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Jiri Hulcr - One of the best experts on this subject based on the ideXlab platform.
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Video supplement V2 from A selective fungal transport organ (Mycangium) maintains coarse phylogenetic congruence between fungus-farming ambrosia beetles and their symbionts
2018Co-Authors: James Skelton, Craig C Bateman, Andrew J. Johnson, Michelle A. Jusino, Jiri HulcrAbstract:Extraction of Xylosandrus compactus Mycangium contents. Beetles were mounted live on ultrafine pins. Fungal masses were extracted from mycangia by applying gentle pressure to the scutellum. This technique allows a sanitary removal of the complete living fungal mass for quantification of viable spores by serial dilution and culture. Mycangia that did not contain a fungal mass were verified by complete eversion of the empty Mycangium
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the ambrosia symbiosis from evolutionary ecology to practical management
Annual Review of Entomology, 2017Co-Authors: Jiri Hulcr, Lukasz L StelinskiAbstract:The ambrosia beetle–fungus farming symbiosis is more heterogeneous than previously thought. There is not one but many ambrosia symbioses. Beetle-fungus specificity is clade dependent and ranges from strict to promiscuous. Each new origin has evolved a new Mycangium. The most common relationship with host trees is colonization of freshly dead tissues, but there are also parasites of living trees, vectors of pathogenic fungi, and beetles living in rotten trees with a wood-decay symbiont. Most of these strategies are driven by fungal metabolism whereas beetle ecology is evolutionarily more flexible. The ambrosia lifestyle facilitated a radiation of social strategies, from fungus thieves to eusocial species to communities assembled by attraction to fungal scent. Although over 95% of the symbiotic pairs are economically harmless, there are also three types of pest damage: tree pathogen inoculation, mass accumulation on susceptible hosts, and structural damage. Beetles able to colonize live tree tissues are mos...
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The ambrosia symbiosis is specific in some species and promiscuous in others: evidence from community pyrosequencing
The ISME Journal, 2015Co-Authors: Martin Kostovcik, Craig C Bateman, Miroslav Kolarik, Lukasz L Stelinski, Bjarte H Jordal, Jiri HulcrAbstract:Symbioses are increasingly seen as dynamic ecosystems with multiple associates and varying fidelity. Symbiont specificity remains elusive in one of the most ecologically successful and economically damaging eukaryotic symbioses: the ambrosia symbiosis of wood-boring beetles and fungi. We used multiplexed pyrosequencing of amplified internal transcribed spacer II (ITS2) ribosomal DNA (rDNA) libraries to document the communities of fungal associates and symbionts inside the mycangia (fungus transfer organ) of three ambrosia beetle species, Xyleborus affinis , Xyleborus ferrugineus and Xylosandrus crassiusculus . We processed 93 beetle samples from 5 locations across Florida, including reference communities. Fungal communities within mycangia included 14–20 fungus species, many more than reported by culture-based studies. We recovered previously known nutritional symbionts as members of the core community. We also detected several other fungal taxa that are equally frequent but whose function is unknown and many other transient species. The composition of fungal assemblages was significantly correlated with beetle species but not with locality. The type of Mycangium appears to determine specificity: two Xyleborus with mandibular mycangia had multiple dominant associates with even abundances; Xylosandrus crassiusculus (mesonotal Mycangium) communities were dominated by a single symbiont, Ambrosiella sp. Beetle mycangia also carried many fungi from the environment, including plant pathogens and endophytes. The ITS2 marker proved useful for ecological analyses, but the taxonomic resolution was limited to fungal genus or family, particularly in Ophiostomatales, which are under-represented in our amplicons as well as in public databases. This initial analysis of three beetle species suggests that each clade of ambrosia beetles and each Mycangium type may support a functionally and taxonomically distinct symbiosis.
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Transverse cross sections of adult female Ambrosiodmus lecontei heads showing position of mycangia within mouthparts.
2015Co-Authors: Li You, Craig C Bateman, David Rabern Simmons, Dylan P. G. Short, Matthew T. Kasson, Robert J. Rabaglia, Jiri HulcrAbstract:(A) Section showing entire head with paired mycangia behind the mandibles, with dashed line representing missing exoskeletal structure. (B) Compacted fungal hyphae constituting mycangial inoculum. (C) Loose hyphae from mycangial packet, with both small (arrows) and larger (arrowhead) hyphae, likely representing dimitic generative and skeletal hyphae, respectively. (D& E) Flavodon cf. flavus isolate 6860_sub_white_myce with dimitic generative (D) and skeletal (E) hyphae. Key: E, eye; F, frontal edge (accidentally damaged); m, Mycangium.
