The Experts below are selected from a list of 78 Experts worldwide ranked by ideXlab platform
Michael K Foos - One of the best experts on this subject based on the ideXlab platform.
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molecular identification of Pilobolus species from yellowstone national park
Mycologia, 2011Co-Authors: Michael K Foos, Kathy B SheehanAbstract:Pilobolus, a widely distributed coprophilous fungus, grows on herbivore dung. Species of Pilobolus traditionally are described with imprecise morphological characteristics potentially leading to misidentification. In this study we used PCR analysis of taxonomically informative sequences to provide more consistent species identification from isolates obtained in Yellowstone National Park. We collected Pilobolus park-wide from six taxa of herbivores over 9 y. Multiple transfers of single sporangium isolates provided pure cultures from which DNA was extracted. Sequence analysis of internal transcribed spacer (ITS) regions of DNA that code for rRNA genes were used to distinguish among similar species. We describe several species of Pilobolus associated with herbivores in various habitats, including two species not previously reported, P. heterosporus and P. sphaerosporus. Our results show that phylogenetic species identification of Pilobolus based on sequence analysis of pure culture isolates provides a more reliable means of identifying species than traditional methods.
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Pilobolus and lungworm disease affecting elk in yellowstone national park
Fungal Biology, 1997Co-Authors: Michael K FoosAbstract:Dictyocaulus viviparus and Pilobolus coexist in individual elk of the Yellowstone National Park's northern herd. It is suggested that Pilobolus transfers infective larvae to forage grasses, so spreading the lungworm disease.
Kathy B Sheehan - One of the best experts on this subject based on the ideXlab platform.
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molecular identification of Pilobolus species from yellowstone national park
Mycologia, 2011Co-Authors: Michael K Foos, Kathy B SheehanAbstract:Pilobolus, a widely distributed coprophilous fungus, grows on herbivore dung. Species of Pilobolus traditionally are described with imprecise morphological characteristics potentially leading to misidentification. In this study we used PCR analysis of taxonomically informative sequences to provide more consistent species identification from isolates obtained in Yellowstone National Park. We collected Pilobolus park-wide from six taxa of herbivores over 9 y. Multiple transfers of single sporangium isolates provided pure cultures from which DNA was extracted. Sequence analysis of internal transcribed spacer (ITS) regions of DNA that code for rRNA genes were used to distinguish among similar species. We describe several species of Pilobolus associated with herbivores in various habitats, including two species not previously reported, P. heterosporus and P. sphaerosporus. Our results show that phylogenetic species identification of Pilobolus based on sequence analysis of pure culture isolates provides a more reliable means of identifying species than traditional methods.
Hiroyoshi Kubo - One of the best experts on this subject based on the ideXlab platform.
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asexual reproductive organ specific expression of the glyceraldehyde 3 phosphate dehydrogenase 2 gene of Pilobolus crystallinus
Mycoscience, 2012Co-Authors: Hiroyoshi KuboAbstract:Pilobolus crystallinus has three putative glyceraldehyde-3-phosphate dehydrogenase (gapdh) genes (pcgapdh1, pcgapdh2 and pcgapdh3). The results of this study demonstrate that expression of pcgapdh2 was increased by irradiation and that this increased expression was correlated with the formation of asexual reproductive organs (trophocysts). Interestingly, expression of pcgapdh2 was restricted to trophocysts. The formation of trophocysts was likely promoted by light, and the expression of pcgapdh2 was increased as a result of trophocyst formation. This is the first report that shows the regulation of a gapdh gene in an organ-specific manner in fungi.
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Cloning and expression analysis of putative glyceraldehyde-3-phosphate dehydrogenase genes in Pilobolus crystallinus
Mycoscience, 2011Co-Authors: Hiroyoshi KuboAbstract:Putative glyceraldehyde-3-phosphate dehydrogenase ( gapdh ) genes were cloned from Pilobolus crystallinus with degenerated primers designed from conserved sequences in many GAPDHs. P. crystallinus had three gapdh homologue genes, named pcgapdh1 , pcgapdh2 , and pcgapdh3 . Deduced amino acid sequences for PCGAPDH1, PCGAPDH2, and PCGAPDH3 showed highest similarity with GPD3, GPD1, and GPD2, respectively, of Mucor circinelloides , indicating that these three gapdh genes had diverged before Pilobolus and Mucor were separated. The expression patterns of the gapdh genes, however, were quite different between P. crystallinus and M. circinelloides . All the three pcgapdh genes were expressed, and the expression of pcgapdh2 was suppressed by glucose and sodium acetate. These results indicate that the function of these orthologous genes was changed after Pilobolus and Mucor were separated.
