DO Toxic Invasive Prey Become a Toxin Source for Native Consumers?

Toxic organisms can become food that potentially harms consumers. When these organisms become invasive species, the harm often turns to a serious threat that disrupts native ecosystems. On the other hand, there are consumers that can exploit toxic organisms for food and sequester intact toxins from them for the consumers' own chemical defense. Therefore, it can be expected that toxic invasive prey can become a toxin source for native consumers. Here, we focused on the relationship between toads, which are one of the major toxic invasive organisms and possess bufadienolides (BDs), and Rhabdophis snakes, which sequester BDs from toads. On Sado Island, Japan, R. tigrinus is native, but no toads had inhabited this island until Bufo japonicus formosus was introduced as a domestic invasive species in 1963 and 1964. At present, invasive toads are distributed only in the southwestern part of the island. We collected a total of 25 and 24 R. tigrinus from areas allopatric and sympatric with toads, respectively. Then, we investigated the possession of BDs and the BD profile of these snakes. We found that only R. tigrinus sympatric with toads possessed BDs, whereas all snakes allopatric with toads lacked BDs. Based on the characteristics of the BD profile, the toxin source was identified as B. j. formosus. Our findings show that a new case of impact caused by toxic invasive species, i.e., "toxin supply to native consumers from invasive prey", could occur.

A Nitrate-Transforming Bacterial Community Dominates in the Miscanthus Rhizosphere on Nitrogen-Deficient Volcanic Deposits of Miyake-jima.

The perennial gramineous grass Miscanthus condensatus functions as a major pioneer plant in colonizing acidic volcanic deposits on Miyake-jima, Japan, despite a lack of nitrogen nutrients. The nitrogen cycle in the rhizosphere is important for the vigorous growth of M. condensatus in this unfavorable environment. In the present study, we identified the nitrogen-cycling bacterial community in the M. condensatus rhizosphere on these volcanic deposits using a combination of metagenomics and culture-based analyses. Our results showed a large number of functional genes related to denitrification and dissimilatory nitrate reduction to ammonium (DNRA) in the rhizosphere, indicating that nitrate-transforming bacteria dominated the rhizosphere biome. Furthermore, nitrite reductase genes (i.e., nirK and nirS) related to the denitrification and those genes related to DNRA (i.e., nirB and nrfA) were mainly annotated to the classes Alpha-proteobacteria, Beta-proteobacteria, and Gamma-proteobacteria. A total of 304 nitrate-succinate-stimulated isolates were obtained from the M. condensatus rhizosphere and were classified into 34 operational taxonomic units according to amplified 16S rRNA gene restriction fragment pattern analysis. Additionally, two strains belonging to the genus Cupriavidus in the class Beta-proteobacteria showed a high in vitro denitrifying activity; however, metagenomic results indicated that the DNRA-related rhizobacteria appeared to take a major role in the nitrogen cycle of the M. condensatus rhizosphere in recent Miyake-jima volcanic deposits. This study elucidates the association between the Miscanthus rhizosphere and the nitrate-reducing bacterial community on newly placed volcanic deposits, which furthers our understanding of the transformation of nitrogen nutrition involved in the early development of vegetation.

Diversity and Distribution of Aspergillus fumigatus and Its Related Species in Izu and Ogasawara Islands, Japan.