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Mycangia of Ambrosia Beetles Host Communities of Bacteria
Microbial Ecology, 2012Co-Authors: Jiri Hulcr, Lukasz L Stelinski, N. R. Rountree, S. E. Diamond, N. Fierer, R. R. DunnAbstract:The research field of animal and plant symbioses is advancing from studying interactions between two species to whole communities of associates. High-throughput sequencing of microbial communities supports multiplexed sampling for statistically robust tests of hypotheses about symbiotic associations. We focus on ambrosia beetles, the increasingly damaging insects primarily associated with fungal symbionts, which have also been reported to support bacteria. To analyze the diversity, composition, and specificity of the beetles’ prokaryotic associates, we combine global sampling, insect anatomy, 454 sequencing of bacterial rDNA, and multivariate statistics to analyze prokaryotic communities in ambrosia beetle mycangia, organs mostly known for transporting symbiotic fungi. We analyze six beetle species that represent three types of mycangia and include several globally distributed species, some with major economic importance ( Dendroctonus frontalis , Xyleborus affinis , Xyleborus bispinatus–ferrugineus , Xyleborus glabratus , Xylosandrus crassiusculus , and Xylosandrus germanus ). Ninety-six beetle mycangia yielded 1,546 bacterial phylotypes. Several phylotypes appear to form the core microbiome of the Mycangium. Three Mycoplasma (originally thought restricted to vertebrates), two Burkholderiales, and two Pseudomonadales are repeatedly present worldwide in multiple beetle species. However, no bacterial phylotypes were universally present, suggesting that ambrosia beetles are not obligately dependent on bacterial symbionts. The composition of bacterial communities is structured by the host beetle species more than by the locality of origin, which suggests that more bacteria are vertically transmitted than acquired from the environment. The invasive X . glabratus and the globally distributed X . crassiusculus have unique sets of bacteria, different from species native to North America. We conclude that the Mycangium hosts in multiple vertically transmitted bacteria such as Mycoplasma , most of which are likely facultative commensals or parasites.
Takema Fukatsu - One of the best experts on this subject based on the ideXlab platform.
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evolutionary relationship between platycerus stag beetles and their Mycangium associated yeast symbionts
Frontiers in Microbiology, 2020Co-Authors: Kohei Kubota, Masahiko Tanahashi, Kana Watanabe, Takema Fukatsu, Xuejiao Zhu, Kako KawakamiAbstract:Adult females of stag beetles (Coleoptera: Lucanidae) possess an ovipositor-associated Mycangium for conveying symbiotic microorganisms. In most lucanid species, their Mycangium contains yeast symbionts of the genus Scheffersomyces Kurtzman & M. Suzuki, 2010 that are known for their xylose-fermenting capability. The lucanid genus Platycerus Geoffroy, 1762 is a group of small blue stag beetles, in which ten Japanese species constitute a monophyletic clade. Here we examined the evolutionary relationships of these Japanese Platycerus species and their yeast symbionts, together with a Korean Platycerus species and other lucanid species as outgroup taxa. Based on the internal transcribed spacer (ITS) and the intergenic spacer (IGS) sequences, the yeast symbionts of all Platycerus species were closely related to each other and formed a monophyletic clade. There is no variation in ITS sequences of the yeast symbionts of the Japanese Platycerus species. Based on IGS sequences, the yeast symbionts formed clusters that largely reflected the geographic distribution of the host insects, being shared by sympatric Platycerus species except for P. delicatulus Lewis, 1883 and P. viridicuprus Kubota, Kubota & Otobe, 2008. The symbiont phylogeny was globally not congruent with the host COI-based phylogeny, although some local congruences were observed. Statistically significant correlations were detected between the genetic distances of COI sequences of the host insects and those of IGS sequences of the yeast symbionts in Japan. These results suggest that, at least to some extent, the host insects and the yeast symbionts may have experienced co-evolutionary associations. While the Japanese Platycerus species formed a monophyletic clade in the COI phylogeny, the yeast symbionts of Japanese P. viridicuprus were very closely related to those of Korean P. hongwonpyoi Imura & Choe, 1989, suggesting the possibility that a recent secondary contact of the two beetle species during a marine withdrawal, e.g., in the last glacial period, might have resulted in an inter-specific horizontal transmission of the yeast symbiont.
