Journal of invertebrate pathology最新文献

{"title":"Suppression of a transcriptional regulator, HexA, is essential for triggering the bacterial virulence of the entomopathogen, Xenorhabdus hominickii","authors":"Gahyeon Jin ,&nbsp;Ji-Seon Jeong ,&nbsp;Il-Hwan Kim ,&nbsp;Yonggyun Kim","doi":"10.1016/j.jip.2024.108219","DOIUrl":"10.1016/j.jip.2024.108219","url":null,"abstract":"<div><div>A nematode-symbiotic bacterium, <em>Xenorhabdus hominickii</em>, exhibits two distinct lifestyles. Upon infection of its host nematode into a target insect, <em>X. hominickii</em> is released into the insect hemocoel and becomes pathogenic. This study examines the critical transformation in bacterial life forms concerning the activity of a transcriptional regulator, HexA. When <em>X. hominickii</em> was cultured in tryptic soy broth, <em>HexA</em> was expressed during the stationary phase of bacterial growth. Conversely, <em>HexA</em> was expressed in the early growth stage within the insect host, <em>Spodoptera exigua</em>, when infected with <em>X. hominickii</em>. The transient expression of <em>HexA</em> was succeeded by the expression of another transcriptional regulator, <em>Lrp</em>, which led to the production of bacterial virulent factors. Expression of <em>HexA</em> was manipulated by replacing its promoter with an inducible promoter controlled by the inducer, <span>l</span>-arabinose. In the absence of the inducer, the mutant bacteria expressed <em>HexA</em> at a low level, resulting in a bacterial culture broth that was more effective at suppressing insect immune responses than the wild type. When the inducer was added, <em>HexA</em> was expressed at high levels, rendering the culture broth ineffective in immunosuppression. Interestingly, expression of <em>HexA</em> inhibited the expression of another transcriptional regulator, <em>Lrp</em>, which in turn induced the expression of a non-ribosomal peptide synthetase, <em>gxpS</em>, leading to the production of an immunosuppressive metabolite, GXP. Suppression of <em>HexA</em> expression in mutant bacteria augmented GXP levels in secondary metabolites. This indicates that infection of <em>X. hominickii</em> into the insect host represses <em>HexA</em> expression and upregulates <em>Lrp</em> expression, leading to GXP production. The GXP metabolites inhibit insect immunity, thus protecting the bacteria-nematode complex. Therefore, the suppression of <em>HexA</em> expression in the insect hemocoel is crucial for the bacteria’s transition from a symbiotic to a pathogenic life form.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108219"},"PeriodicalIF":3.6,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142406504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differences in phagosome acidification of Manila clam hemocytes in response to two Perkinsus species with contrasting proliferation dynamics in the host: P. olseni and P. mediterraneus","authors":"Vince Neil B. Fuertes,&nbsp;Yuho Watanabe,&nbsp;Naoki Itoh","doi":"10.1016/j.jip.2024.108216","DOIUrl":"10.1016/j.jip.2024.108216","url":null,"abstract":"<div><div>Understanding the factors determining the host ranges of <em>Perkinsus</em> spp., a significant group of pathogenic protozoans affecting shellfish, is essential for preventing their spread and designing effective control measures. Considering that differences in the ability to proliferate within the host may influence the determination of host range, we first injected six <em>Perkinsus</em> spp. into Manila clams <em>Ruditapes philippinarum</em> and monitored the variations of trophozoite numbers. Although all six species were detected in the challenged clams 28 days post infection, the infection intensities varied among species, and particularly two species showed contrasting infection trends: <em>P. mediterraneus</em> showed a decreasing trend of infection, declining to the lowest intensity, whereas that of <em>P. olseni</em> continuously increased, reaching the highest intensity. <em>In vitro</em> exposure to Manila clam hemocytes revealed that the survival of <em>P. mediterraneus</em> trophozoites was suppressed, in contrast to <em>P. olseni</em>, which maintained their viability. Despite similar phagocytic indices for both species, the rate of phagosome acidification was significantly higher for hemocytes phagocytizing <em>P. mediterraneus</em> than those targeting <em>P. olseni</em>. Notably, phagosome acidification was significantly suppressed in hemocytes phagocytizing live <em>P. olseni</em> trophozoites, suggesting that <em>P. olseni</em> may secrete a substance that modulates phagosome acidification, and thereby evades intracellular digestion by the host’s hemocytes. Conversely, <em>P. mediterraneus</em>, with a lower affinity for infecting Manila clams, did not exhibit such modulation. Based on these results, we consider that the ability to modulate phagosome acidification in host hemocytes might be at least one factor in determining the host range of <em>Perkinsus</em> species.