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isolation of mada homologs in Pilobolus crystallinus
Mycoscience, 2009Co-Authors: Hiroyoshi KuboAbstract:Pilobolus crystallinus shows unique photoresponses at various growing stages. cDNAs for putative photoreceptors were cloned from this fungus. Three genes named pcmada1, pcmada2, and pcmada3 were identified from the PCR fragments, and amplified with degenerated primers for the LOV domain, which is conserved in many blue-light receptors. Deduced amino acid sequences for PCMADA1, PCMADA2, and PCMADA3 had one light-oxygen-voltage (LOV)-sensing and two PER-ARNT-SIM (PAS) domains. A zinc finger DNA-binding motif was conserved in the C-terminals of PCMADA1 and PCMADA3. However, PCMADA2 lacked the zinc finger motif. Expression of pcmada1 was suppressed by blue light whereas that of pcmada3 was promoted by blue-light irradiation.
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effects of microbeam light on growth and phototropism of Pilobolus crystallinus sporangiophores
Mycoscience, 1996Co-Authors: Hiroyoshi Kubo, Hitoshi MiharaAbstract:A small blue-light beam (50 μm in diam) was used to examine light-growth response and phototropism inPilobolus crystallinus sporangiophores. Continuous irradiation by microbeam of a region 100–150 μm from the apex promoted the growth of a dark-adapted sporangiophore for about 15 min after a lag period of 1–2 min. After the promotion, the growth rate fell below that before the irradiation. Irradiation of the apex of sporangiophore slightly promoted the growth but strongly inhibited the growth after the promotion. A smaller light beam (10 μm in diam) applied continuously at grazing incidence along one side of the sporangiophore caused bending toward the shaded side, implying that the irradiated side grew more rapidly than the shaded side and that the lens effect is involved in the phototropism of young sporangiophores ofP. crystallinus. The involvement of the lens effect was confirmed by the fact that a carotenoid-less mutant was 1.5–2 times more sensitive to unilateral blue light than the wild type, probably because of a smaller intracellular light attenuation during passage through the mutant cell.
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Lag period for phototropism in Pilobolus crystallinus sporangiophores
Mycoscience, 1996Co-Authors: Hiroyoshi Kubo, Hitoshi MiharaAbstract:The lag period for the second positive curvature was examined inPilobolus crystallinus sporangiophores. The lag period for curvature development was 20–30 min at lower fluence rates than 6.32 nmol/m2s but greatly extended at higher fluence rates. When a 20-min symmetrical irradiation with blue light was applied before a 20-min unilateral blue light irradiation, sporangiophores bent as much as those unilaterally and continuously irradiated for 40 min. However, when a 20-min unilateral irradiation was followed by a 20-min symmetrical irradiation, sporangiophores did not show any curvature. That is, the reaction during the first 20 min of the lag period is independent of light direction. This light-direction-independent lag period is considered to be the duration required for adaptation. The lag period for phototropism was also extended when fluence rate was reduced after the start of irradiation. These results suggested that an adaptation process is involved in phototropism ofPilobolus.
Hitoshi Mihara - One of the best experts on this subject based on the ideXlab platform.
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developmental stage dependent response of Pilobolus crystallinus sporangiophores to gravitative and centrifugal stimulation
Mycoscience, 1998Co-Authors: Tadashi Horie, Hitoshi Mihara, Atsushi Miyazaki, Christine Schimek, Joe Fukui, Toshisuke Tsuru, Maki Koseki, Tamotsu OotakiAbstract:Gravitropic response of sporangiophores ofPilobolus crystallinus was studied by successive microscopic observation of the sporangiophores horizontally placed in the dark (red light) and by analysis of sporangiophore response to centrifugal stimulation. Negative tropism against the gravitative and also centrifugal stimulation was found only in mature sporangiophores after development of sporangium and after the resumption of elongation beneath the fully-developed subsporangial vescle, but there was no response in younger sporangiophores, implying that the gravitative perception system of the sporangiophores is dependent on their developmental stages.