The taxon Aspergillus section Fumigati comprises several causative agents of aspergillosis. Here, the distribution of Aspergillus sect. Fumigati in outdoor environments of Izu and Ogasawara Islands was investigated. Different strains were isolated from soil samples collected from 68 sites on 9 islands (Izu-oshima, Toshima, Shikinejima, Kozushima, Miyakejima, Hachijojima, Mukojima, Chichijima, and Hahajima), including different landscapes, and identified using morphological characteristics and calmodulin (CaM) sequences. Seven Aspergillus sect. Fumigati species were identified. The occurrence frequency of Aspergillus fumigatus was higher in forest sites on the islands, except for Ogasawara Islands, whereas that of species other than A. fumigatus was higher in bare land and grassland sites on all islands. The occurrence frequency of A. fumigatus was more than 50% on islands between Izu-oshima and Toshima, decreased on islands between Shikinejima and Hachijojima, and was zero on Ogasawara Islands. Considering other Aspergillus species, Aspergillus felis showed high occurrence frequency on islands between Izu-oshima and Shikinejima, Aspergillus pseudoviridinutans on islands between Kozushima and Hachijojima, and Aspergillus udagawae on Ogasawara Islands. At two study sites (grassland and forest sites), the soil was sampled throughout the year to evaluate whether the occurrence frequency of each fungal species was affected by sampling season. At the grassland site, A. pseudoviridinutans was isolated at more than 90% frequency, regardless of the sampling season. A. fumigatus occurrence frequency at the forest site ranged from 0% to 60% and greatly varied among sampling seasons. Thus, differences in island location and landscape affected the distribution of Aspergillus sect. Fumigati.

Photosynthetic Properties of Co-Occurring Pioneer Species on Volcanically Devastated Sites in Miyake-jima Island, Japan.

Pioneer species differing in their inherent ecological characteristics (e.g., N-fixing ability, photosynthetic pathway) can have a large impact on local ecosystems in the early stages of volcanic succession. However, it remains unclear as to how these pioneer species adapt to the extreme environment of volcanically devastated sites in terms of ecophysiological leaf traits. In this study, we compared the leaf traits (including morphological, physiological) of three co-occurring pioneer species, including a C4 non-N-fixing grass, a C3 N-fixing tree, and a C3 non-N-fixing herb from a newly created (18 years after eruption) volcanically devastated site in Miyake-jima, Japan. Our results showed that three pioneer species have different sets of leaf traits that are associated with their ecophysiological growth advantages, respectively. Miscanthus condensatus shows the highest light-saturated photosynthetic rate (Amax). The higher Amax were partially the result of higher water use efficiency (WUE) and photosynthetic N-use efficiency (PNUE). The PNUE in M. condensatus appears to be high, even for a C4 grass. Alnus sieboldiana rely on its N-fixing ability, has a higher leaf N content (Narea) that compensates for its photosynthetic machinery (Rubisco), and further ensures its photosynthetic capacity. Fallopia japonica var. hachidyoensis has a higher leaf mass per area (LMA), chlorophyll content (Chl), and maximum quantum yield of PSII (Fv/Fm), demonstrating its higher light capturing ability. These results make it possible to predict certain ecological processes that take place in the early stages of volcanic succession resulting from ecological characteristics and from some key leaf traits of pioneer species. It also provides a theoretical basis for species selection and species combination for volcanic ecological restoration.

Photosynthetic Properties of Miscanthus condensatus at Volcanically Devastated Sites on Miyake-jima Island.

How photosynthetic-related leaf traits of non-nitrogen (N)-fixing pioneer species respond to extreme habitat conditions of primary succession is still not well-elucidated, especially in volcanically N-deplete habitats. The effect of N-deplete soil on photosynthetic-related leaf traits can provide a basis for predicting how plants adjust their strategies to adapt to such habitats. To examine the responses of leaf traits to extreme conditions, we investigated Miscanthus condensatus (a non-N-fixing C4 pioneer grass) which grows on a volcanically devastated area on Miyake-jima Island, Japan, in which the volcanic ash has been deposited for 17-18 years since the 2000-year eruption. Leaf N content (Narea), light-saturated photosynthetic rate (Amax), and photosynthetic N use efficiency (PNUE) in three contrasting study sites: bare land (BL), shrub land gap (SLG), and shrub land under canopy (SLUC) were determined. Results indicated that compared to previous studies and internal comparison of Miyake Island, M. condensatus in BL was able to maintain a relatively high Amax, Narea and PNUE. The higher Amax was in part a result of the higher PNUE. This is a characteristic necessary for its successful growth in N-deplete soils. These results suggest that M. condensatus has photosynthetic-related advantages for adaptation to volcanically N-deplete habitats.