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Specificity and genetic diversity of xylose-fermenting Scheffersomyces yeasts associated with small blue stag beetles of the genus Platycerus in East Asia.
Mycologia, 2017Co-Authors: Masahiko Tanahashi, Jong-kuk Kim, Kana Watanabe, Takema Fukatsu, Kohei KubotaAbstract:Among insect-fungus relationships, xylose-fermenting Scheffersomyces yeasts are well known for their potential in utilizing wood hemicelluloses and their association with various wood-feeding insects. However, their specificity to host insects or strain-level diversity within host species has not been clearly elucidated. In the insect family Lucanidae, larvae usually feed on decaying wood, and adult females consistently possess a fungus-storage organ, called the Mycangium, near the abdominal tip. Here the authors investigated host-symbiont relationships between Scheffersomyces yeast symbionts and small blue stag beetles of the genus Platycerus (Coleoptera: Lucanidae) in East Asia by using intergenic spacer (IGS) region as a genetic marker. All yeast strains isolated from the female Mycangium of three Platycerus species, P. hongwonpyoi from Korea and P. acuticollis and P. delicatulus from Japan, were allied to Scheffersomyces segobiensis based on the sequences of the nrDNA 26S and internal transcribed spacer (ITS), in which no sequence difference was observed among those strains. However, IGS regions showed clear genetic differentiation within the yeast symbionts of P. hongwonpyoi, as well as between those of Korean and Japanese Platycerus species. In the IGS sequences, nucleotide substitutions were mainly distributed in the whole stretch of IGS1 and the anterior half of IGS2, whereas nucleotide gaps were localized at IGS1 and the middle of IGS2. Despite the conserved association between the Platycerus beetles and the specific strains of S. segobiensis in East Asia, geophylogenetic divergence patterns of the yeast symbionts were not concordant with those of the insect hosts.
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Fungal Farming in a Non-Social Beetle
2016Co-Authors: Wataru Toki, Masahiko Tanahashi, Katsumi Togashi, Takema FukatsuAbstract:Culturing of microbes for food production, called cultivation mutualism, has been well-documented from eusocial and subsocial insects such as ants, termites and ambrosia beetles, but poorly described from solitary, non-social insects. Here we report a fungal farming in a non-social lizard beetle Doubledaya bucculenta (Coleoptera: Erotylidae: Languriinae), which entails development of a special female structure for fungal storage/inoculation, so-called Mycangium, and also obligate dependence of the insect on the fungal associate. Adult females of D. bucculenta bore a hole on a recently-dead bamboo culm with their specialized mandibles, lay an egg into the internode cavity, and plug the hole with bamboo fibres. We found that the inner wall of the bamboo internode harboring a larva is always covered with a white fungal layer. A specific Saccharomycetes yeast, Wickerhamomyces anomalus ( = Pichia anomala), was consistently isolated from the inner wall of the bamboo internodes and also from the body surface of the larvae. Histological examination of the ovipositor of adult females revealed an exoskeletal pocket on the eighth abdominal segment. The putative Mycangium contained yeast cells, and W. anomalus was repeatedly detected from the symbiotic organ. When first instar larvae were placed on culture media inoculated with W. anomalus, they grew and developed normally to adulthood. By contrast, first instar larvae placed on either sterile culture media or autoclaved strips of bamboo inner wall exhibited arrested growth at the second instar, and addition of W. anomalus to the media resumed growth and development of the larvae. These results strongly suggest
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Mycangium associated with the ovipositor of adult females of Doubledaya bucculenta.
2013Co-Authors: Wataru Toki, Masahiko Tanahashi, Katsumi Togashi, Takema FukatsuAbstract:(A) A dorsal view of the tergum of the eighth abdominal segment. (B) A ventral view of the eighth abdominal segment. (C) A lateral view of the eighth abdominal segment that was embedded in paraffin and cut longitudinally. (D) A longitudinal tissue section of the eighth abdominal segment, stained with periodic acid-Schiff reagent and hematoxylin. Arrows in (B), (C) and (D) indicate the opening of Mycangium. Solid lines in (A), (C) and (D) correspond to the front edge of mycangial cavity. Abbreviations: M, Mycangium; O, ovipositor; Y, yeast cells; AT, anterior; DO, dorsal; PT, posterior; VE, ventral.
