Putative Type Research Articles

Expansion Properties of the Young Supernova Type Iax Remnant Pa 30 Revealed

The recently discovered Pa 30 nebula, the putative type Iax supernova remnant associated with the historical supernova of 1181 AD, shows puzzling characteristics that make it unique among known supernova remnants. In particular, Pa 30 exhibits a complex morphology, with a unique radial and filamentary structure, and it hosts a hot stellar remnant at its center, which displays oxygen-dominated, ultrafast winds. Because of the surviving stellar remnant and the lack of hydrogen and helium in its filaments, it has been suggested that Pa 30 is the product of a failed thermonuclear explosion in a near- or super-Chandrasekhar white dwarf, which created a subluminous transient, a rare subtype of the Ia class of supernovae called type Iax. We present here a detailed study of the 3D structure and velocities of a full radial section of the remnant. The Integral Field Unit observations, obtained with the new red channel of the Keck Cosmic Web Imager spectrograph, reveal that the ejecta are consistent with being ballistic, with velocities close to the free-expansion velocity. Additionally, we detect a large cavity inside the supernova remnant and a sharp inner edge to the filamentary structure, which coincides with the outer edge of a bright ring detected in infrared images. Finally, we detect a strong asymmetry in the amount of ejecta along the line of sight, which might hint at an asymmetric explosion. Our analysis provides strong confirmation that the explosion originated from SN 1181.

The putative type 4 secretion system effector BspD is involved in maintaining envelope integrity of the pathogen Brucella.

Brucellosis, caused by the intracellular pathogen Brucella, poses a significant health threat. Understanding how Brucella adapts to stressful environments is crucial. This study unveils BspD, a conserved protein within the Rhizobiales order, as a key player in maintaining Brucella's envelope integrity. Remarkably, BspD's presence within the Rizobiales appears independent of the presence of a T4SS or a specific lifestyle. Deletion of bspD resulted in compromised envelope integrity, abnormal bacterial morphologies, and reduced intracellular microcolony formation. These findings underscore BspD's critical role, particularly in stressful conditions like the stationary phase and EDTA exposure, and highlight its significance for the survival of Brucella within host cells. This elucidation deepens our understanding of Brucella pathogenesis and may inform future therapeutic strategies against brucellosis.

CT584 Is Not a Protective Vaccine Antigen against Respiratory Chlamydial Challenge in Mice.

Background:Chlamydia trachomatis is the most prevalent bacterial sexually transmitted pathogen in humans worldwide. Since chlamydial infection is largely asymptomatic with the potential for serious complications, a preventative vaccine is likely the most viable long-term answer to this public health threat. Cell-free protein synthesis (CFPS) utilizes the cellular protein manufacturing machinery decoupled from the requirement for maintaining cellular viability, offering the potential for flexible, rapid, and decentralized production of recombinant protein vaccine antigens. Methods: Here, we use CFPS to produce the full-length putative chlamydial type three secretion system (T3SS) needle-tip protein, CT584, for evaluation as a vaccine antigen in mouse models. High-speed atomic force microscopy (HS-AFM) (RIBM, Tsukuba, Japan) imaging and computer simulations confirm that CFPS-produced CT584 retains a native-like structure prior to immunization. Female mice were primed with CT584 adjuvanted with CpG-1826 intranasally (i.n.) or CpG-1826 + Montanide ISA 720 intramuscularly (i.m.), followed four weeks later by an i.m. boost before respiratory challenge with 104 inclusion forming units (IFU) of Chlamydia muridarum. Results: Immunization with CT584 generated robust antibody responses but weak cell-mediated immunity and failed to protect against i.n. challenge as demonstrated by body weight loss, increased lung weights, and the presence of high numbers of IFUs in the lungs. Conclusion: While CT584 was not a protective vaccine candidate, the speed and flexibility with which CFPS can be used to produce other potential chlamydial antigens make it an attractive technique for antigen production.