Large contribution of clonal reproduction to the distribution of deciduous liana species (Wisteria floribunda) in an old-growth cool temperate forest: evidence from genetic analysis.

Background and Aims: Extensive clonal (vegetative) reproduction in lianas is a common and important life history strategy for regeneration and colonization success. However, few studies have evaluated the contribution of clonal reproduction to stand-level distribution of lianas in their natural habitat using genetic tools. The objectives of the present study were to investigate (1) the contribution of clonal reproduction to the distribution of Wisteria floribunda, (2) the size of clonal patches and (3) how the distribution patterns of W. floribunda clones are affected by micro-topography. Methods: The contribution of clonal reproduction to the distribution of the deciduous liana species W. floribunda was evaluated using genetic analysis across a 6-ha plot of an old-growth temperate forest in Japan and preference in landform between clonal ramets and non-clonal ramets was assessed. Key Results: Of the 391 ramets sampled, clonal reproduction contributed to 71 and 62 % of the total abundance and basal area, respectively, or 57 and 31 % when the largest ramet within a genet was excluded. The large contribution of clonal reproduction to the density and basal area of W. floribunda was consistent with previous observational studies. The largest genet included a patch size of 0.47 ha and ranged over 180 m. Preferred landforms of clonal and non-clonal ramets were significantly different when evaluated by both abundance and basal area. Non-clonal ramets distributed more on lower part of the slope than other landforms in comparison with clonal ramets and trees, possibly reflecting the limitation of clonal growth by stolons. Conclusions: Using genetic analysis, the present study found evidence of a large contribution of clonal reproduction on the distribution of W. floribunda in its natural habitat. The results indicate that clonal reproduction plays an important role not only in the formation of populations but also in determining the distribution patterns of liana species.

Unique pioneer microbial communities exposed to volcanic sulfur dioxide.

Newly exposed volcanic substrates contain negligible amounts of organic materials. Heterotrophic organisms in newly formed ecosystems require bioavailable carbon and nitrogen that are provided from CO2 and N2 fixation by pioneer microbes. However, the knowledge of initial ecosystem developmental mechanisms, especially the association between microbial succession and environmental change, is still limited. This study reports the unique process of microbial succession in fresh basaltic ash, which was affected by long-term exposure to volcanic sulfur dioxide (SO2). Here we compared the microbial ecosystems among deposits affected by SO2 exposure at different levels. The results of metagenomic analysis suggested the importance of autotrophic iron-oxidizing bacteria, particularly those involved in CO2 and N2 fixation, in the heavily SO2 affected site. Changes in the chemical properties of the deposits after the decline of the SO2 impact led to an apparent decrease in the iron-oxidizer abundance and a possible shift in the microbial community structure. Furthermore, the community structure of the deposits that had experienced lower SO2 gas levels showed higher similarity with that of the control forest soil. Our results implied that the effect of SO2 exposure exerted a selective pressure on the pioneer community structure by changing the surrounding environment of the microbes.

Genetic differentiation and genetic diversity of Castanopsis (Fagaceae), the dominant tree species in Japanese broadleaved evergreen forests, revealed by analysis of EST-associated microsatellites.

The broadleaved evergreen forests of the East Asian warm temperate zone are characterised by their high biodiversity and endemism, and there is therefore a need to extend our understanding of its genetic diversity and phylogeographic patterns. Castanopsis (Fagaceae) is one of the dominant tree species in the broadleaved evergreen forests of Japan. In this study we investigate the genetic diversity, genetic structure and leaf epidermal morphology of 63 natural populations of C. sieboldii and C. cuspidata, using 32 Expressed Sequence Tag associated microsatellites. The overall genetic differentiation between populations was low (GST = 0.069 in C. sieboldii and GST = 0.057 in C. cuspidata). Neighbor-joining tree and Bayesian clustering analyses revealed that the populations of C. sieboldii and C. cuspidata were genetically clearly differentiated, a result which is consistent with the morphology of their epidermal cell layers. This suggests that C. sieboldii and C. cuspidata should be treated as independent species, although intermediate morphologies are often observed, especially at sites where the two species coexist. The higher level of genetic diversity observed in the Kyushu region (for both species) and the Ryukyu Islands (for C. sieboldii) is consistent with the available fossil pollen data for Castanopsis-type broadleaved evergreen trees during the Last Glacial Maximum and suggests the existence of refugia for Castanopsis forests in southern Japan. Within the C. sieboldii populations, Bayesian clustering analyses detected three clusters, in the western and eastern parts of the main islands and in the Ryukyu Islands. The west-east genetic differentiation observed for this species in the main islands, a pattern which is also found in several plant and animal species inhabiting Castanopsis forests in Japan, suggests that they have been isolated from each other in the western and eastern populations for an extended period of time, and may imply the existence of eastern refugia.

