Researchers Database

IWAGUCHI Shin-ichi

FacultyFaculty Division of Natural Sciences Research Group of Biological Sciences
PositionAssociate Professor
Last Updated :2022/10/06

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Profile and Settings

  • Name (Japanese)

    Iwaguchi
  • Name (Kana)

    Shin-Ichi

Degree

  • Ph.D, Nagoya University
  • MS, Okayama University

Research Interests

  • ストレス耐性真菌Torulaspora delbrueckiiの凝集性メカニズム
  • 微生物由来揮発性有機化合物による深在性真菌感染症の診断法の開発
  • 野生酵母を利用した発酵食品開発
  • 病原真菌Candida属の分子細胞生物学

Research Areas

  • Life sciences, Ecology and environmental science
  • Life sciences, Food sciences
  • Life sciences, Applied microbiology
  • Life sciences, Bacteriology
  • Life sciences, Molecular biology

Research Experience

  • Oct. 2016, Mar. 2018, 奈良教育大学非常勤「遺伝学」「遺伝学実験」
  • Apr. 2007, 奈良女子大学理学部准教授
  • Apr. 2004, 奈良女子大学理学部助教授
  • 2002, 奈良教育大学非常勤「理科教育・遺伝学実習」
  • Apr. 2000, Jun. 2000, 文部省在外研究員・英国アバディーン大学分子細胞生物学科
  • Apr. 1997, Jun. 1997, 文部省在外研究員・米国ミネソタ州立大学遺伝細胞生物学科
  • Jul. 1994, 奈良女子大学理学部講師
  • Apr. 1992, Jun. 1994, 米国ミネソタ州立大学遺伝細胞生物学科・博士研究員(ポストドクトラルアソシエイト)

Education

  • Apr. 2000, Jun. 2000, University of Abredeen, Molecular Cellular Biology, 文部科学省在外研究員, United Kingdom
  • Apr. 1997, Jun. 1997, University of Minnesota, 遺伝細胞生物学部, 文部科学省在外研究員, United States
  • Apr. 1992, Jun. 1996, University of Minnesosta, Department of Genetics and Cell Biology, 博士研究員, United States
  • Apr. 1988, Mar. 1992, Nagoya University, Graduate School, Division of Medicine, 病理学系医真菌学, Japan
  • Apr. 1986, Mar. 1988, 岡山大学大学院, 理学研究科生物学専攻, Japan
  • Apr. 1982, Mar. 1986, Okayama University, Faculty of Science, Department of Biology, Japan

Teaching Experience

  • Genetics lab, Nara University of Education, 99 Oct. 2016
  • Genetics, Nara University of Education, 99 Oct. 2016

Association Memberships

  • 日本農芸化学会, Jan. 2016, 9999
  • 日本生物工学会, Jan. 2015, 9999
  • 日本細菌学会, Jan. 1996, 9999
  • 日本医真菌学会, Jan. 1996, 9999
  • 酵母研究会, Jan. 1994, 9999
  • American Society for Microbiology, Jan. 1992, 9999

Media Coverage

  • 「奈良の八重桜」, エルマガMOOK『関西の大学を楽しむ本』, 26 May 2016, Paper
  • 奈良女子大学発の日本酒、クリスタルチェリー, 週間プレイボーイ「特集、大学発ベンチャー食品が日本を救う」, 01 Dec. 2014, Paper
  • 第7862号「大学は美味しいフェア!」〜今年の注目は奈女大の「赤い純米酒」, 文教速報, 13 May 2013, Pr
  • 色は「奈良の八重桜」奈良女子大准教授、日本酒開発, 朝日新聞デジタル, 08 May 2013, Internet
  • 〈トピックス〉サクラの酵母で作った赤い日本酒, マイナビニュース・開発SE, May 2013, Internet
  • サクラから日本酒 奈良女子大など開発, 毎日新聞・毎日JP, 28 Apr. 2013, Paper
  • 桜色の日本酒 生産に成功, NHKテレビ(奈良放送局), 24 Apr. 2013, Media report
  • 薄紅色の純米酒 - 奈良女子大と“春鹿”が開発, 奈良新聞, 24 Apr. 2013, Paper