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108216"},"PeriodicalIF":3.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142400509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Honey bee viruses in the yellow-legged hornet Vespa velutina (Lepelieter 1836): Prevalence, loads, and detection of replicative DWV and LSV forms","authors":"M. Shantal Rodríguez-Flores ,&nbsp;Ana R. Lopes ,&nbsp;Ana Diéguez-Antón ,&nbsp;M Carmen Seijo ,&nbsp;M. Alice Pinto","doi":"10.1016/j.jip.2024.108215","DOIUrl":"10.1016/j.jip.2024.108215","url":null,"abstract":"<div><div>Apiaries in Galicia, northwestern Spain, are currently facing the invasive alien species <em>Vespa velutina,</em> which is well established in the region. The pressure on honey bee colonies is high, resulting in both economic and ecological losses. Honey bee colonies also face the challenge of viruses, which are becoming increasingly diverse. In recent years, honey bee viruses have been spreading across taxonomic groups beyond Apoidea, infecting the Vespoidea superfamily. This cross-species spillover has raised concerns in the scientific community due to the potential risk of viruses spreading in ecosystems. Currently, there is a lack of knowledge on this topic, and further research is needed to address this issue. This study employed qPCR and sequencing to investigate the prevalence, loads, and presence of replicative forms of important honey bee viruses in <em>V. velutina</em> individuals collected from 11 apiaries in Galicia. All <em>V. velutina</em> individuals tested positive for DWV, BQCV, AKI complex (ABPV, KBV, and IAPV), or LSV but not for CBPV. DWV showed the highest prevalence (97.0 %) and loads, with both DWV-A (67.4 %) and DWV-B (32.6 %) being detected. The AKI complex (46.3 %) and LSV (43.3 %) were also common, whereas BQCV (11.9 %) was rarer. LSV is detected for the first time in <em>V. velutina</em>. LSV-2 was the dominant strain (82.1 %), and two less frequent (17.9 %) unknown strains were also detected. All 44 screened <em>V. velutina</em> samples carried the replicative form of DWV, and six of these also carried the replicative form of LSV, raising for the first time the possibility of co-infection in the hornet. The detection of honey bee viruses in <em>V. velutina</em>, and the ability of these viruses to spread to other species, may indicate a potential risk of spillover in the apiaries.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108215"},"PeriodicalIF":3.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142400510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Arbuscular mycorrhizal fungi influence belowground interactions between a specialist root-feeder and its natural enemy","authors":"Elizabeth Davidson-Lowe ,&nbsp;Nursyafiqi Zainuddin ,&nbsp;Olivia Trase ,&nbsp;Nathaniel McCarthy ,&nbsp;Jared Gregory Ali","doi":"10.1016/j.jip.2024.108200","DOIUrl":"10.1016/j.jip.2024.108200","url":null,"abstract":"<div><div>As primary producers, plants play a central role in mediating interactions across trophic levels. Although plants are the primary food source for herbivorous insects, they can protect themselves from herbivore damage. Many plants produce toxic compounds that directly reduce herbivore feeding, but plants also protect themselves indirectly by attracting natural enemies of the attacking herbivore through volatile signaling. These so-called tri-trophic interactions have historically been documented aboveground in aerial plant parts but are also known to occur belowground in root systems. In addition to herbivores, plants directly interact with other organisms, which can influence the outcomes of tri-trophic interactions. Arbuscular mycorrhizal fungi (AMF) are symbiotic soil microbes that colonize the roots of plants and facilitate nutrient uptake. These microbes can alter plant chemistry and subsequent resistance to herbivores. Few studies, however, have shown how AMF affect tri-trophic interactions above- or belowground. This study examines how AMF colonization affects the emission of root volatiles when plants are under attack by western corn rootworm, a problematic pest of corn, and subsequent attraction of entomopathogenic nematodes, a natural enemy of western corn rootworm. Mycorrhizal fungi increased rootworm survival but decreased larval weight. Differences were detected across root volatile profiles, but there was not a clear link between volatile signaling and nematode behavior. Nematodes were more attracted to non-mycorrhizal plants without rootworms and AMF alone in soil, suggesting that AMF may interfere with cues that are used in combination with volatiles which nematodes use to locate prey.