Characterization of early microbial communities on volcanic deposits along a vegetation gradient on the island of Miyake, Japan.

The 2000 eruption of Mount Oyama on the island of Miyake (Miyake-jima) created a unique opportunity to study the early ecosystem development on newly exposed terrestrial substrates. In this study, bacterial and fungal communities on 9- and 11-year-old volcanic deposits at poorly to fully vegetation-recovered sites in Miyake-jima, Japan, were characterized by conventional culture-based methods and pyrosequencing of 16S rRNA and 18S rRNA genes. Despite the differences in the vegetation cover, the upper volcanic deposit layer samples displayed low among-site variation for chemical properties (pH, total organic carbon, and total nitrogen) and microbial population densities (total direct count and culturable count). Statistical analyses of pyrosequencing data revealed that the microbial communities of volcanic deposit samples were phylogenetically diverse, in spite of very low-carbon environmental conditions, and their diversity was comparable to that in the lower soil layer (buried soil) samples. Comparing with the microbial communities in buried soil, the volcanic deposit communities were characterized by the presence of Betaproteobacteria and Gammaproteobacteria as the main bacterial class, Deinococcus- Thermus as the minor bacterial phyla, and Ascomycota as the major fungal phyla. Multivariate analysis revealed that several bacterial families and fungal classes correlated positively or negatively with plant species.

Clinical and molecular analysis of six Japanese patients with a renal form of pseudohypoaldosteronism type 1.

Pseudohypoaldosteronism type 1 (PHA1) is a rare condition characterized by neonatal salt loss with elevated plasma aldosterone and renin levels. Two types of PHA1 have been described: an autosomal recessive systemic form and an autosomal dominant renal form, in which the target organ defect is confined to the renal tubules. The dominant renal form of PHA1 is caused by heterozygous mutations in the NR3C2 gene, which encodes the mineralocorticoid receptor (MR). We determined clinical and biochemical parameters in two familial and four sporadic Japanese patient and analyzed the status of the NR3C2 gene. Failure to thrive was noted in five of the six patients. In one of the familial cases, the mother had an episode of failure to thrive when she was a toddler, but received no medical treatment. NaCl supplementation was discontinued in four of the six patients after they reached one year of age and they have grown normally thereafter. However, in one patient, 9 g/day of salt has been required to maintain serum Na concentration after 1 year of age. Analysis of NR3C2 identified three novel mutations [c. C1951T (p.R651X), c.304_305delGC (p.A102fsX103), c.del 603A (p.T201fsX34)] and one previously reported mutation [c.A2839G (p.947X)]. p.R651X was identified in one familial case and one unrelated sporadic patient. The patient who has been supplemented with large amount of salt was heterozygous for c.del 603A in exon 2. In conclusion, our study expands the spectrum of phenotypes, and characterized mutations of NR3C2 in the renal form of PHA1.

Complete genome sequence of Leptospirillum ferrooxidans strain C2-3, isolated from a fresh volcanic ash deposit on the island of Miyake, Japan.

A diazotrophic, acidophilic, iron-oxidizing bacterium, Leptospirillum ferrooxidans, known to be difficult to cultivate, was isolated from a fresh volcanic ash deposit on the island of Miyake, Japan. Here, we report the complete genome sequence of a cultured strain, C2-3.