Ⅱ.研究活動実績

Published Papers

  • Refereed, Microbiology Resource Announcements, Draft Genome Sequence of NYR20, a Red Pigment-Secreting Mutant of Saccharomyces cerevisiae, Hiro Takahashi; Shin-ichi Iwaguchi; Hisashi Kondo; Taichiro Motomura; Masataka Murase; Anna Takahashi; Shuichi Fukuyoshi; Chiyoko Machida; Shin Kanamasa; Satoru Yamamoto; Takayuki Yoshizaki, Jan. 2021, 10, 1, Scientific journal
  • Refereed, Microbiology Resource Announcements, American Society for Microbiology, Draft Genome Sequence of Saccharomyces cerevisiae Strain P-684, Isolated from Prunus verecunda, Hiro Takahashi; Takayuki Yoshizaki; Hisashi Kondo; Taichiro Motomura; Masataka Murase; Anna Takahashi; Shuichi Fukuyoshi; Chiyoko Machida; Shin Kanamasa; Hiromi Shimizu; Shin-ichi Iwaguchi, ABSTRACT Saccharomyces cerevisiae strain P-684 is a yeast isolated from the flowers of Prunus verecunda ‘Antiqua,’ producing high quantities of malic and succinic acids in sake brewing. Here, we report the draft genome sequence of P-684, enlightening the mechanisms of biosynthesis of these organic acids by this strain., Oct. 2020, 9, 41, Scientific journal
  • Refereed, Venus, Development of 11 microsatellite markers and paternity analysis in the invasive apple snail Pomacea canaliculata., Yamamoto, S; Komasu, H; Kitaura, J; Aoyama, T; Iwaguchi, S; Nakamura, M; Kawane, M; Collins, T. M; Yusa, Y, 2018, 76, 79, 85, Scientific journal
  • Not Refereed, 生物工学, 奈良八重桜から分離した花酵母でつくった爽やかな旨味の清酒, 岩口伸一; 鈴木孝仁; 松澤一幸; 清水浩美; 大橋正孝; 都築正男; 藤野千代, 2009, 87, 7, 356, 357, Scientific journal
  • Refereed, Report of Nara Prefectural Institute of Industrial Technology, 奈良県工業技術センター, Isolation of useful yeasts from flowers called Naranoyaezakura (Prunus verecunda 'Antiqua') and development of Japanese sake brewing with the isolated yeast, 大橋正孝; 都築正男; 清水浩美; 松澤一幸; 藤野千代; 鈴木孝仁; 岩口伸一, 2009, 35, 35, 38, Research institution
  • Refereed, MEDICAL MYCOLOGY, INFORMA HEALTHCARE, The loss of parts of chromosome 7 followed by the insertion of URA cassette into RB2 on MRS in Candida albicans strain CAI-4, Shin-Ichi Iwaguchi; Mina Suzuki; Naomi Sakai; Koji Yokoyama; Takahito Suzuki, Clinical isolates of the medically important fungus Candida albicans show electrophoretic karyotype variations. Chromosome translocation is considered to be one of the possible mechanisms of karyotype variation and has been shown to occur very frequently at or near the unique repeated DNA sequences which comprise the Major Repeat Sequence (MRS) on the genome. The MRS consists of the repeated sequences RB2, RPS, and HOK. We previously showed the insertion at the RB2 region might initiate chromosome translocation in strain STN22u2 of C. albicans. To ask whether the insertion of a URA cassette into the RB2 but not into RPS and HOK causes chromosome translocation in C. albicans strains, we transformed three URA cassettes into strain CAI-4, which is commonly used as a host strain for gene knockout experiments. We found chromosome rearrangements followed the insertion of URA cassettes into RB2 in strain CAI-4. Three transformants had an extra chromosome showing the loss of the 7A and 7C region from one chromosome 7 homologue. The recombination occurred at or after the insertion of URA cassette into RB2. Insertion there seems to cause chromosome rearrangement and thus RB2 is considered one of the important elements for initiation of chromosome rearrangement., 2008, 46, 7, 655, 663, Scientific journal
  • Refereed, YEAST, JOHN WILEY & SONS LTD, Chromosome translocation induced by the insertion of the URA blaster into the major repeat sequence (MRS) in Candida albicans, S Iwaguchi; M Suzuki; N Sakai; Y Nakagawa; PT Magee; T Suzuki, Ellectrophoretic karyotype studies have shown that clinical isolates of Candida albicalls have extensive chromosome length polymorphisms. Chromosome translocation is one of the causes of karyotypic variation. Chromosome translocation events have been shown to occur very frequently at or near the major repeat sequence (MRS) on chromosomes. The MRS consists of the repeated sequences RB2, RPS and HOK, and the repeated sequences are considered to be the template for recombination. To investigate which element of the MRS is important for chromosome translocation, we constructed three cassettes, each containing a URA blaster and sequences homologous to one of the repeats, for insertion into the MRS region on the chromosomes. The ura3 strain STN22u2, which shows a stable, standard karyotype, was transformed with each construct. Insertion events with each cassette occurred at almost all chromosomes. Insertion into the RB2 repeat, but not into the RPS repeat, was accompanied by chromosome translocation in some transformants: chromosome translocations between chromosomes R and 7 and chromosomes I and 7 were found, as well as deletions of 7A and 7C from chromosome 7. We conclude that the insertion at the RB2 region may initiate chromosome translocation in C. albicans. Copyright (C) 2004 John Wiley Sons, Ltd., Jun. 2004, 21, 8, 619, 634, Scientific journal