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Fungal farming in a non-social beetle.
Public Library of Science (PLoS), 2024Co-Authors: Wataru Toki, Masahiko Tanahashi, Katsumi Togashi, Takema FukatsuAbstract:Culturing of microbes for food production, called cultivation mutualism, has been well-documented from eusocial and subsocial insects such as ants, termites and ambrosia beetles, but poorly described from solitary, non-social insects. Here we report a fungal farming in a non-social lizard beetle Doubledaya bucculenta (Coleoptera: Erotylidae: Languriinae), which entails development of a special female structure for fungal storage/inoculation, so-called Mycangium, and also obligate dependence of the insect on the fungal associate. Adult females of D. bucculenta bore a hole on a recently-dead bamboo culm with their specialized mandibles, lay an egg into the internode cavity, and plug the hole with bamboo fibres. We found that the inner wall of the bamboo internode harboring a larva is always covered with a white fungal layer. A specific Saccharomycetes yeast, Wickerhamomyces anomalus ( = Pichia anomala), was consistently isolated from the inner wall of the bamboo internodes and also from the body surface of the larvae. Histological examination of the ovipositor of adult females revealed an exoskeletal pocket on the eighth abdominal segment. The putative Mycangium contained yeast cells, and W. anomalus was repeatedly detected from the symbiotic organ. When first instar larvae were placed on culture media inoculated with W. anomalus, they grew and developed normally to adulthood. By contrast, first instar larvae placed on either sterile culture media or autoclaved strips of bamboo inner wall exhibited arrested growth at the second instar, and addition of W. anomalus to the media resumed growth and development of the larvae. These results strongly suggest a mutualistic nature of the D. bucculenta-W. anomalus association with morphological specialization and physiological dependence. Based on these results, we compare the fungal farming of D. bucculenta with those of social and subsocial insects, and discuss ecological factors relevant to the evolution of fungal farming in a non-social insect
Thomas C. Harrington - One of the best experts on this subject based on the ideXlab platform.
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ambrosiella roeperi sp nov is the mycangial symbiont of the granulate ambrosia beetle xylosandrus crassiusculus
Mycologia, 2014Co-Authors: Thomas C. Harrington, Stephen W Fraedrich, Douglas Mcnew, Chase G Mayers, Sharon E ReedAbstract:Isolations from the granulate ambrosia beetle, Xylosandrus crassiusculus (Coleoptera: Curculionidae: Scolytinae: Xyleborini), collected in Georgia, South Carolina, Missouri and Ohio, yielded an undescribed species of Ambrosiella in thousands of colony-forming units (CFU) per individual female. Partial sequences of ITS and 28S rDNA regions distinguished this species from other Ambrosiella spp., which are asexual symbionts of ambrosia beetles and closely related to Ceratocystis spp. Ambrosiella roeperi sp. nov. produces sporodochia of branching conidiophores with disarticulating swollen cells, and the branches are terminated by thick-walled aleurioconidia, similar to the conidiophores and aleurioconidia of A. xylebori, which is the mycangial symbiont of a related ambrosia beetle, X. compactus. Microscopic examinations found homogeneous masses of arthrospore-like cells growing in the Mycangium of X. crassiusculus, without evidence of other microbial growth. Using fungal-specific primers, only the ITS rDNA region of A. roeperi was amplified and sequenced from DNA extractions of mycangial contents, suggesting that it is the primary or only mycangial symbiont of this beetle in USA.