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effects of microbeam light on growth and phototropism of Pilobolus crystallinus sporangiophores
Mycoscience, 1996Co-Authors: Hiroyoshi Kubo, Hitoshi MiharaAbstract:A small blue-light beam (50 μm in diam) was used to examine light-growth response and phototropism inPilobolus crystallinus sporangiophores. Continuous irradiation by microbeam of a region 100–150 μm from the apex promoted the growth of a dark-adapted sporangiophore for about 15 min after a lag period of 1–2 min. After the promotion, the growth rate fell below that before the irradiation. Irradiation of the apex of sporangiophore slightly promoted the growth but strongly inhibited the growth after the promotion. A smaller light beam (10 μm in diam) applied continuously at grazing incidence along one side of the sporangiophore caused bending toward the shaded side, implying that the irradiated side grew more rapidly than the shaded side and that the lens effect is involved in the phototropism of young sporangiophores ofP. crystallinus. The involvement of the lens effect was confirmed by the fact that a carotenoid-less mutant was 1.5–2 times more sensitive to unilateral blue light than the wild type, probably because of a smaller intracellular light attenuation during passage through the mutant cell.
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Lag period for phototropism in Pilobolus crystallinus sporangiophores
Mycoscience, 1996Co-Authors: Hiroyoshi Kubo, Hitoshi MiharaAbstract:The lag period for the second positive curvature was examined inPilobolus crystallinus sporangiophores. The lag period for curvature development was 20–30 min at lower fluence rates than 6.32 nmol/m2s but greatly extended at higher fluence rates. When a 20-min symmetrical irradiation with blue light was applied before a 20-min unilateral blue light irradiation, sporangiophores bent as much as those unilaterally and continuously irradiated for 40 min. However, when a 20-min unilateral irradiation was followed by a 20-min symmetrical irradiation, sporangiophores did not show any curvature. That is, the reaction during the first 20 min of the lag period is independent of light direction. This light-direction-independent lag period is considered to be the duration required for adaptation. The lag period for phototropism was also extended when fluence rate was reduced after the start of irradiation. These results suggested that an adaptation process is involved in phototropism ofPilobolus.
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analysis of growth and rotational behavior of sporangiophores in Pilobolus crystallinus wiggers tode
Planta, 1993Co-Authors: Tamotsu Ootaki, N Ishikawa, K Konno, M Todoriki, Atsushi Miyazaki, Hitoshi MiharaAbstract:The growth and rotation of the sporangiophore of Pilobolus crystallinus, which are important factors in its phototropic behavior, were analyzed throughout its development. The sporangiophore initial emerged from the trophocyst and elongated at the extreme tip without rotating. The elongation rate of the sporangiophore apex then gradually decreased and the apex expanded radially to produce the sporangium, but no rotation occurred. A transient cessation of elongation after sporangium development was followed by resumption of both elongation and radial expansion in the region beneath the sporangium developing the subsporangial vesicle. Rotation was not obvious at this stage. Radial expansion of the subsporangial vesicle continued at a decreasing rate until full size was reached. Elongation then recommenced in the newly established growth zone in the upper region of the sporangiophore just beneath the subsporangial vesicle. During this period of growth, the sporangiophore rotated in a clockwise direction as viewed from above. All growth and rotation ceased about 1 h before ejection of the sporangium into the air. Based on these results, a modified classification of the developmental stages has been proposed.
Richard J Ellis - One of the best experts on this subject based on the ideXlab platform.
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photo induction of sporangia in Pilobolus crystallinus
Mycologia, 1996Co-Authors: Richard J EllisAbstract:The effects of light on sporangial produc- tion by Pilobolus crystallinus were studied using monochromatic light of three wavelengths and a wide variety of photon fluence rates and exposure durations. Plates of cultures grown for 9 d in dark- ness display ca. 1200 trophocysts, 40-90 very tall spo- rangiophores, and no sporangia. Exposure of these cultures to continuous blue light induced the for- mation of 50-90 short sporangiophores, followed by production of sporangia on both kinds of sporangi- ophores. Comparative wavelength effectiveness is partly a function of fluence rate and exposure time: At the two highest fluence rates (1.7 and 0.17 jimoles m2 sec), 420 nm and 450 nm are equally stimulatory while 450 nm irradiation is the most effective light studied at the two lowest intensities (0.017 and 0.001 (moles m2 sec). Irradiation with 480 nm light was never observed to be the most stimulatory and usu- ally was the least effective. These observations regard- ing wavelength effectiveness are similar to those re- ported for sporangiophore phototropism and in con- trast to the wavelength dependence of trophocyst ini- tiation in P kleinii. Reciprocity was not observed; exposure duration appears to be far more important than intensity. Total fluences required for sporangial formation are approximately four orders of magni- tude greater than those needed for phototropism.