Isolated growth hormone deficiency in two siblings because of paternal mosaicism for a mutation in the GH1 gene.

CONTEXT: Mutations in the GH1 gene have been identified in patients with isolated growth hormone deficiency (IGHD). Mutations causing aberrant splicing of exon 3 of GH1 that have been identified in IGHD are inherited in an autosomal dominant manner, whereas other mutations in GH1 that have been identified in IGHD are inherited in an autosomal recessive manner. OBJECTIVE: Two siblings born from nonconsanguineous healthy parents exhibited IGHD. To elucidate the cause, GH1 in all family members was analysed. RESULTS: Two novel mutations in GH1, a point mutation in intron 3 and a 16-bp deletion in exon 3, were identified by sequence analyses. The intronic mutation was present in both siblings and was predicted to cause aberrant splicing. The deletion was present in one of the siblings as well as the mother with normal stature and was predicted to cause rapid degradation of mRNA through nonsense-mediated mRNA decay. The point mutation was not identified in the parents' peripheral blood DNA; however, it was detected in the DNA extracted from the father's sperms. As a trace of the mutant allele was detected in the peripheral blood of the father using PCR-RFLP, the mutation is likely to have occurred de novo at an early developmental stage before differentiation of somatic cells and germline cells. CONCLUSIONS: This is the first report of mosaicism for a mutation in GH1 in a family with IGHD. It is clear that the intronic mutation plays a dominant role in the pathogenesis of IGHD in this family, as one of the siblings who had only the point mutation was affected. On the other hand, the other sibling was a compound heterozygote for the point mutation and the 16-bp deletion and it may be arguable whether IGHD in this patient should be regarded as autosomal dominant or recessive.

Analysis of early bacterial communities on volcanic deposits on the island of Miyake (Miyake-jima), Japan: a 6-year study at a fixed site.

Microbial colonization on new terrestrial substrates represents the initiation of new soil ecosystem formation. In this study, we analyzed early bacterial communities growing on volcanic ash deposits derived from the 2000 Mount Oyama eruption on the island of Miyake (Miyake-jima), Japan. A site was established in an unvegetated area near the summit and investigated over a 6-year period from 2003 to 2009. Collected samples were acidic (pH 3.0-3.6), did not utilize any organic substrates in ECO microplate assays (Biolog), and harbored around 106 cells (g dry weight)(-1) of autotrophic Fe(II) oxidizers by most-probable-number (MPN) counts. Acidithiobacillus ferrooxidans, Acidithiobacillus ferrivorans, and the Leptospirillum groups I, II and III were found to be abundant in the deposits by clone library analysis of bacterial 16S rRNA genes. The numerical dominance of Acidithiobacillus ferrooxidans was also supported by analysis of the gene coding for the large subunit of the form I ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO). Comparing the 16S rRNA gene clone libraries from samples differing in age, shifts in Fe(II)-oxidizing populations seemed to occur with deposit aging. The detection of known 16S rRNA gene sequences from Fe(III)-reducing acidophiles promoted us to propose the acidity-driven iron cycle for the early microbial ecosystem on the deposit.

Hyperinsulinemia may promote growth without GH in children after resection of suprasellar brain tumors.

It remains elusive what factors induce growth without growth hormone (GWGH) in children after neurosurgery of brain tumors. Growth velocity and endocrinological data were compared between the patients with and without GWGH. We experienced three patients with GWGH (median, 12 years; 2 germinoma and 1 craniopharyngioma; three females; group 1) and 11 patients without (12 years; 8 craniopharyngioma, 2 germinoma and 1 medulloblastoma; 7 males; group 2) after neurosurgery. All patients in group 2 received GH replacement therapy. Growth velocity and endocrinological data were compared. Median height velocity was normal in group 1 (5.5 cm/year), but low in group 2 (2.2 cm/year), which improved after GH replacement therapy (7.0 cm/year). Median serum insulin level was increased in group 1 (87.0 µU/ml, P < 0.05) compared with normal level in group 2 (10.0 µU/ml). Despite hyperinsulinemia, serum glucose level was normal in group 1. Three of 5 with hyperinsulinemia and 2 of 9 without were obese or overweight, but the difference was not significant. Current body mass index and serum levels of IGF-1, IGFBP-3, leptin, and prolactin were similar between groups. Serum estradiol was prepuberty level in group 1. Hyperinsulinemia may induce GWGH in children with brain tumors after neurosurgery.