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isolations from the redbay ambrosia beetle xyleborus glabratus confirm that the laurel wilt pathogen raffaelea lauricola originated in asia
Mycologia, 2011Co-Authors: Thomas C. Harrington, Hideaki Goto, Dilzara N Aghayeva, Hye Young Yun, Stephen W FraedrichAbstract:The laurel wilt pathogen Raffaelea laur- icola was hypothesized to have been introduced to the southeastern USA in the Mycangium of the redbay ambrosia beetle, Xyleborus glabratus, which is native to Asia. To test this hypothesis adult X. glabratus were trapped in Taiwan and on Kyushu Island, Japan, in 2009, and dead beetles were sent to USA for isolation of fungal symbionts. Individual X. glabratus were macerated in glass tissue grinders, and the slurry was serially diluted and plated onto malt agar medium amended with cycloheximide, a medium semiselec- tive for Ophiostoma species and their anamorphs, including members of Raffaelea. R. lauricola was isolated from 56 of 85 beetles in Taiwan and 10 of 16 beetles in Japan at up to an estimated 10 000 CFUs per beetle. The next most commonly isolated species was R. ellipticospora, which also has been recovered from X. glabratus trapped in the USA, as were two other fungi isolated from beetles in Taiwan, R. fusca and R. subfusca. Three unidentified Raffaelea spp. and three unidentified Ophiostoma spp. were isolated rarely from X. glabratus collected in Taiwan. Isola- tions from beetles similarly trapped in Georgia, USA, yielded R. lauricola and R. ellipticospora in numbers similar to those from beetles trapped in Taiwan and Japan. The results support the hypothesis that R. lauricola
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short title raffaelea lauricola wilt pathogen isolations from the redbay ambrosia beetle xyleborus glabratus confirm that the laurel wilt pathogen raffaelea lauricola originated in asia
2011Co-Authors: Thomas C. Harrington, Hye Young Yun, Dilzara N AghayevaAbstract:Isolations from the redbay ambrosia beetle, Xyleborus glabratus, confirm that the laurel wilt pathogen Raffaelea lauricola originated in Asia Thomas C. Harrington Hye Young Yun Department of Plant Pathology, 351 Bessey Hall, Iowa State University, Ames, Iowa 50011 Sheng-Shan Lu Division of Forest Protection, Taiwan Forestry Research Institute, 53 Nanhai Road, Taipei 10066, Taiwan Hideaki Goto Forestry and Forest Products Research Institute, Kyushu Research Center, Kurokami 4-11-16, 860-0862, Japan Dilzara N. Aghayeva Institute of Botany, Azerbaijan National Academy of Sciences, Badamdar 40, Baku AZ1073, Azerbaijan Stephen W. Fraedrich Southern Research Station, USDA Forest Service, Athens, Georgia 30605 Abstract: The laurel wilt pathogen Raffaelea lauricola was hypothesized to have been introduced to the southeastern USA in the Mycangium of the redbay ambrosia beetle, Xyleborus glabratus, which is native to Asia. To test this hypothesis adult X. glabratus were trapped in Taiwan and on Kyushu Island, Japan, in 2009, and dead beetles were sent to USA for isolation of fungal symbionts. Individual X. glabratus were macerated in glass tissue grinders, and the slurry was serially diluted and plated onto malt agar medium amended with cycloheximide, a medium In Press at Mycologia, published on April 6, 2011 as doi:10.3852/10-417
Stephen W Fraedrich - One of the best experts on this subject based on the ideXlab platform.
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ambrosiella roeperi sp nov is the mycangial symbiont of the granulate ambrosia beetle xylosandrus crassiusculus
Mycologia, 2014Co-Authors: Thomas C. Harrington, Stephen W Fraedrich, Douglas Mcnew, Chase G Mayers, Sharon E ReedAbstract:Isolations from the granulate ambrosia beetle, Xylosandrus crassiusculus (Coleoptera: Curculionidae: Scolytinae: Xyleborini), collected in Georgia, South Carolina, Missouri and Ohio, yielded an undescribed species of Ambrosiella in thousands of colony-forming units (CFU) per individual female. Partial sequences of ITS and 28S rDNA regions distinguished this species from other Ambrosiella spp., which are asexual symbionts of ambrosia beetles and closely related to Ceratocystis spp. Ambrosiella roeperi sp. nov. produces sporodochia of branching conidiophores with disarticulating swollen cells, and the branches are terminated by thick-walled aleurioconidia, similar to the conidiophores and aleurioconidia of A. xylebori, which is the mycangial symbiont of a related ambrosia beetle, X. compactus. Microscopic examinations found homogeneous masses of arthrospore-like cells growing in the Mycangium of X. crassiusculus, without evidence of other microbial growth. Using fungal-specific primers, only the ITS rDNA region of A. roeperi was amplified and sequenced from DNA extractions of mycangial contents, suggesting that it is the primary or only mycangial symbiont of this beetle in USA.