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108200"},"PeriodicalIF":3.6,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of function modules in the co-expression protein–protein interaction network of Bombyx mori in response to Beauveria bassiana infection","authors":"Dingding Lü ,&nbsp;Zihe Wang ,&nbsp;Ya Wang ,&nbsp;Sheng Qin","doi":"10.1016/j.jip.2024.108214","DOIUrl":"10.1016/j.jip.2024.108214","url":null,"abstract":"<div><div><em>Beauveria bassiana</em> (<em>B. bassiana</em>) is a common fungal disease in sericulture. Previous research has primarily focused on investigating genes involved in innate immunity. However, the response of <em>Bombyx mori</em> (<em>B. mori</em>) to <em>B. bassiana</em> requires the coordination of other biological processes in addition to the immune system. We measured protein expression profile of <em>B. mori</em> after inoculating <em>B. bassiana</em> using iTRAQ technology in previous. Here we constructed a co-expression protein–protein interaction network of <em>B. mori</em> in response to <em>B. bassiana</em> infection. Subnetworks and modules were analyzed, and the functions of these modules were annotated. The results revealed the identification of numerous proteins associated with cellular immunity, including those involved in phagosomes, lysosomes, mTOR signaling, sugar metabolism, and the ubiquitin–proteasome pathway. Meanwhile, we observed that the pathways involved in protein synthesis were activated, including pyruvate and purine metabolism, RNA transport, ribosome, protein processing in endoplasmic reticulum, and protein export pathways, during <em>B. bassiana</em> infection. Based on this analysis, we selected six candidate genes (shock protein, ribosome, translocon, actin muscle-type A2, peptidoglycan recognition protein, and collagenase) that were found to be related to the response to <em>B. bassiana</em>. Further verification experiments demonstrated significant changes in their expression levels after inoculation with <em>B. bassiana</em>. These research findings provide new insights into the molecular mechanism of insect immune response to fungal infection.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108214"},"PeriodicalIF":3.6,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142375571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct effects of Xenorhabdus spp. cell-free supernatant on Meloidogyne incognita in tomato plants and its impact on entomopathogenic nematodes","authors":"M.M. González-Trujillo ,&nbsp;J. Artal ,&nbsp;I. Vicente-Díez ,&nbsp;R. Blanco-Pérez ,&nbsp;M. Talavera ,&nbsp;J. Dueñas-Hernani ,&nbsp;S. Álvarez-Ortega ,&nbsp;R. Campos-Herrera","doi":"10.1016/j.jip.2024.108213","DOIUrl":"10.1016/j.jip.2024.108213","url":null,"abstract":"<div><div>Entomopathogenic <em>Xenorhabdus</em> spp. bacteria, symbiont of the nematode <em>Steinernema</em> spp., shows potential for mitigating agricultural pests and diseases through bioactive compound production. The plant-parasitic nematode (PPN) <em>Meloidogyne incognita</em> affects the yield and quality of numerous crops, causing significant economic losses. We speculate that Cell-Free Supernatants (CFS) from <em>Xenorhabdus</em> spp. could reduce the impact of the root-knot nematode (RKN) <em>M. incognita</em> without negatively affecting entomopathogenic nematodes (EPNs), which are considered beneficial organisms. This study explored the activity of seven CFS against <em>M. incognita</em> (two populations, AL05 and Chipiona) and their possible effects on EPNs. The <em>in vitro</em> impact of CFS at 10 %, 40 %, and 90 % concentrations on nematode motility at four and 24 h were tested on the PPN <em>M. incognita</em> and two EPNs, <em>S. feltiae</em> and <em>H. bacteriophora.