Evolution of unexpected diversity in a putative mating type locus and its correlation with genome variability reveals likely asexuality in the model mycorrhizal fungus Rhizophagus irregularis

BackgroundArbuscular mycorrhizal fungi (AMF) form mutualistic partnerships with approximately 80% of plant species. AMF, and their diversity, play a fundamental role in plant growth, driving plant diversity, and global carbon cycles. Knowing whether AMF are sexual or asexual has fundamental consequences for how they can be used in agricultural applications. Evidence for and against sexuality in the model AMF, Rhizophagus irregularis, has been proposed. The discovery of a putative mating-type locus (MAT locus) in R. irregularis, and the previously suggested recombination among nuclei of a dikaryon R. irregularis isolate, potentially suggested sexuality. Unless undergoing frequent sexual reproduction, evolution of MAT-locus diversity is expected to be very low. Additionally, in sexual species, MAT-locus evolution is decoupled from the evolution of arbitrary genome-wide loci.ResultsWe studied MAT-locus diversity of R. irregularis. This was then compared to diversification in a phosphate transporter gene (PTG), that is not involved in sex, and to genome-wide divergence, defined by 47,378 single nucleotide polymorphisms. Strikingly, we found unexpectedly high MAT-locus diversity indicating that either it is not involved in sex, or that AMF are highly active in sex. However, a strongly congruent evolutionary history of the MAT-locus, PTG and genome-wide arbitrary loci allows us to reject both the hypothesis that the MAT-locus is involved in mating and that the R. irregularis lineage is sexual.ConclusionOur finding shapes the approach to developing more effective AMF strains and is highly informative as it suggests that introduced strains applied in agriculture will not exchange DNA with native populations.

New Viruses Infecting Hyperthermophilic Bacterium Thermus thermophilus.

Highly diverse phages infecting thermophilic bacteria of the Thermus genus have been isolated over the years from hot springs around the world. Many of these phages are unique, rely on highly unusual developmental strategies, and encode novel enzymes. The variety of Thermus phages is clearly undersampled, as evidenced, for example, by a paucity of phage-matching spacers in Thermus CRISPR arrays. Using water samples collected from hot springs in the Kunashir Island from the Kuril archipelago and from the Tsaishi and Nokalakevi districts in the Republic of Georgia, we isolated several distinct phages infecting laboratory strains of Thermus thermophilus. Genomic sequence analysis of 11 phages revealed both close relatives of previously described Thermus phages isolated from geographically distant sites, as well as phages with very limited similarity to earlier isolates. Comparative analysis allowed us to predict several accessory phage genes whose products may be involved in host defense/interviral warfare, including a putative Type V CRISPR-cas system.

Metabotropic Glutamate Receptors Type 3 and 5 Feature the "NeuroTransmitter-type" of Glioblastoma: A Bioinformatic Approach.

Glioblastoma (GBM) represents an aggressive and common tumor of the central nervous system. The prognosis of GBM is poor, and despite a refined genetic and molecular characterization, pharmacological treatment is largely suboptimal. Contribute to defining a therapeutic line in GBM targeting the mGlu3 receptor in line with the principles of precision medicine. Here, we performed a computational analysis focused on the expression of type 3 and 5 metabotropic glutamate receptor subtypes (mGlu3 and mGlu5, respectively) in high- and low-grade gliomas. The analysis allowed the identification of a particular high-grade glioma type, characterized by a high expression level of both receptor subtypes and by other markers of excitatory and inhibitory neurotransmission. This so-called neurotransmitter-GBM (NT-GBM) also shows a distinct immunological, metabolic, and vascularization gene signature. Our findings might lay the groundwork for a targeted therapy to be specifically applied to this putative novel type of GBM.

Type I arginine methyltransferases play crucial roles in development and pathogenesis of Phytophthora capsici

Phytophthora capsici, a pathogenic oomycete, poses a serious threat to global vegetable production. This study investigated the role of protein arginine methylation, a notable post-translational modification, in the epigenetic regulation of P. capsici. We identified and characterized five protein arginine methyltransferases (PRMTs) in P. capsici, with a focus on four putative type I PRMTs exhibiting similar functional domain. Deletion of PcPRMT3, a homolog of PRMT3, significantly affected mycelial growth, asexual spore development, pathogenicity, and stress responses in P. capsici. Transcriptome analyses indicated that absence of PcPRMT3 disrupted multiple biological pathways. The PcPRMT3 deletion mutant displayed heightened susceptibility to oxidative stress, correlated with the downregulation of genes involved in peroxidase and peroxisome activities. Additionally, PcPRMT3 acted as a negative regulator, modulating the transcription levels of specific elicitins, which in turn affects the defense response of host plant against P. capsici. Furthermore, PcPRMT3 was found to affect global arginine methylation levels in P. capsici, implying potential alterations in the functions of its substrate proteins.