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isolations from the redbay ambrosia beetle xyleborus glabratus confirm that the laurel wilt pathogen raffaelea lauricola originated in asia
Mycologia, 2011Co-Authors: Thomas C. Harrington, Hideaki Goto, Dilzara N Aghayeva, Hye Young Yun, Stephen W FraedrichAbstract:The laurel wilt pathogen Raffaelea laur- icola was hypothesized to have been introduced to the southeastern USA in the Mycangium of the redbay ambrosia beetle, Xyleborus glabratus, which is native to Asia. To test this hypothesis adult X. glabratus were trapped in Taiwan and on Kyushu Island, Japan, in 2009, and dead beetles were sent to USA for isolation of fungal symbionts. Individual X. glabratus were macerated in glass tissue grinders, and the slurry was serially diluted and plated onto malt agar medium amended with cycloheximide, a medium semiselec- tive for Ophiostoma species and their anamorphs, including members of Raffaelea. R. lauricola was isolated from 56 of 85 beetles in Taiwan and 10 of 16 beetles in Japan at up to an estimated 10 000 CFUs per beetle. The next most commonly isolated species was R. ellipticospora, which also has been recovered from X. glabratus trapped in the USA, as were two other fungi isolated from beetles in Taiwan, R. fusca and R. subfusca. Three unidentified Raffaelea spp. and three unidentified Ophiostoma spp. were isolated rarely from X. glabratus collected in Taiwan. Isola- tions from beetles similarly trapped in Georgia, USA, yielded R. lauricola and R. ellipticospora in numbers similar to those from beetles trapped in Taiwan and Japan. The results support the hypothesis that R. lauricola
Masahiko Tanahashi - One of the best experts on this subject based on the ideXlab platform.
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evolutionary relationship between platycerus stag beetles and their Mycangium associated yeast symbionts
Frontiers in Microbiology, 2020Co-Authors: Kohei Kubota, Masahiko Tanahashi, Kana Watanabe, Takema Fukatsu, Xuejiao Zhu, Kako KawakamiAbstract:Adult females of stag beetles (Coleoptera: Lucanidae) possess an ovipositor-associated Mycangium for conveying symbiotic microorganisms. In most lucanid species, their Mycangium contains yeast symbionts of the genus Scheffersomyces Kurtzman & M. Suzuki, 2010 that are known for their xylose-fermenting capability. The lucanid genus Platycerus Geoffroy, 1762 is a group of small blue stag beetles, in which ten Japanese species constitute a monophyletic clade. Here we examined the evolutionary relationships of these Japanese Platycerus species and their yeast symbionts, together with a Korean Platycerus species and other lucanid species as outgroup taxa. Based on the internal transcribed spacer (ITS) and the intergenic spacer (IGS) sequences, the yeast symbionts of all Platycerus species were closely related to each other and formed a monophyletic clade. There is no variation in ITS sequences of the yeast symbionts of the Japanese Platycerus species. Based on IGS sequences, the yeast symbionts formed clusters that largely reflected the geographic distribution of the host insects, being shared by sympatric Platycerus species except for P. delicatulus Lewis, 1883 and P. viridicuprus Kubota, Kubota & Otobe, 2008. The symbiont phylogeny was globally not congruent with the host COI-based phylogeny, although some local congruences were observed. Statistically significant correlations were detected between the genetic distances of COI sequences of the host insects and those of IGS sequences of the yeast symbionts in Japan. These results suggest that, at least to some extent, the host insects and the yeast symbionts may have experienced co-evolutionary associations. While the Japanese Platycerus species formed a monophyletic clade in the COI phylogeny, the yeast symbionts of Japanese P. viridicuprus were very closely related to those of Korean P. hongwonpyoi Imura & Choe, 1989, suggesting the possibility that a recent secondary contact of the two beetle species during a marine withdrawal, e.g., in the last glacial period, might have resulted in an inter-specific horizontal transmission of the yeast symbiont.
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Specificity and genetic diversity of xylose-fermenting Scheffersomyces yeasts associated with small blue stag beetles of the genus Platycerus in East Asia.