  • Refereed, 臨床検査, 病原真菌データベース・Pathogenic Fuugi Database (PFDB)の公開, IWAGUCHI Shin-ichi, 2002, Vol.46, No.8:919-924
  • Refereed, YEAST, JOHN WILEY & SONS LTD, Extensive chromosome translocation in a clinical isolate showing the distinctive carbohydrate assimilation profile from a candidiasis patient, SI Iwaguchi; M Sato; BB Magee; PT Magee; K Makimura; T Suzuki, Variation of the electrophoretic karyotype is common among clinical strains of Candida albicans and chromosome translocation is considered one of the causes of karyotypic variation. Such chromosome translocations may be a mechanism to confer phenotypic diversity on the imperfect fungus C. albicans. A clinical strain, TCH23, from a vaginal candidiasis patient shows distinct carbohydrate assimilation profile, serotype B, no chlamydospore formation and an atypical karyotype (Asakura et al, 1991). To examine the taxonomic relationship among C. albicans, Candida dubliniensis and this strain, we sequenced the internal transcribed spacer 1 (ITS1) of nuclear ribosomal DNA. The ITS1 sequence of TCH23 was identical with that of C. albicans but not of C. dubliniensis. Thus, strain TCH23 was classified as a variant of C albicans with an atypical phenotype. The chromosomal DNAs of this strain were resolved into 13 bands on pulse-field gel electrophoresis (PFGE). Using DNA probes located at or near both ends of each chromosome of C. albicans, we investigated the chromosome organization of this strain. Referring to the SfiI map of C albicans 1006 (Chu et al, 1993), we found that seven chromosomal DNA bands in strain TCH23 were reciprocal chromosome translocations. One homologue from chromosomes 1, 2 and 6 and both homologues from chromosomes 4 and 7 participated in these events. One translocation product was composed of three SfiI fragments, one each from chromosomes 2, 4 and 7. We deduced the breakpoints of chromosome translocation from the physical map of this strain; between 1J and 1J1, between 2A and 2U, both ends of 4F2, between 6C and 6O and both ends of 7F. Copyright (C) 2001 John Wiley & Sons, Ltd., Aug. 2001, 18, 11, 1035, 1046, Scientific journal
  • Refereed, Nihon Ishinkin Gakkai zasshi = Japanese journal of medical mycology, 4, [Subtractive gene cloning using dynabeads oligo(dT)25 for elucidation of pseudohyphal formation in Candida tropicalis]., Imanishi Y; Kawai T; Iwaguchi S; Suzuki T; Kamihara T; Yokoyama K; Nishimura K, The dimorphic transition from yeast to pseudohyphae in Candida tropicalis occurs following the addition of ethanol to a synthetic medium containing glucose. We developed a method of subtractive gene cloning to isolate genes, of which the expression was apparently specific for pseudohyphal formation in this organism.
    Subtraction was performed between sense-strand cDNAs instead of mRNAs from cells of the ethanol culture and anti-sense cDNAs linking to Dynabeads oligo(dT)25 from those of the control culture. Dynabeads oligo(dT)25 are paramagnetic beads with 25 nucleotide-long chains of deoxythymidines covalently linked to their surface and were expected to be easily collected using a magnet. This method using Dynabeads oligo(dT)25 minimizes the degradation of mRNA and makes it easy to construct a cDNA library sufficient to analyze the genetic information on the yeast-to-hyphae transition.
    Using this strategy, we identified several genes including a homologue of CPP1 coding tyrosine phosphatase and a homologue of nmt1+ encoding protein, which was reported to regulate thiamine biosynthesis., 2001, 42, 4, 243, 251
  • Refereed, PLANT MORPHOLOGY, Pseudohyphal growth induced by exposure of yeast cells to subinhibitory levels of antifungal azoles in Candida tropicalis, Takahito Suzuki; Shin-Ichi Iwaguchi; Teijiro Kamihara, 2001, 13, 1, 2, 10, Scientific journal
  • Refereed, YEAST, JOHN WILEY & SONS LTD, High-frequency occurrence of chromosome translocation in a mutant strain of Candida albicans by a suppressor mutation of ploidy shift, S Iwaguchi; T Kanbe; T Tohne; PT Magee; T Suzuki, Significant occurrence of high-ploidy cells is commonly observed among many Candida albicans strains. We isolated two isogenic strains, STN21 and STN22, each from a half sector of a colony obtained after mild UV-irradiation of a Arg(-) derivative of CBS5736. The two strains were different from each other in ploidy states and chromosome organization. Although cells of STN22 were homogeneous in size and had a single nucleus, high-ploidy cells, with either a single large nucleus or several nuclei, were present together with apparently normal cells with a single nucleus in the cell population of STN21. Flow cytometry showed that STN22 was a stable diploid; however, STN21 seemed to be the mixture of different ploidy states, including diploid and tetraploid. The phenotype of STN21 containing high-ploidy cells is referred to here as the Sps(-) phenotype (suppressor of ploidy shift). STN22 showed a typical electrophoretic karyotype similar to strain 1006 in C. albicans. However, an extra chromosomal band appeared in some clones of STN21 at high frequency. By assignment of several DNA probes, this extra chromosome was shown to be a translocation of the 7F-7G portion of chromosome 7 with the 470 kb DNA segment containing H SfiI fragment from chromosome 4. Thus, this extra chromosome is a hybrid of 4H and 7F-7G. Since the isogenic Sps(+) strain STN22 exhibited no extra chromosome bands, a correlation is suggested between the Sps(-) phenotype and the occurrence of chromosome translocations. Copyright (C) 2000 John Wiley & Sons, Ltd., Mar. 2000, 16, 5, 411, 422, Scientific journal