The Restriction Activity Investigation of Rv2528c, an Mrr-like Modification-Dependent Restriction Endonuclease from Mycobacterium tuberculosis.

Mycobacterium tuberculosis (Mtb), as a typical intracellular pathogen, possesses several putative restriction-modification (R-M) systems, which restrict exogenous DNA's entry, such as bacterial phage infection. Here, we investigate Rv2528c, a putative Mrr-like type IV restriction endonuclease (REase) from Mtb H37Rv, which is predicted to degrade methylated DNA that contains m6A, m5C, etc. Rv2528c shows significant cytotoxicity after being expressed in Escherichia coli BL21(DE3)pLysS strain. The Terminal deoxynucleotidyl transferase dUTP Nick-End Labeling (TUNEL) assay indicates that Rv2528c cleaves genomic DNA in vivo. The plasmid transformation efficiency of BL21(DE3)pLysS strain harboring Rv2528c gene was obviously decreased after plasmids were in vitro methylated by commercial DNA methyltransferases such as M.EcoGII, M.HhaI, etc. These results are consistent with the characteristics of type IV REases. The in vitro DNA cleavage condition and the consensus cleavage/recognition site of Rv2528c still remain unclear, similar to that of most Mrr-family proteins. The possible reasons mentioned above and the potential role of Rv2528c for Mtb were discussed.

Evaluation in mice of cell-free produced CT584 as a Chlamydia vaccine antigen.

Chlamydia trachomatis is the most prevalent bacterial sexually transmitted pathogen worldwide. Since chlamydial infection is largely asymptomatic with the potential for serious complications, a preventative vaccine is likely the most viable long-term answer to this public health threat. Cell-free protein synthesis (CFPS) utilizes the cellular protein manufacturing machinery decoupled from the requirement for maintaining cellular viability, offering the potential for flexible, rapid, and de-centralized production of recombinant protein vaccine antigens. Here, we use CFPS to produce the putative chlamydial type three secretion system (T3SS) needle-tip protein, CT584, for use as a vaccine antigen in mouse models. High-speed atomic force microscopy (HS-AFM) imaging and computer simulations confirm that CFPS-produced CT584 retains a native-like structure prior to immunization. Female mice were primed with CT584 adjuvanted with CpG-1826 intranasally (i.n.) or CpG-1826 + Montanide ISA 720 intramuscularly (i.m.), followed four-weeks later by an i.m. boost before respiratory challenge with 104 inclusion forming units (IFU) of Chlamydia muridarum. Immunization with CT584 generated robust antibody responses but weak cell mediated immunity and failed to protect against i.n. challenge as demonstrated by body weight loss, increased lungs' weights and the presence of high numbers of IFUs in the lungs. While CT584 alone may not be the ideal vaccine candidate, the speed and flexibility with which CFPS can be used to produce other potential chlamydial antigens makes it an attractive technique for antigen production.

An appraisal of the Mozambique types and endemic taxa in the Pires de Lima plant collection at the Porto Herbarium (PO, MHNC-UP)

Putative type specimens of 18 taxa described from Mozambique collected by Américo Pires de Lima at the beginning of the 20th century are kept in the African collections of the Herbarium of Porto (PO) at the MHNC-UP. These specimens were not collected as part of a dedicated scientific mission, but they and the scientific studies carried out by Pires de Lima represent an important contribution to Portuguese colonial projects. During his scientific career, and despite the lack of support and specialised literature, Pires de Lima described 17 species new to science. In this work we analysed part of the material collected by Pires de Lima, kept in PO at MHNC-UP. Today, only two of the 17 taxa described by Pires de Lima remain as accepted taxa, viz. Tephrosia reptans var. microfoliata (Pires de Lima) Brummitt and Crotalaria retusa var. tunguensis (Pires de Lima) Polhill. In addition, information on Polygala limae Exell, named after Pires de Lima, has also been analysed as this is still accepted. Of over 300 specimens collected by Pires de Lima in the early 20th century, some 40% remain unidentified due to lack of expertise. Undoubtedly, this collection contains many other promising specimens in need of revision, taxonomic update, and other novelties that can be found even in the more ancient and inconspicuous materials.