Mycologia, 2017Co-Authors: Masahiko Tanahashi, Jong-kuk Kim, Kana Watanabe, Takema Fukatsu, Kohei KubotaAbstract:Among insect-fungus relationships, xylose-fermenting Scheffersomyces yeasts are well known for their potential in utilizing wood hemicelluloses and their association with various wood-feeding insects. However, their specificity to host insects or strain-level diversity within host species has not been clearly elucidated. In the insect family Lucanidae, larvae usually feed on decaying wood, and adult females consistently possess a fungus-storage organ, called the Mycangium, near the abdominal tip. Here the authors investigated host-symbiont relationships between Scheffersomyces yeast symbionts and small blue stag beetles of the genus Platycerus (Coleoptera: Lucanidae) in East Asia by using intergenic spacer (IGS) region as a genetic marker. All yeast strains isolated from the female Mycangium of three Platycerus species, P. hongwonpyoi from Korea and P. acuticollis and P. delicatulus from Japan, were allied to Scheffersomyces segobiensis based on the sequences of the nrDNA 26S and internal transcribed spacer (ITS), in which no sequence difference was observed among those strains. However, IGS regions showed clear genetic differentiation within the yeast symbionts of P. hongwonpyoi, as well as between those of Korean and Japanese Platycerus species. In the IGS sequences, nucleotide substitutions were mainly distributed in the whole stretch of IGS1 and the anterior half of IGS2, whereas nucleotide gaps were localized at IGS1 and the middle of IGS2. Despite the conserved association between the Platycerus beetles and the specific strains of S. segobiensis in East Asia, geophylogenetic divergence patterns of the yeast symbionts were not concordant with those of the insect hosts.
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Fungal Farming in a Non-Social Beetle
2016Co-Authors: Wataru Toki, Masahiko Tanahashi, Katsumi Togashi, Takema FukatsuAbstract:Culturing of microbes for food production, called cultivation mutualism, has been well-documented from eusocial and subsocial insects such as ants, termites and ambrosia beetles, but poorly described from solitary, non-social insects. Here we report a fungal farming in a non-social lizard beetle Doubledaya bucculenta (Coleoptera: Erotylidae: Languriinae), which entails development of a special female structure for fungal storage/inoculation, so-called Mycangium, and also obligate dependence of the insect on the fungal associate. Adult females of D. bucculenta bore a hole on a recently-dead bamboo culm with their specialized mandibles, lay an egg into the internode cavity, and plug the hole with bamboo fibres. We found that the inner wall of the bamboo internode harboring a larva is always covered with a white fungal layer. A specific Saccharomycetes yeast, Wickerhamomyces anomalus ( = Pichia anomala), was consistently isolated from the inner wall of the bamboo internodes and also from the body surface of the larvae. Histological examination of the ovipositor of adult females revealed an exoskeletal pocket on the eighth abdominal segment. The putative Mycangium contained yeast cells, and W. anomalus was repeatedly detected from the symbiotic organ. When first instar larvae were placed on culture media inoculated with W. anomalus, they grew and developed normally to adulthood. By contrast, first instar larvae placed on either sterile culture media or autoclaved strips of bamboo inner wall exhibited arrested growth at the second instar, and addition of W. anomalus to the media resumed growth and development of the larvae. These results strongly suggest
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Mycangium associated with the ovipositor of adult females of Doubledaya bucculenta.
2013Co-Authors: Wataru Toki, Masahiko Tanahashi, Katsumi Togashi, Takema FukatsuAbstract:(A) A dorsal view of the tergum of the eighth abdominal segment. (B) A ventral view of the eighth abdominal segment. (C) A lateral view of the eighth abdominal segment that was embedded in paraffin and cut longitudinally. (D) A longitudinal tissue section of the eighth abdominal segment, stained with periodic acid-Schiff reagent and hematoxylin. Arrows in (B), (C) and (D) indicate the opening of Mycangium. Solid lines in (A), (C) and (D) correspond to the front edge of mycangial cavity. Abbreviations: M, Mycangium; O, ovipositor; Y, yeast cells; AT, anterior; DO, dorsal; PT, posterior; VE, ventral.
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discovery of mycangia and the associated xylose fermenting yeasts in stag beetles coleoptera lucanidae
Naturwissenschaften, 2010Co-Authors: Masahiko Tanahashi, Kohei Kubota, Norihisa Matsushita, Katsumi TogashiAbstract:Most wood-feeding insects need an association with microbes to utilize wood as food, and some have special organs to store and convey the microbes. We report here the discovery of the microbe-storage organ (Mycangium) in stag beetles (Coleoptera: Lucanidae), which develop in decayed wood. The Mycangium, which was discovered in the abdomen, is present in all adult females of 22 lucanid species examined in this study, but absent in adult males. By contrast, adult insects of both sexes of selected Passalidae, Geotrupidae, and Scarabaeidae, which are related to Lucanidae, lacked mycangia similar to those of the lucanid species. Yeast-like microbes were isolated from the Mycangium of five lucanid species. DNA sequence analyses indicate that the microbes are closely related to the xylose-fermenting yeasts Pichia stipitis, Pichia segobiensis, or Pichia sp. known from the gut of a passalid species.