Limnobacter litoralis sp. nov., a thiosulfate-oxidizing, heterotrophic bacterium isolated from a volcanic deposit, and emended description of the genus Limnobacter.

A Gram-negative, aerobic, heterotrophic bacterium, designated KP1-19(T), was isolated from a 22-year-old volcanic deposit at a site lacking vegetation on the island of Miyake, Japan. Strain KP1-19(T) was able to use thiosulfate (optimum concentration 10 mM) as an additional energy source. 16S rRNA gene sequence analysis indicated that strain KP1-19(T) was closely related to Limnobacter thiooxidans CS-K2(T) within the class Betaproteobacteria (97.7 % 16S rRNA gene sequence similarity). The cellular fatty acid profile was characteristic of the genus Limnobacter: the major fatty acids (>5 %) were C(16 : 0), C(16 : 1)ω7c and C(18 : 1)ω7c and minor amounts of C(10 : 0) 3-OH were also found. DNA-DNA relatedness between strain KP1-19(T) and L. thiooxidans LMG 19593(T) was 18 %. Therefore, strain KP1-19(T) represents a novel species, for which the name Limnobacter litoralis sp. nov. is proposed. The type strain is KP1-19(T) (=LMG 24869(T) =NBRC 105857(T) =CIP 109929(T)).

Molecular and enzymatic characterization of a subfamily I.4 lipase from an edible oil-degrader Bacillus sp. HH-01.

An edible-oil degrading bacterial strain HH-01 was isolated from oil plant gummy matter and was classified as a member of the genus Bacillus on the basis of the nucleotide sequence of the 16S rRNA gene. A putative lipase gene and its flanking regions were cloned from the strain based on its similarity to lipase genes from other Bacillus spp. The deduced product was composed of 214 amino acids and the putative mature protein, consisting of 182 amino acids, exhibited 82% amino acid sequence identity with the subfamily I.4 lipase LipA of Bacillus subtilis 168. The recombinant product was successfully overproduced as a soluble form in Escherichia coli and showed lipase activity. The gene was, therefore, designated as lipA of HH-01. HH-01 LipA was stable at pH 4-11 and up to 30°C, and its optimum pH and temperature were 8-9 and 30°C, respectively. The enzyme showed preferential hydrolysis of the 1(3)-position ester bond in trilinolein. The activity was, interestingly, enhanced by supplementing with 1 mM CoCl(2), in contrast to other Bacillus lipases. The lipA gene seemed to be constitutively transcribed during the exponential growth phase, regardless of the presence of edible oil.

Regular physical exercise improves physical motor functions and biochemical markers in middle-age and elderly women.

BACKGROUND: Lifestyle-related diseases among middle-age and elderly people have become serious problems. Underlying causes might be related to the changes in the lifestyle including the absence of regular physical exercise. METHODS: To clarify the significance of regular physical exercise to prevent lifestyle-related diseases, we studied motor functions and blood chemistry examinations in middle-age and elderly women (over 40 years old) who performed regular physical exercise for 2 years (exercise group) and those who initially did not (control group). RESULTS: In study 1, VO2max significantly increased in the exercise group compared with the control group in the under 60 years old groups. In the over 60 years old groups, VO2max, foot balance, and HDL cholesterol significantly increased. Plasma glucose at 120 minutes after the 75 g oral glucose tolerance test, fasting insulin, homeostasis model assessment (HOMA-R), and high sensitivity C-reactive protein (hsCRP) significantly decreased in the exercise group compared with the control group. In study 2, a 1-year exercise program significantly improved physical functions and biochemical markers in the control group. CONCLUSION: These results suggest that regular physical exercise might help to maintain sound motor functions and decrease insulin resistance and a risk for arteriosclerosis.