Bioinformatics analysis of type II toxin-antitoxin systems and regulatory functional assessment of HigBA and SS-ATA in Streptococcus suis1

Toxin-antitoxin (TA) systems, which are prevalent in bacteria and archaea, play diverse roles in bacterial physiology and have been proposed to be significant in stress adaptation. Despite the extensive characterization of numerous TA systems in various bacteria, the investigation of these systems within Streptococcus suis (S. suis) is still limited. Here, we systematically analyzed the type II TA systems of 95 S. suis genomes available in the GenBank database using TAfinder. A total of 612 putative type II TA systems were retrieved and classified into 10 categories by phylogenetic analysis. Notably, an elevated occurrence of these TA systems was observed among the important prevalent serotypes 2, 4, 5, 9, 14, Chz, NCL1, and NCL3 strains. The following study identified the activities of TA systems using two strategies and confirmed the regulatory effect of HigBA on the type VII secretion system in S. suis by measuring β-galactosidase activity and transcriptional changes. Moreover, we unveiled a hitherto uncharacterized, highly prevalent novel TA system, with the composition of antitoxin-toxin-antitoxin (SS-ATA), which regulates the downstream two-component signaling system. Altogether, this study systematically analyzed the type II TA systems within S. suis, highlighting the widespread distribution of HigBA and SS-ATA as important regulatory elements in S. suis.

Association of SLC6A3 variants with treatment-resistant schizophrenia: a genetic association study of dopamine-related genes in schizophrenia.

Most genetic analyses that have attempted to identify a locus or loci that can distinguish patients with treatment-resistant schizophrenia (TRS) from those who respond to treatment (non-TRS) have failed. However, evidence from multiple studies suggests that patients with schizophrenia who respond well to antipsychotic medication have a higher dopamine (DA) state in brain synaptic clefts whereas patients with TRS do not show enhanced DA synthesis/release pathways. To examine the contribution (if any) of genetics to TRS, we conducted a genetic association analysis of DA-related genes in schizophrenia patients (TRS, n = 435; non-TRS, n = 539) and healthy controls (HC: n = 489). The distributions of the genotypes of rs3756450 and the 40-bp variable number tandem repeat on SLC6A3 differed between the TRS and non-TRS groups. Regarding rs3756450, the TRS group showed a significantly higher ratio of the A allele, whereas the non-TRS group predominantly had the G allele. The analysis of the combination of COMT and SLC6A3 yielded a significantly higher ratio of the putative low-DA type (i.e., high COMT activity + high SLC6A3 activity) in the TRS group compared to the two other groups. Patients with the low-DA type accounted for the minority of the non-TRS group and exhibited milder psychopathology. The overall results suggest that (i) SLC6A3 could be involved in responsiveness to antipsychotic medication and (ii) genetic variants modulating brain DA levels may be related to the classification of TRS and non-TRS.

A type III polyketide synthase cluster in the phylum Planctomycetota is involved in alkylresorcinol biosynthesis