  • Refereed, MICROBIOLOGY-UK, SOC GENERAL MICROBIOLOGY, Depolarized cell growth precedes filamentation during the process of ethanol-induced pseudohyphal formation in the yeast Candida tropicalis, T Suzuki; Y Imanishi; S Iwaguchi; T Kamihara, Ethanol has been reported to cause mycelial growth in Candida tropicalis Pk233, and mycelial growth has also been shown to be abolished by concomitant addition of myo-inositol. In this study, the process of ethanol-induced mycelial growth in this organism was examined in combination with cytological characterization of actin localization, Cultivation with ethanol gave biphasic growth curves. During the first growth phase (doubling time 2.4 h), there was an accumulation of swollen spherical yeast cells, instead of the oblong ones observed in the control culture, followed by the appearance of spherical daughter cells in chains. Randomly distributed actin patches were observed on these swollen yeast cells and the bud initiation sites of these cells appeared random. These observations suggested that ethanol caused depolarization of cell growth during the first phase. During the second growth phase (doubling time 7.4 h), pseudohyphal cells appeared, projecting from the swollen yeast cells. Activity of chitinase in the control culture rose during the exponential phase. In the ethanol culture the activity stayed at a low level throughout the growth phases. When pseudohyphal cells were transferred to fresh ethanol medium, yeast cells appeared from pseudohyphal filaments and changed their shape to spherical, and filamentation appeared to be inhibited during the first phase. From these observations, an initial effect of ethanol on C. tropicalis cells appeared to be depolarization of cell growth, and the resulting swollen cells grew as polar pseudohyphal cells. In the culture supplemented with both ethanol and inositol, or with both ethanol and sorbitol, the accumulation of swollen cells was not observed and single yeast cells with normal oblong shape were seen throughout the growth phases., Feb. 1998, 144, 403, 410, Scientific journal
  • Refereed, Japanese Journal of Medical Mycology, 2, A Search for Specific Genes Working on the Process of Mycelial Growth in Candida tropicalis, Suzuki T; Imanishi Y; Iwaguchi S; Kamihara T, 1998, 39, 61, 65, Scientific journal
  • Refereed, JOURNAL OF CLINICAL MICROBIOLOGY, AMER SOC MICROBIOLOGY, STRAIN RELATEDNESS OF CANDIDA-ALBICANS STRAINS ISOLATED FROM CHILDREN WITH LEUKEMIA AND THEIR BEDSIDE PARENTS, M DOI; M HOMMA; SI IWAGUCHI; K HORIBE; K TANAKA, Candida yeasts are occasionally recovered from patients with leukemia in spite of antifungal therapy used during chemotherapy. It is not yet known whether yeasts in these patients are of endogenous or exogenous origin. We examined the strain relatedness of Candida albicans isolated from three patients with leukemia (A, B, and C) and their bedside parents using pulsed-field gel electrophoresis (PFGE), restriction fragment length polymorphism (RFLP) by SmaI digestion, and the Southern hybridization patterns of the RFLPs by the C. albicans-specific probe RPS1. SmaI digestion and Southern hybridization by RPS1 showed identical or similar patterns among Candida isolates in patient A and his mother, although their karyotypes were different. Isolates from patient B and both parents showed identical electrophoretic karyotypes, SmaI digestion patterns, and hybridization patterns. Since electrophoretic karyotypes are more variable than RFLPs and their hybridization patterns, the identity of the last two suggests a close relatedness between strains. Our results also suggest that transmission of yeast strains may have occurred between patient A and his mother and between patient B and her parents. Isolates from patient C and her mother are thought to have originated from different strains, since different patterns were obtained in electrophoretic karyotypes, SmaI digestion patterns, and Southern hybridization patterns., Sep. 1994, 32, 9, 2253, 2259, Scientific journal
