribute to poor nutrition status among the host. The study used comparative analytical cross-sectional design on 340 children aged 6-59months. The overall prevalence of global acute malnutrition was 3.9%, underweight 14.1%, and stunting 24.7%. Five factors contributed to poor nutrition status; household size (ORa 1.34, 1.92), illness in wasted, stunted and underweight (ORa 1.47, 1.49, 1.97) children, being a host in relation to wasting and stunting (ORa 1.81, 1.36) and deworming (ORa 3.2, 2.13). Although the host had good nutrient intake, the refugee children had better nutrition status. Therefore, the Uganda government should formulate a policy that allows the host to benefit equally from food relief during emergencies.

Predicting Blood Parasite Load and Influence of Expression of iNOS on the Effect Size of Clinical Laboratory Parameters in Acute Trypanosoma cruzi Infection With Different Inoculum Concentrations in C57BL/6 Mice.

In Chagas disease, the initial responses of phagocyte-mediated innate immunity are strongly associated with the control of Trypanosoma cruzi and are mediated by various signaling pathways, including the inducible nitric oxide synthetase (iNOS) pathway. The clinical and laboratory manifestations of Chagas disease depend on the parasite–host relationship, i.e., the responsive capacity of the host immune system and the immunogenicity of the parasite. Here, we evaluated effect sizes in clinical and laboratory parameters mediated by acute infection with different concentrations of T. cruzi inoculum in mice immunosuppressed via iNOS pathway inactivation. Infection was induced in C57BL/6 wild-type and iNOS-/- mice with the “Y” strain of T. cruzi at three inoculum concentrations (3 × 102, 3 × 103, and 3 × 104). Parasitemia and mortality in both mouse strains were monitored. Immunohistochemistry was performed to quantify amastigotes in cardiac tissues and cardiac musculature cells. Biochemical parameters, such as blood urea nitrogen, sodium, albumin, and globulin concentrations, among others, were measured, and cytokine concentrations were also measured. Effect sizes were determined by the eta squared formula. Compared with that in wild-type animals, mice with an absence of iNOS expression demonstrated a greater parasite load, with earlier infection and a delayed parasitemia peak. Inoculum concentration was positively related to death in the immunosuppressed subgroup. Nineteen parameters (hematological, biochemical, cytokine-related, and histopathological) in the immunocompetent subgroup and four in the immunosuppressed subgroup were associated with parasitemia. Parasitemia, biochemical parameters, and hematological parameters were found to be predictors in the knockout group. The impact of effect sizes on the markers evaluated based on T. cruzi inoculum concentration was notably high in the immunocompetent group (Cohen’s d = 88.50%; p <.001). These findings contribute to the understanding of physiopathogenic mechanisms underlying T. cruzi infection and also indicate the influence of the concentration of T. cruzi during infection and the immunosuppression through the iNOS pathway in clinical laboratory heterogeneity reported in acute Chagas disease.

Host and Tissue Affiliations of Culturable Endophytic Fungi Associated with Xerophytic Plants in the Desert Region of Northwest China

Endophytic fungi isolated from plants under drought stress have been evidenced to confer hosts adaptive benefits to withstand drought. In this study, endophytic fungi associated with five typical desert shrubs in different tissue from extremely arid desert in Northwest China were investigated based on ITS sequence analysis. A total of 158 endophytic fungal stains were isolated from 1088 tissue segments of 12 samples, and 28 taxa represented by 25 species and 15 genera were identified as Ascomycetes. Alternaria sp. was the dominant genus with generic abundance ranging from 20% to 65%. The colonization rate of root was significantly lower, but the root-endophytic fungi (19 species) conversely presented a higher diversity than stem and leaf (11 and 7 species, respectively). Endophytic fungi had pronounced relative host and tissue preferences, while tissue explained more endophytic fungal variation than plant species. Additionally, soil pH, organic carbon, and phosphatase elicited significant responses from fungal species, which significantly affected the species richness of Fusarium redolens, Alternaria chlamydospore, Didymella glomerata, and Xylariales sp. This research provides a basis for the further understanding of the ecological distribution of endophytic fungi associated with xerophytic plants and their potential application for vegetative restoration and agricultural cultivation in drylands.

Unbridled Integrons: A Matter of Host Factors.

Integrons are powerful recombination systems found in bacteria, which act as platforms capable of capturing, stockpiling, excising and reordering mobile elements called cassettes. These dynamic genetic machineries confer a very high potential of adaptation to their host and have quickly found themselves at the forefront of antibiotic resistance, allowing for the quick emergence of multi-resistant phenotypes in a wide range of bacterial species. Part of the success of the integron is explained by its ability to integrate various environmental and biological signals in order to allow the host to respond to these optimally. In this review, we highlight the substantial interconnectivity that exists between integrons and their hosts and its importance to face changing environments. We list the factors influencing the expression of the cassettes, the expression of the integrase, and the various recombination reactions catalyzed by the integrase. The combination of all these host factors allows for a very tight regulation of the system at the cost of a limited ability to spread by horizontal gene transfer and function in remotely related hosts. Hence, we underline the important consequences these factors have on the evolution of integrons. Indeed, we propose that sedentary chromosomal integrons that were less connected or connected via more universal factors are those that have been more successful upon mobilization in mobile genetic structures, in contrast to those that were connected to species-specific host factors. Thus, the level of specificity of the involved host factors network may have been decisive for the transition from chromosomal integrons to the mobile integrons, which are now widespread. As such, integrons represent a perfect example of the conflicting relationship between the ability to control a biological system and its potential for transferability.