</em> Additionally, EPN viability and virulence were evaluated at two and five days. On the other hand, tomato plant-mesocosm experiments examined the activity of four CFS on <em>M. incognita</em> reproductive capacity and EPN virulence. <em>In vitro</em> exposure of <em>M. incognita</em> to 90 % concentration of CFS resulted in reductions of activity over 60 % after four hours of expossure in four out of seven CFS. In the <em>in vitro</em> evaluation of two species of EPNs, none of the CFS affected the activity across any tested doses after four hours of exposure nor after 24 h. Plant-mesocosm experiments showed that CFS application significantly reduced RKN galls, egg masses, and galling index. However, the virulence of both EPN species decreased 15 days after application, with a significant impact on <em>S. feltiae</em>. Overall, these findings suggest that CFS could be used as a bio-tool against <em>M. incognita</em> in tomato crops, mitigating its impact on plant growth. However, this study also highlights the necessity of investigating the effects of CFS on non-target organisms.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108213"},"PeriodicalIF":3.6,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142348367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acanthocephalan Profilicollis altmani infecting the mole crab Emerita brasiliensis in southeastern Brazil","authors":"Tatiana Medeiros Barbosa Cabrini ,&nbsp;Bruna N. Machado ,&nbsp;Raquel A.F. Neves ,&nbsp;Rogério T. Vianna ,&nbsp;Darlânia S. Silva ,&nbsp;Patricia Mirella da Silva","doi":"10.1016/j.jip.2024.108211","DOIUrl":"10.1016/j.jip.2024.108211","url":null,"abstract":"<div><div>Acanthocephalan parasites, specifically from the genus <em>Profilicollis</em>, are known to infect decapod crustaceans, including mole crabs like <em>Emerita brasiliensis</em>, which serve as intermediate hosts in their complex life cycles. This study reports the first occurrence of the acanthocephalan parasite <em>Profilicollis altmani</em> infecting the mole crab <em>Emerita brasiliensis</em> on a sandy beach in southeastern Brazil, thereby expanding the known geographic range of this parasite. Additionally, the study provides novel molecular data that enhance our understanding of the parasite’s taxonomy and distribution, including the first evidence of genetic variation within populations of the intermediate host <em>E. brasiliensis</em>. Phylogenetic analysis based on mitochondrial COX1 gene sequences confirmed the identification of the parasite and underlined small genetic differences among <em>P. altmani</em> populations. These findings suggest a weak genetic population structure of the parasite and underscore the need for further studies to understand gene flow among these populations. This work contributes to the knowledge of parasite-host interactions in sandy beach ecosystems. It highlights the importance of monitoring parasitic infections in species like <em>E. brasiliensis</em>, which play a crucial ecological role in these environments.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108211"},"PeriodicalIF":3.6,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142348365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing the nested PCR method for Decapod iridescent virus 1 (DIV1) targeting ATPase gene by reselecting the inner primers","authors":"Jing-Yi Xing ,&nbsp;An-Qi Li ,&nbsp;Xiao-Meng Guo ,&nbsp;Meng Wang ,&nbsp;Xin Guan ,&nbsp;Liang Qiu ,&nbsp;Qing-Li Zhang ,&nbsp;Jie Huang","doi":"10.1016/j.jip.2024.108212","DOIUrl":"10.1016/j.jip.2024.108212","url":null,"abstract":"<div><div>DIV1 has the characteristics of fast transmission and a broad host range. Its infection leads to a high mortality rate, posing a serious threat to the global crustacean aquaculture industry. In order to increase the accuracy of DIV1 detection and reduce the difficulty of result interpretation, this study modified the original nested PCR method targeting the DIV1 ATPase gene. The internal primers for the nested PCR were redesigned to produce a 338 bp amplification product in the second step PCR, effectively distinguishing the target band from primer dimers. The newly established nested PCR method exhibits strong specificity and high sensitivity, with a detection limit as low as 1.37 × 10¹ copies/reaction. The developed nested PCR assay provides new technical support for the accurate detection of DIV1 in global crustacean aquaculture.