  • Refereed, JOURNAL OF BACTERIOLOGY, AMER SOC MICROBIOLOGY, DIVERSITY OF TANDEMLY REPETITIVE SEQUENCES DUE TO SHORT PERIODIC REPETITIONS IN THE CHROMOSOMES OF CANDIDA-ALBICANS, H CHIBANA; SI IWAGUCHI; M HOMMA; A CHINDAMPORN; Y NAKAGAWA; K TANAKA, In a previous study, a repeated sequence, RPS1, was cloned from the genomic DNA of Candida albicans. It was 2.1 kb in length and was tandemly repeated in a limited region of almost all of the chromosomes. In this study, we examined and characterized the diversity of the repeating structure of the RPS units. RPS units were of 2.1, 2.3, 2.5, and 2.9 kbp in length after digestion of the genomic DNA with SmaI and 2.1 and 2.3 kbp after digestion with PstI, with the differences being multiples of approximately 0.2 kbp. Moreover, one or two types of RPS unit were present specifically on each chromosome. We cloned 14 RPS units from the mixed DNA of chromosomes 1 and 2 and 59 RPS units from chromosome 6. These RPS units were classified into four types by their SfiI digestion profiles and chromosomal origins. Sequence comparisons revealed a tandem arrangement of internal, small repeating units of 172 bp. This unit of repetition was designated alt (C. albicans tandem repeating unit). The size of RPS units was variable, with sizes representing a series of increments of approximately 0.2 kbp that corresponded to the alt sequence. By contrast, the sequences other than the tandem repeats of alts were highly conserved, with homology of more than 98% among all cloned RPS units. These results suggested that RPS plays an important role in the organization and function of the chromosomes of C. albicans even though the actual function of RPS has not yet been clarified. Structural features of RPS that contains the repeated art sequence are discussed in relation to human alpha-satellite DNA with its tandem repeats of about 170 bp that are similar in size to alt, the repetition of which is responsible for the variations in the size of the higher-order repeats., Jul. 1994, 176, 13, 3851, 3858, Scientific journal
  • Refereed, JOURNAL OF GENERAL MICROBIOLOGY, SOC GENERAL MICROBIOLOGY, CLONAL SIZE-VARIATION OF RDNA CLUSTER REGION ON CHROMOSOME-XII OF SACCHAROMYCES-CEREVISIAE, A CHINDAMPORN; SI IWAGUCHI; Y NAKAGAWA; M HOMMA; K TANAKA, Using pulsed-field gel electrophoresis (PFGE), we have demonstrated clonal variation in the size of chromosome XII in a diploid strain of Saccharomyces cerevisiae X2180-2D. The sizes of the two chromosome XII homologues were very different: 2600 (L-type) and 1450 kb (S-type). The frequency with which we detected clonal size variation in the diploid, compared to that of the parental clones, was about 15-50% of the progeny clones and the range of the size variation of the homologues was 2580-2680 kb (L-type) and 1340-1500 kb (S-type), respectively. The homologue of the L-type appeared to be more frequently variable than that of the S-type. The size variation was shown to be derived from size changes in the rDNA cluster region, which is present in chromosome XII, by digesting the chromosome with XhoI, whose cutting site is not present in a rDNA repeat unit, and hybridizing to rDNA probes. The clonal size variation was also investigated in haploids from spores after meiosis. The L-type and S-type chromosomes segregated 2:2 in an ascus and the sizes of all the S-type chromosomes were shifted up, compared to the original diploid, though the L-type ones were stable. The S-type sizes of 1340, 1450 and 1780 kb in the original diploids changed into the ranges of 1475-1610 kb, 1520-1680 kb and 1820-2010 kb, respectively, in the segregants. Furthermore, we observed that the size of S-type chromosomes in haploid cells was gradually increasing in mitosis during successive subcultures. The rDNA units appeared to be amplified on the S-type chromosome., Jul. 1993, 139, 1409, 1415, Scientific journal
  • Refereed, JOURNAL OF GENERAL MICROBIOLOGY, SOC GENERAL MICROBIOLOGY, ISOLATION AND CHARACTERIZATION OF A REPEATED SEQUENCE (RPS1) OF CANDIDA-ALBICANS, S IWAGUCHI; M HOMMA; H CHIBANA; K TANAKA, A repeated sequence, named RPS1, approximately 2 kb in size, is found mainly in chromosome 6, the second most variable chromosome among the eight chromosomes of Candida albicans. Most of the RPS1 units of chromosome 6 seem to be located within a single region of about 100 kb in strain FC18. In both strains FC18 and NUM812, a part of RPS1 is apparently tandemly repeated. A unit of RPS1 has been cloned and sequenced. It consists of 2114 bp and has a GC content of 40 mol %. The repeat unit contains smaller repeats of about 80-170 bp which are called REP1, REP2, REP3, REP4 and REP5; REP2 is duplicated. The small repeats are classified into two groups by their homology. One comprises REP1, REP2 and REP5, and the other REP3 and REP4. They are termed the REP1 and REP3 families, respectively. The two families both contain a common 29 bp sequence, called COM29. The dispersed repetitive sequence RPS1 may be involved in chromosomal rearrangements and may in part explain chromosome polymorphism in C. albicans. The origin of RPS1 was not determined., Sep. 1992, 138, 1893, 1900, Scientific journal