ТИПИЗАЦИЯ ОЧАГОВ ВИСЦЕРАЛЬНОГО ЛЕЙШМАНИОЗА В ЕВРОПЕЙСКОМ РЕГИОНЕ ВОЗ

Based on the analysis of various variants of the composition of the parasitic system of visceral leishmaniasis in the who European region, the typification of foci is proposed depending on the nature of the relationship of vertebrate hosts of Leishmania with humans, the number of vectors, the intensity of the epidemic manifestation and its relevance to certain landscapes. The composition of the vectors of VL foci are divided into monofactorial and polypectomy; participation as a reservoir of different mammals to natural and synanthropic, on monogotari and oligosaline. According to the intensity of the epidemic manifestation, foci are ranked into hyperendemic, mesoendemic and hypoendemic. The most favorable landscapes for the existence of the parasitic system of visceral leishmaniasis are the territories occupied by savannas, woodlands, Mediterranean dry forests and shrubs. Preventive measures in the foci of visceral leishmaniasis should be carried out differentially, depending on the belonging of foci to a certain rank. Key words: leishmaniasis, visceral, hearth, natural, synanthropic, typification, carrier, reservoir, landscape

The dynamic landscape of parasitemia dependent intestinal microbiota shifting and the correlated gut transcriptome during Plasmodium yoelii infection

Malaria, caused by Plasmodium, is a global life-threatening infectious disease. However, the dynamic interactions between intestinal microbiota and host immunity during the infections are still unclear. Here, we investigated the change of intestinal microbiome and transcriptome during Plasmodium yoelii infection in mice. The mice were infected with P. yoelii through the intraperitoneal injection. The intestinal contents and tissues were collected at different time points along with the malaria procession and they were subjected to the microbiome and transcriptome sequencing and analysis respectively. The dynamic landscape of parasitemia-dependent intestinal microbiota and related host immunity were identified: (1) The diversity and composition of the intestinal microbiota represented a significant correlation with the Plasmodium infection; (2) Up-regulated genes from the intestinal transcriptome were mainly enriched in immune cell differentiation pathways, especially, naive CD4+ T cell differentiation to Th1/2 cells in the early immune response and Th17 cells in the later immune stage, T cell receptor (TCR) and B cell receptor (BCR) activation in the whole host immunity; (3) Host immune cells presented parasitemia phase-specific characteristics against P. yoelii infection; (4) There were significant associations between the parasitemia phase-specific microbiotas and the host immune response. Th1 cell differentiation was positively correlated with genera Moryella and specie Erysipelotrichaceae bacterium canine oral taxon 255, while negatively correlated with genera Ruminiclostridium. Th17 cell differentiation was related to the colonization of family Peptococcaceae, genera Lachnospiraceae FCS020 group, and specie Eubacterium plexicaudatum ASF492 and the reduction of family Bacteroidales BS11 gut group, genera Sutterella, and specie Parabacteroides distasonis str. 3776 D15 I. BCRs and TCRs were highly related with the family Bacteroidales BS11 gut group, genera Moryella, and specie Erysipelotrichaceae bacterium canine oral taxon 255, but negatively related with the genera Ruminiclostridium. Our results indicated a remarkable dynamic landscape and correlation of the parasitemia-dependent shifting of intestinal microbiota and immunity, suggesting the essential roles of intestinal microbiome on the modulation of host immunity against Plasmodium infection.

The Neglected Virome of Triatomine Insects

The Triatominae subfamily (Reduviidae) harbors some hematophagous insect species that have been firmly connected to the transmission of Trypanosoma cruzi, the causative agent of Chagas disease. Triatomines not only host and transmit trypanosomatids, but also coexist with a variety of symbiotic microorganisms that generally reside in the insect’s intestinal flora. The microbiome has profound effects on the physiology, immunity, fitness and survival of animals and plants. The interaction between triatomines and bacteria has been investigated to some extent and has revealed important bacteria symbionts. In contrast, the range of viral species that can infect triatomine insects is almost completely unknown. In some cases, genomic and metatranscriptomic approaches have uncovered sequences related to possible viral genomes, but, to date, only eight positive single-strand RNA viruses, namely Triatoma virus and Rhodnius prolixus viruses 1 - 7 have been investigated in more detail. Here, we review the literature available on triatomine viruses and the viruses-insect host relationship. The lack of broader metagenomic and metatranscriptomic studies in these medically relevant insects underscores the importance of expanding our knowledge of the triatomine virome both for surveillance purposes as well as to possibly harness their potential for insect vector population control strategies.