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108212"},"PeriodicalIF":3.6,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142348368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Construction and characterization of different hemolysin gene deletion strains in Vibrio parahaemolyticus (ΔhlyA, ΔhlyIII) and evaluation of their virulence","authors":"Jinyuan Che ,&nbsp;Shaojie Hu ,&nbsp;Qitong Fang ,&nbsp;Binghong Liu ,&nbsp;Zhuochen Liu ,&nbsp;Cunjie Hu ,&nbsp;Lei Wang ,&nbsp;Lekang Li ,&nbsp;Baolong Bao","doi":"10.1016/j.jip.2024.108210","DOIUrl":"10.1016/j.jip.2024.108210","url":null,"abstract":"<div><div><em>Vibrio parahaemolyticus</em>, a halophilic food-borne pathogen, possesses an arsenal of virulence factors. The pathogenicity of <em>V. parahaemolyticus</em> results from a combination of various virulence factors. <em>HlyA</em> and <em>hlyIII</em> genes are presumed to function in hemolysis, in addition to <em>tdh</em> and <em>trh</em> in <em>V. parahaemolyticus</em>. To confirm the hemolytic function of genes <em>hlyA</em> and <em>hlyIII</em>, Δ<em>hlyA</em> and Δ<em>hlyIII</em> strains of <em>V. parahaemolyticus</em> were separately constructed via homologous recombination. The cytotoxicity and pathogenicity of the Δ<em>hlyA</em> and Δ<em>hlyIII</em> strains were evaluated using a Tetrahymena-<em>Vibrio</em> co-culture model and an immersion challenge in <em>Litopenaeus vannamei</em>. Results indicated that the hemolytic activity of the Δ<em>hlyA</em> and Δ<em>hlyIII</em> strains decreased by approximately 31.4 % and 24.9 % respectively, compared to the WT strain. Both Δ<em>hlyA</em> and Δ<em>hlyIII</em> exhibited reduced cytotoxicity towards Tetrahymena<em>.</em> Then shrimp infection experiments showed LD₅₀ values for Δ<em>hlyA</em> and Δ<em>hlyIII</em> of 3.06 × 10⁸ CFU/mL and 1.23 × 10⁸ CFU/mL, respectively, both higher than the WT strain’s value of 2.57 × 10⁷ CFU/mL. Histopathological observations revealed that hepatopancreas from shrimps challenged with Δ<em>hlyA</em> and Δ<em>hlyIII</em> exhibited mild symptoms, whereas those challenged with the WT strain displayed severe AHPND. These findings indicate that the Δ<em>hlyA</em> and Δ<em>hlyIII</em> strains are significantly less virulent than the WT strain. In conclusion, both <em>hlyA</em> and <em>hlyIII</em> are vital virulence genes involved in hemolytic and cytotoxic of <em>V. parahaemolyticus</em>.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108210"},"PeriodicalIF":3.6,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142348366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular and ultrastructural characterization of a novel cryptic species of the Mesomycetozoea clade isolated from Manila clam, Ruditapes philippinarum, on the west coast of Korea","authors":"S.D.N.K. Bathige ,&nbsp;Seung-Hyeon Kim ,&nbsp;Yu Chen ,&nbsp;W.A.A.H. Kalhari ,&nbsp;Donghyun Lee ,&nbsp;Hyung-Bae Jeon ,&nbsp;Hyoun Joong Kim ,&nbsp;Kyung-Il Park","doi":"10.1016/j.jip.2024.108202","DOIUrl":"10.1016/j.jip.2024.108202","url":null,"abstract":"<div><div>In the present study, a cryptic species (IchX) was isolated from the hemolymph of the Manila clam, <em>Ruditapes philippinarum</em>, collected from the west coast region of South Korea. Following comprehensive molecular analysis, a partial sequence resembling the small subunit of the ribosomal RNA (SSU rRNA) gene was obtained, indicating that this species belonged to the class Mesomycetozoea, also known as Ichthyosporea. Detailed phylogenetic analyses based on SSU rRNA sequences placed IchX in a distinct clade within the order Dermocystida, class Mesomycetozoea, and showed that IchX is closely related to <em>Ichthyosporea</em> sp. Microscopic examination of <em>in vitro</em> cultured IchX cells revealed life-cycle stages of different sizes, from the endospore to sporangium through vegetative stages. An ameboid-like structure was observed in the early endospore stages as the characteristic feature of zoospores. Ultrastructural analyses using scanning electron microscopy revealed that all endospores and vegetative cell stages are spherical. Transmission electron microscopy revealed characteristic features, including a spindle pole body and membrane-decorated hyaline vesicles, consistent with those previously described in Mesomycetozoea. In addition, a prominent fibrillar structure was observed. Notably, the cell wall of mature IchX sporangia was digested with 2 M NaOH, while that of the endospores was resistant. This is the first report of a novel Mesomycetozoean from the Manila clams. Further taxonomic study of this organism and elucidation of its pathological characteristics are necessary.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108202"},"PeriodicalIF":3.6,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}