  • Refereed, JOURNAL OF GENERAL MICROBIOLOGY, SOC GENERAL MICROBIOLOGY, CLONAL VARIATION OF CHROMOSOME SIZE DERIVED FROM THE RDNA CLUSTER REGION IN CANDIDA-ALBICANS, SI IWAGUCHI; M HOMMA; K TANAKA, Of the eight Candida albicans chromosomes, chromosome 2, assigned by the MGL1 probe, is more variable in size than the other chromosomes among strains. We found that the clonal variation of chromosome 2, which carries a rDNA gene, occurred at a frequency of up to 10% of the progeny clones. After total chromosomal digestion with XhoI, which has no recognition sites within the rDNA repeat unit, the fragments containing the rDNA cluster were detected by Southern hybridization. The difference in fragment sizes corresponded to the clonal size variation of chromosome 2. The intensity of hybridization with rDNA also correlated with the difference in size. In addition, there was no size change in the non-rDNA region as detected by NotI digestion of chromosome 2, and there was no observed change in the individual rDNA basic repeat unit size. From these lines of evidence, we confirmed that the clonal size variation of chromosome 2 which occurs at high frequency is derived from the size change of the rDNA cluster., Jun. 1992, 138, 1177, 1184, Scientific journal
  • Refereed, JOURNAL OF GENERAL MICROBIOLOGY, SOC GENERAL MICROBIOLOGY, ELECTROPHORETIC KARYOTYPES OF CLINICALLY ISOLATED YEASTS OF CANDIDA-ALBICANS AND C-GLABRATA, K ASAKURA; SI IWAGUCHI; M HOMMA; T SUKAI; K HIGASHIDE; K TANAKA, One-hundred-and-four isolates of yeast were collected from the vaginas of 97 outpatients. The isolates were identified by their characteristics in a carbohydrate assimilation test, a serological test and from their morphology. Candida albicans and Candida glabrata were the major isolates (75% and 20%, respectively). The karyotypes of the isolates were analysed by pulsed-field gel electrophoresis and almost all the karyotypes were distinguishable from one another when the band mobilities were carefully compared. Characteristics and karyotypes were not directly correlated, but seven C. albicans isolates (from six patients) had a common atypical karyotype and shared the same phenotypic. These isolates are inferred to be generated by a wide genomic reorganization and mutation and the phenotypic changes may be advantageous for survival. The karyotypes of the isolates recovered from individual patients after intervals of 1-6 months were all identical except for one or two highly variable bands which were identified with an rDNA probe. This suggests that the variable bands are too variable to be useful for distinguishing strains, but from the patterns of the identical bands (i.e. except for the variable bands) we concluded that strains from individual patients do not change, at least over short periods. This, coupled with the extensive inter-isolate variability in karyotype, will be useful for Candida source determination and epidemiological studies., Nov. 1991, 137, 2531, 2538, Scientific journal
  • Refereed, JOURNAL OF GENERAL MICROBIOLOGY, SOC GENERAL MICROBIOLOGY, VARIATION IN THE ELECTROPHORETIC KARYOTYPE ANALYZED BY THE ASSIGNMENT OF DNA PROBES IN CANDIDA-ALBICANS, S IWAGUCHI; M HOMMA; K TANAKA, By using pulsed-field gel electrophoresis, we have separated the entire chromosome bands and examined the electrophoretic karyotypes of 27 strains of Candida albicans. The electrophoretic karyotype varied widely among these strains. Their chromosomal DNAs were resolved into 7-12 bands ranging in size from 0.42 to 3.0 Mb. Most of the separated chromosomal bands were assigned by eight cloned C. albicans DNA probes. These results suggest that the haploid number of Ca. albicans chromosomes is eight. Each of the probes hybridized specifically to one or two bands of similar size in most strains. With the exception of the MGL1 probe, when two bands were detected by one probe, the size of one of them was very conserved whilst the other was of fairly variable size. The sizes of the chromosome bands assigned by the MGL1 probe were much more variable. As C. albicans is considered to be a diploid organism, it is inferred that the karyotype polymorphism between strains is mainly derived from wise size heterogeneity in one of the homologous chromosomes. Furthermore, we have confirmed species-specific and strain-specific variation in medically important Candida species (C. stellatoidea, C. tropicalis, C. parapsilosis, C. krusei, C. guilliermondii, C. kefyr and C. glabrata). Electrophoretic karyotype analysis is thus useful for species assignation. The TUB2 probe, encoding C. albicans beta-tubulin, hybridized to the chromosomal DNA of all the Candida species examined, but four C. albicans probes exhibited cross-species hybridization with C. stellatoidea only. The karyotype of C. stellatoidea seems to be within the range of the intraspecies variation observed in C. albicans., Dec. 1990, 136, 2433, 2442, Scientific journal
  • Medical Mycology Journal, (一社)日本医真菌学会, 白癬菌Trichophyton属3種の放出する微生物由来揮発性有機異合物(MVOCs), 岩口 伸一; 楊 彩佳; 戸根 一哉; 槇村 浩一, Aug. 2018, 59, Suppl.1, 82, 82
  • Medical Mycology Journal, (一社)日本医真菌学会, 微生物由来揮発性有機化合物(MVOCs)を利用した白癬の診断法の開発, 伊東 芙美花; 楊 彩佳; 戸根 一哉; 槇村 浩一; 岩口 伸一; 清水 浩美; 首藤 明子, Sep. 2017, 58, Suppl.1, 77, 77