Members of the bacterial phylum Planctomycetota have recently emerged as promising and for the most part untapped sources of novel bioactive compounds. The characterization of more than 100 novel species in the last decade stimulated recent bioprospection studies that start to unveil the chemical repertoire of the phylum. In this study, we performed systematic bioinformatic analyses based on the genomes of all 131 described members of the current phylum focusing on the identification of type III polyketide synthase (PKS) genes. Type III PKSs are versatile enzymes involved in the biosynthesis of a wide array of structurally diverse natural products with potent biological activities. We identified 96 putative type III PKS genes of which 58 are encoded in an operon with genes encoding a putative oxidoreductase and a methyltransferase. Sequence similarities on protein level and the genetic organization of the operon point towards a functional link to the structurally related hierridins recently discovered in picocyanobacteria. The heterologous expression of planctomycetal type III PKS genes from strains belonging to different families in an engineered Corynebacterium glutamicum strain led to the biosynthesis of pentadecyl- and heptadecylresorcinols. Phenotypic assays performed with the heterologous producer strains and a constructed type III PKS gene deletion mutant suggest that the natural function of the identified compounds differs from that confirmed in other bacterial alkylresorcinol producers.Key points• Planctomycetal type III polyketide synthases synthesize long-chain alkylresorcinols.• Phylogenetic analyses suggest an ecological link to picocyanobacterial hierridins.• Engineered C. glutamicum is suitable for an expression of planctomycete-derived genes.

Identification and evaluation of putative type 2 diabetes mellitus inhibitors derived from Cichorium intybus

Diabetes, triggered by impaired glucose regulation, is characterized by the conversion of glucose to sorbitol by aldose reductase (AR). In prior studies to develop AR inhibitors, the toxicity and efficacy of the therapeutic molecules presented challenges throughout clinical trials. This led the researchers to investigate the potential biological modulation of natural products owing to their varied chemical structures. Cichorium intybus L. (C. intybus), commonly known as chicory, has a long history of medicinal use and shows potential pharmacological properties, particularly in reducing lipid levels. The study employs computational methods, including ADMET profiling, molecular docking, and molecular dynamics (MD) simulation, to discover possible inhibitors of ALR-2 from C. intybus. The ADMET-filtered compounds from C. intybus show high binding energy viz, CID 8468: -133.295,370: -118.633, -109.479, and 359: -108.48 Kcal/mol. These compounds were observed to exhibit strong affinity and specificity for ALR-2 as comparable to epalrestat. MD simulation of the compounds 8468 and 370 for 100 ns, further authenticated the stability of their complexes with ALR2. The RMSD, RMSF, and intra-molecular interactions of the compounds were comparable to the native ligand-epalrestat, suggesting their potential to be considered as ALR2 inhibitors. Additional research including in vitro, in vivo analysis, and clinical trials is essential to accurately assess the efficacy of natural compounds.

In-depth transcriptomic analysis of Anopheles gambiae hemocytes uncovers novel genes and the oenocytoid developmental lineage

BackgroundHemocytes are immune cells that patrol the mosquito hemocoel and mediate critical cellular defense responses against pathogens. However, despite their importance, a comprehensive transcriptome of these cells was lacking because they constitute a very small fraction of the total cells in the insect, limiting the study of hemocyte differentiation and immune function.ResultsIn this study, an in-depth hemocyte transcriptome was built by extensive bulk RNA sequencing and assembly of hemocyte RNAs from adult A. gambiae female mosquitoes, based on approximately 2.4 billion short Illumina and about 9.4 million long PacBio high-quality reads that mapped to the A. gambiae PEST genome (P4.14 version). A total of 34,939 transcripts were annotated including 4,020 transcripts from novel genes and 20,008 novel isoforms that result from extensive differential splicing of transcripts from previously annotated genes. Most hemocyte transcripts identified (89.8%) are protein-coding while 10.2% are non-coding RNAs. The number of transcripts identified in the novel hemocyte transcriptome is twice the number in the current annotation of the A. gambiae genome (P4.14 version). Furthermore, we were able to refine the analysis of a previously published single-cell transcriptome (scRNAseq) data set by using the novel hemocyte transcriptome as a reference to re-define the hemocyte clusters and determine the path of hemocyte differentiation. Unsupervised pseudo-temporal ordering using the Tools for Single Cell Analysis software uncovered a novel putative prohemocyte precursor cell type that gives rise to prohemocytes. Pseudo-temporal ordering with the Monocle 3 software, which analyses changes in gene expression during dynamic biological processes, determined that oenocytoids derive from prohemocytes, a cell population that also gives rise to the granulocyte lineage.ConclusionA high number of mRNA splice variants are expressed in hemocytes, and they may account for the plasticity required to mount efficient responses to many different pathogens. This study highlights the importance of a comprehensive set of reference transcripts to perform robust single-cell transcriptomic data analysis of cells present in low abundance. The detailed annotation of the hemocyte transcriptome will uncover new facets of hemocyte development and function in adult dipterans and is a valuable community resource for future studies on mosquito cellular immunity.