Phylogenetic approach for identification and life cycles of Puccinia (Pucciniaceae) species on Poaceae from northeastern China

About 300 species of Puccinia on Poaceae have been reported globally. However, these species can be difficult to identify because of morphological similarities and difficulties of host plant identifications. The presence of many cryptic species is also suspected. Based on about 150 specimens on Poaceae and about 50 related specimens of spermogonial and aecial stages, all collected in northeastern China, a phylogenetic approach was conducted to clarify their identification and life cycles. In phylogenetic analyses 25 clades among specimens on Poaceae were detected. Each clade detected in phylogeny was interpreted as an independent species, although many clades were morphologically similar to each other. After comparative morphology with species previously reported, 17 species including three first records in China (P. cerienthes-agropyrina, P. coronati-agrostidis, P. coronati-hordei) were identified, and eight species (P. ampliaticoronata, P. digitaticoronata, P. eleganticoronata, P. elymi-albispora, P. oncospora, P. pileiformis, P. protuberanticoronata, P. ramificatacoronata) are described as new. In uredinial and telial stages, the host range of above 25 species was variable ranging from one host plant species to several host species, sometimes involving different grass genera. Thus, a phylogenetic approach is more suitable for species identifications of Puccinia on Poaceae rather than relying on rust morphology and host plant identification. Life cycle relations for 15 spermogonial and aecial species were also clarified by phylogenetic analyses. It is also suspected that grass rusts can be differentiated to species based on spermogonial and aecial stages on same or related host plants.

Inter- and Intrasexual Variation in Cuticular Hydrocarbons in Trichrysis cyanea (Linnaeus, 1758) (Hymenoptera: Chrysididae).

Simple SummaryThe biology of many species of cuckoo wasps (Chrysididae) is largely unknown, except for, if at all, the host species of these brood parasites. Cuticular hydrocarbons (CHCs), which form a waxy layer on the body surface of insects, have been shown to be mimicked by host-specific cuckoo wasp species. We studied the CHC profiles of a rather generalist brood parasitic cuckoo wasp species, Trichrysis cyanea, in detail. We found sex-related differences in CHCs and three different chemotypes among females. Genetic data reject the possibility that these different chemotypes represent different (cryptic) species. The CHC polymorphism could be an adaptation for females to sneak into nesting holes of hosts with the different female chemotypes representing adaptations to a broader host range. However, since information on the CHC profiles of the hosts is missing, it remains unclear whether these different CHC profiles are used for chemical mimicry or are simply age-related, reflecting the females’ reproductive state. Cuckoo wasps (Chrysididae, Hymenoptera) are known for their parasitoid or cleptoparasitic life histories. Indeed, the biology of only a few species has been studied in detail and often only little more is known than the host species. By mimicking their hosts’ cuticular hydrocarbon (CHC) profiles, species that parasitize single (or a few closely related) host species manage to deceive their hosts. However, the variability of the CHC profile in generalist cuckoo-wasp species is still unknown. Here, we used gas chromatography—mass spectrometry (GC-MS) and DNA barcoding to study intraspecific variation in cuticular hydrocarbons of one less host-specific species of cuckoo wasps, Trichrysis cyanea. Cuticular hydrocarbon (CHC) patterns were found to differ between males and females. Additionally, we found chemical polymorphism among females, which formed three distinct chemical subgroups characterized by different alkene patterns. A lack of divergence in the DNA barcoding region suggests that these different chemotypes do not represent cryptic species. Whether this intrasexual CHC-profile variation is an adaptation (mimicry) to different host species, or simply signaling the reproductive status, remains unclear.

Evidence of a Possible Viral Host Switch Event in an Avipoxvirus Isolated from an Endangered Northern Royal Albatross (Diomedea sanfordi).

Avipoxviruses have been characterized from many avian species. Two recent studies have reported avipoxvirus-like viruses with varying pathogenicity in reptiles. Avipoxviruses are considered to be restricted to avian hosts. However, reports of avipoxvirus-like viruses from reptiles such as the green sea turtle (Chelonia mydas) and crocodile tegu (Crocodilurus amazonicus) suggest that cross-species transmission, within avian species and beyond, may be possible. Here we report evidence for a possible host switching event with a fowlpox-like virus recovered from an endangered northern royal albatross (Diomodea sanfordi)—a species of Procellariiformes, unrelated to Galliformes, not previously known to have been infected with fowlpox-like viruses. Complete genome sequencing of this virus, tentatively designated albatrosspox virus 2 (ALPV2), contained many fowlpox virus-like genes, but also 63 unique genes that are not reported in any other poxvirus. The ALPV2 genome contained 296 predicted genes homologous to different avipoxviruses, 260 of which were homologous to an American strain of fowlpox virus (FWPV). Subsequent phylogenetic analyses indicate that ALPV2 likely originated from a fowlpox virus-like progenitor. These findings highlight the importance of host-switching events where viruses cross species barriers with the risk of disease in close and distantly related host populations.