Nitrogenase activity (acetylene reduction) of an iron-oxidizing leptospirillum strain cultured as a pioneer microbe from a recent volcanic deposit on miyake-jima, Japan.

The genus Leptospirillum is known to dominate acid mine drainage and bioleaching systems. In this paper, we describe the isolation of iron-oxidizing bacteria closely related to Leptospirillum ferrooxidans from an acidic volcanic ash deposit on the island of Miyake (Miyake-jima), Japan. We further show the nitrogenase activity (acetylene reduction) for one (strain C2-1) of the isolates. The deposit harbored 1.2×10(8) total direct count (g dry weight)(-1) and 7.1×10(5) (most-probable-number, MPN) (g dry weight)(-1) of iron-oxidizer. A ferrous iron-limited, aerobic chemostat culture using Leptospirillum HH medium (pH 1.8) was performed to select and isolate the Leptospirillum group. Nine isolates were regarded as pure cultures based on uniform colony morphology on Fe(2+)-containing silica gel plates and absence of growth on 100-fold diluted nutrient broth plates. Six strains examined further shared 99.9-100% identity in 16S rRNA gene sequence with each other. Homology-based searches showed that all of the strains belonged to the Leptospirillum ferrooxidans clade. Strain C2-1 grown in ammonium sulfate-free Leptospirillum HH medium (pH 1.8) showed an initial rate of acetylene reduction of 58 µmol h(-1) (g cell carbon)(-1).

Characterization of herbaspirillum- and limnobacter-related strains isolated from young volcanic deposits in miyake-jima island, Japan.

The role of microbes in the early development of ecosystems on new volcanic materials seems to be crucial to primary plant succession but is not well characterized. Here we analyzed the bacterial community colonizing 22-year-old volcanic deposits of the Miyake-jima Island (Japan) using culture-based and 16S rRNA gene clone library methods. The majority of 91 bacterial isolates were placed phylogenetically in two clusters (A and B) of the Betaproteobacteria. Cluster A (82% of isolates) was related to the genus Limnobacter and Cluster B (9%) was affiliated with the Herbaspirillum clade. The clone library analysis supported the predominance of Cluster B rather than Cluster A. Strain KP1-50 of Cluster B was able to grow on a mineral medium under an atmosphere of H(2), O(2), and CO(2) (85:5:10), and characterized by its large-subunit gene of ribulose 1,5-bisphosphate carboxylase/oxygenase (rbcL) and nitrogenase reductase gene (nifH). In contrast, strains of Cluster A did not grow chemolithoautotrophically with H(2), O(2), and CO(2) but increased their cell biomass with the addition of thiosulfate to the succinate medium, suggesting the use of thiosulfate as an energy source. From phenotypic characterization, it was suggested that the Cluster A and B strains were novel species in the genus Limnobacter and Herbaspirillum, respectively.

A case with isolated growth hormone deficiency caused by compound heterozygous mutations in GH-1: a novel missense mutation in the initiation codon and a 7.6kb deletion.

OBJECTIVE: To characterize the cause of a sporadic isolated growth hormone deficiency in a single patient. METHODS: Genomic DNA was extracted from blood samples of the patient and his family. Exons and exon-intron junctions of the GH-1 gene were amplified by PCR and sequenced. To characterize possible GH-1 deletions we performed Southern blot analysis and PCR-restriction fragment length analyses. RESULTS: An adenine to guanine mutation at the first nucleotide of the initiation codon (Met [ATG](-26)Val [GTG]) of the GH-1 gene was identified in the patient and the mother. A 7.6kb GH-1 deletion was identified in the patient, the brother and the father. CONCLUSION: The patient was a compound heterozygote for an allele bearing a Met(-26)Val missense mutation inherited from his mother and an allele containing deletion of the entire GH-1 gene inherited from his father. The present missense mutation has not been described previously. Attention should be paid to the heterozygous gene deletion that is difficult to detect by PCR-based genetic analysis. The patient responded to GH replacement therapy fairly well, without developing anti-hGH antibody.