Molecular mechanisms and environmental adaptations of flagellar loss and biofilm growth of Rhodanobacter under environmental stress.

Biofilms aid bacterial adhesion to surfaces via direct and indirect mechanisms, and formation of biofilms is considered as an important strategy for adaptation and survival in suboptimal environmental conditions. However, the molecular underpinnings of biofilm formation in subsurface sediment/groundwater ecosystems where microorganisms often experience fluctuations in nutrient input, pH, and nitrate or metal concentrations are underexplored. We examined biofilm formation under different nutrient, pH, metal, and nitrate regimens of 16 Rhodanobacter strains isolated from subsurface groundwater wells spanning diverse levels of pH (3.5 to 5) and nitrates (13.7 to 146mM). Eight Rhodanobacter strains demonstrated significant biofilm growth under low pH, suggesting adaptations for survival and growth at low pH. Biofilms were intensified under aluminum stress, particularly in strains possessing fewer genetic traits associated with biofilm formation, findings warranting further investigation. Through random barcode transposon-site sequencing (RB-TnSeq), proteomics, use of specific mutants, and transmission electron microscopy analysis, we discovered flagellar loss under aluminum stress, indicating a potential relationship between motility, metal tolerance, and biofilm growth. Comparative genomic analyses revealed the absence of flagella and chemotaxis genes and the presence of a putative type VI secretion system in the highly biofilm-forming strain FW021-MT20. In this study we identified genetic determinants associated with biofilm growth under metal stress in a predominant environmental genus, Rhodanobacter, and identified traits aiding survival and adaptation to contaminated subsurface environments.

A recently collected Xanthomonas translucens isolate encodes TAL effectors distinct from older, less virulent isolates.

Xanthomonas translucens, the causal agent of bacterial leaf streak disease (BLS) in cereals, is a re-emerging pathogen that is becoming increasingly destructive across the world. While BLS has caused yield losses in the past, there is anecdotal evidence that newer isolates may be more virulent. We observed that two X. translucens isolates collected from two sites in Colorado, USA, are more aggressive on current wheat and barley varieties compared to older isolates, and we hypothesize that genetic changes between recent and older isolates contribute to the differences in isolate aggressiveness. To test this, we phenotyped and genetically characterized two X. translucens isolates collected from Colorado in 2018, which we designated CO236 (from barley) and CO237 (from wheat). Using pathovar-specific phenotyping and PCR primers, we determined that CO236 belongs to pathovar translucens (Xtt) and CO237 belongs to pathovar undulosa (Xtu). We sequenced the full genomes of the isolates using Oxford Nanopore long-read sequencing, and compared their whole genomes against published X. translucens genomes. This analysis confirmed our pathovar designations for Xtt CO236 and Xtu CO237, and showed that, at the whole-genome level, there were no obvious genomic structural changes between Xtt CO236 and Xtu CO237 and other respective published pathovar genomes. Focusing on pathovar undulosa (Xtu CO237), we then compared putative type III effectors among all available Xtu isolate genomes and found that they were highly conserved. However, there were striking differences in the presence and sequence of various transcription activator-like effectors between Xtu CO237 and published undulosa genomes, which correlate with isolate virulence. Here, we explore the potential implications of the differences in these virulence factors, and provide possible explanations for the increased virulence of recently emerged isolates.