MISC

  • 日本医真菌学会雑誌, 白癬菌Trichophyton属3種に特異的な微生物由来揮発性有機化合物(MVOCs), 岩口伸一; 槇村浩一, 2021, 62, Supplement 1
  • 日本細菌学雑誌(Web), Validity as diagnostic marker of MVOCs emitted from Trichophyton species, 岩口伸一, 2020, 75, 1
  • 日本ブドウ・ワイン学会誌, Application of Red-Pigment-Secreting Yeast NYR20 in Winemaking, 吉崎隆之; 江崎真奈; 小林由真; 山本覚; 岩口伸一, 2020, 31, 2
  • 日本農芸化学会大会講演要旨集(Web), 奈良八重桜から分離されたストレス耐性酵母で観察された凝集性, 上原澪來; 岩口伸一, 2019, 2019
  • Plant Morphology, タバコ培養細胞BY-2の細胞死誘導過程におけるDNA断片化へのタンパク質合成阻害の影響, 岡崎多希子; 澤井優; 坂田実咲; 岩口伸一; 酒井敦, 2018, 30, 1
  • Plant Morphology, タバコ培養細胞BY-2の3種類の細胞死誘導過程におけるDNA断片化プロセスの検討, 岡崎多希子; 田中碧; 東道詩織; 岩口伸一; 酒井敦, 2017, 29, 1
  • 日本生物工学会大会講演要旨集, 奈良八重桜酵母由来の赤色清酒酵母株の赤色色素の排出機構, 岩口伸一; 矢路夏未, 2015, 67th
  • Plant Morphology, 真菌カンジダの菌糸形成に関わるクオラム・センシング(定足数感知), 鈴木孝仁; 岩口伸一, 2008, 19and20, 1 (Web)
  • 日本植物学会大会研究発表記録, 石油分解酵母Candida tropicalisの菌糸形成にはMAPKキナーゼのリン酸化は関与しない, 岩口伸一; 飛弾光; 鈴木孝仁, 2008, 72nd
  • 日本医真菌学会雑誌, 不完全真菌Candida tropicalisの二形性におけるMAPキナーゼの役割, 岩口伸一; 鈴木孝仁, 2007, 48, Supplement 1
  • Plant Morphology, 不完全酵母の接合型遺伝子および性染色体と形態形成, 西村冴加; 竹内まり子; 岩口伸一; 鈴木孝仁, 2006, 18, 1 (Web)
  • Plant Morphology, 石油資化酵母のMAPキナーゼカスケードの菌糸形成過程での役割, 岩口伸一; 鈴木孝仁, 2006, 18, 1 (Web)
  • 日本細菌学雑誌, 不完全真菌Candida tropicalisの菌糸形成に関わる遺伝子制御(MAPキナーゼ関連遺伝子), 岩口伸一, 2005, 60, 1
  • 日本分子生物学会年会プログラム・講演要旨集, 石油資化酵母Candida tropicalisの菌糸形成過程でサブトラクション法により見出されたCtPP1(MAPキナーゼフォスファターゼ), 岩口伸一, 2004, 27th
  • Plant Morphology, 不完全酵母Candida albicansで発見された接合型類似遺伝子座とその性染色体とが関わる倍数性制御における役割, 鈴木孝仁; 竹内まり子; 中西典子; 岩口伸一, 2004, 16, 1 (Web)
  • 日本医真菌学会雑誌, 二形性酵母Candida tropicalisのMAPキナーゼホスファターゼ標的遺伝子のクローニング, 岩口伸一; 鈴木孝仁, 2002, 43, Supplement 2
  • Plant Morphology, 石油資化性酵母Candida tropicalisにおけるMAPキナーゼホスファターゼの菌糸形成調節の解析, 柴田鈴代; 岩口伸一; 上原悌次郎; 鈴木孝仁, 2001, 13, 1 (Web)
  • Plant Morphology, ビタミンB1には形態形成の調節因子としてのはたらきがある, 鈴木孝仁; 岩口伸一; 上原悌次郎, 2000, 12, 1 (Web)
  • 日本医真菌学会雑誌, サブトラクション法により偽菌糸形成過程で見出された不完全酵母Candida tropicalisのCtCPP1(MAPキナーゼフォスファターゼ), 岩口伸一; 鈴木孝仁, 2000, 41, Supplement 1
  • Not Refereed, Medical Mycology Journal, (一社)日本医真菌学会, 白癬菌Trichophyton属3種の放出する微生物由来揮発性有機異合物(MVOCs), 岩口 伸一; 楊 彩佳; 戸根 一哉; 槇村 浩一, Aug. 2018, 59, Suppl.1, 82, 82