Osteoinductive squamous cell carcinoma associated with a putative novel papillomavirus on the digit of a cat

ABSTRACT Case history and clinical findings An approximately 10-year-old, castrated male domestic short-haired cat developed swelling and ulceration of the second digit of the right front paw. Radiographs revealed a spherical soft tissue swelling with irregular distal margins that contained multiple lacy mineral opacities. The digit was amputated and submitted for histology. No recurrence has been observed 7 months after amputation. Pathological and molecular findings Histology revealed a moderately well-circumscribed proliferation of well-differentiated squamous cells arranged in trabeculae and nests. Numerous thin spicules of osseous metaplasia were visible throughout the neoplasm. Around 70% of the neoplastic cells contained papillomavirus-induced cell changes including large amphophilic cytoplasmic bodies and cells with shrunken nuclei surrounded by a clear halo. Intense p16CDKN2A protein immunostaining was visible within the neoplastic cells, suggesting papillomavirus-induced changes in cell regulation. A DNA sequence from a putative novel Taupapillomavirus type was amplified from the neoplasm. Diagnosis Osteoinductive squamous cell carcinoma associated with a putative novel papillomavirus type. Clinical relevance The findings in this case increase the number of papillomavirus types known to infect cats, and the squamous cell carcinoma had histological features that have not been previously reported. The neoplasm was not as invasive as is typical for a squamous cell carcinoma and excision appeared curative. This is the first report of an osteoinductive squamous cell carcinoma of the skin of cats and the neoplasm had a unique radiographic appearance.

Reproductive Parameters and Host Specificity of Eurytoma erythrinae (Hymenoptera: Eurytomidae), a Biological Control Agent of the Erythrina Gall Wasp, Quadrastichus erythrinae (Hymenoptera: Eulophidae).

Eurytoma erythrinae Gates & Delvare (Hymenoptera: Eurytomidae) is an important biological control agent of the erythrina gall wasp (EGW), Quadrastichus erythrinae Kim (Hymenoptera: Eulophidae), an invasive species likely originating in eastern Africa that is a threat to Erythrina trees in Hawaii and worldwide. Thousands of Erythrina trees in Hawaii have succumbed to EGW since 2005 and died within a few years of infestation. The endemic wiliwili tree, Erythrina sandwicensis, an important component of Hawaii's dry forests and one of few deciduous native trees, were severely impacted by this wasp. Early during the invasion by EGW it became evident that the endemic species may be driven to extinction, and exploration programs for natural enemies of the EGW started in December 2005. East Africa was selected as the starting point for natural enemy exploration owing to high native Erythina species richness. Several gall formers were found in Tanzania and a putative color variant type of Q. erythrinae was detected in association with three ectoparasitoids. During January 2006, the dominant parasitoid of this gall former was introduced to Hawaii and described as the new species, E. erythrinae. It was found in Ghana and South Africa attacking other gall wasp species on Erythrina. Eurytoma erythrinae was a voracious ectoparasitoid feeding as a predator on 1-5 adjacent EGW immatures to complete its development. Host specificity studies that included seven nontarget gall-forming species showed no evidence of attraction or parasitism by this parasitoid. Mean ± SEM longevity of host-deprived females (40.4 ± 2.2 days) was significantly higher than males (20.5 ± 1.1 days). Host feeding enhanced longevity of ovipositing females (51.3 ± 1.5 days). Female E. erythrinae is synovigenic, with high egg-maturation rate. Peak fecundity (105-239 offspring/female), host feeding biology, short life cycle (18.4 ± 0.1 days), and synchronization with the host were additional desirable attributes of this species. The parasitoid was approved for field release in Hawaii in November 2008. A total of 3998 wasps were distributed on six Hawaiian Islands, with establishment in less than a year. Impacts on high density infestations of EGW were sufficient to prevent tree deaths. Limited rates of parasitism on low-density galled leaves, flowers, and seedpods necessitated the consideration for releasing a second parasitoid, Aprostocetus nitens Prinsloo & Kelly (Hymenoptera: Eulophidae). We report on the reproductive characteristics and host specificity of E. erythinae that could be of importance for classical biocontrol programs in areas with an EGW problem.

Draft genome sequence of the emerging fish pathogen Flavobacterium tructae strain S12.

The draft genome of Flavobacterium tructae strain S12, isolated from hatchery-reared Chinook salmon (Oncorhynchus tshawytscha) fingerlings, consisted of 5,695,942 bp, a G + C content of 35.6%, 4,775 predicted open reading frames, a putative type IX secretion system, collagenase, and hemolysin. F. tructae strains can be used as models for emerging Flavobacterium pathogens.