Books etc

  • 深在性真菌症Q&A, 医薬ジャーナル社, IWAGUCHI Shin-ichi, 分担, Mar. 2006, 44-45, Not Refereed
  • 真菌症遺伝子診断 ?パルスフィールド電気泳動法による型別法?, メジカルセンス, IWAGUCHI Shin-ichi, 1997, 103-106頁, Not Refereed
  • Molecular Biology of pathogenic fungi : Laboratory manual[Chromosome isolation and digestion], Toles press, IWAGUCHI Shin-ichi, 1994, 91-94頁, Not Refereed
  • 医学微生物の新しい展開「酵母カンジダ・アルビカンス染色体多型性とそれに関与する反復配列」, 菜根出版, IWAGUCHI Shin-ichi, 1993, Not Refereed

Presentations

  • Poster presentation, 29 Oct. 2021, 30 Oct. 2021
  • Poster presentation, 15 Dec. 2020, 16 Dec. 2020
  • 岩口伸一; 槇村浩一, 日本医真菌学会雑誌, 白癬菌Trichophyton属3種に特異的な微生物由来揮発性有機化合物(MVOCs), 2021, 2021, 2021
  • 吉崎隆之; 江崎真奈; 小林由真; 山本覚; 岩口伸一, 日本ブドウ・ワイン学会誌, Application of Red-Pigment-Secreting Yeast NYR20 in Winemaking, 2020, 2020, 2020
  • 岩口伸一, 日本細菌学雑誌(Web), Validity as diagnostic marker of MVOCs emitted from Trichophyton species, 2020, 2020, 2020
  • 上原澪來; 岩口伸一, 日本農芸化学会大会講演要旨集(Web), 奈良八重桜から分離されたストレス耐性酵母で観察された凝集性, 2019, 2019, 2019
  • 岡崎多希子; 澤井優; 坂田実咲; 岩口伸一; 酒井敦, Plant Morphology, タバコ培養細胞BY-2の細胞死誘導過程におけるDNA断片化へのタンパク質合成阻害の影響, 2018, 2018, 2018
  • 伊東芙美花; 楊彩佳; 戸根一哉; 槙村浩一; 岩口伸一, 日本医真菌学会第61回総会、金沢, 微生物由来揮発性有機化合物(MVOCs)を利用した白癬の診断法の開発, 30 Sep. 2017, 30 Sep. 2017, 01 Oct. 2017
  • 江畑衿香; 岩口伸一, 日本医真菌学会第61回総会、金沢, 病原真菌Candida albicansの新規遺伝子ORF6813の喪失は核や液胞の形態異常、多倍数化を引き起こす, 30 Sep. 2017, 30 Sep. 2017, 01 Oct. 2017
  • 伊東芙美花; 首藤明子; 清水浩美; 楊彩佳; 戸根一哉; 槙村浩一; 岩口伸一, 日本農芸化学会2017年大会、札幌, 微生物由来揮発性有機化合物を指標とした真菌感染症の早期診断法の開発, 17 Mar. 2017, 17 Mar. 2017, 20 Mar. 2017
  • 岡崎多希子; 田中碧; 東道詩織; 岩口伸一; 酒井敦, Plant Morphology, タバコ培養細胞BY-2の3種類の細胞死誘導過程におけるDNA断片化プロセスの検討, 2017, 2017, 2017
  • Iwaguchi, S, 14th International Congress on Yeasts (ICY14), Mechanism of the pigment excretion in red refined sake strain derived from Nara-Yaezakura yeast, Saccharomyces cerevisiae, 11 Sep. 2016, 11 Sep. 2016, 14 Sep. 2016
  • 岩口伸一; 角井理衣, 日本農芸化学会2016年大会、札幌, 奈良八重桜の花から分離されたTorulaspora delbrueckii株のストレス耐性, 27 Mar. 2016, 27 Mar. 2016, 30 Mar. 2016
  • 岩口伸一, 第88回日本細菌学会総会、岐阜, 日和見感染真菌Candida albicansの新規遺伝子ORF6813の適切な転写レベルの維持は細胞増殖に必要である, 26 Mar. 2015, 26 Mar. 2015, 28 Mar. 2015
  • 岩口伸一; 矢路夏未, 日本生物工学会大会講演要旨集, 奈良八重桜酵母由来の赤色清酒酵母株の赤色色素の排出機構, 2015, 2015, 2015
  • 岩口伸一, 第74回酵母研究会, 不完全真菌 Candida albicans の染色体変異, 06 Mar. 2012
  • 橋本真帆; 岩口伸一; 横山耕治; 村山琮明; 鈴木孝仁, 病原真菌 Candida albicans の核相変換関連遺伝子, 21 Oct. 2011
  • Sachiyo Kaneko; Haruna Tanaka; Tomoko Kimura; Takae Takeuchi; Masato Kiuchi; Shin-ichi Iwaguchi; Koji Yokoyama; Takahito Suzuki, IUMS (International Union of Microbiological Societies), Physiological activity of microbial volatile organic compounds (MVOCs) as a growth regulator in the soil-derived fungal organisms, 2011
  • 岩口伸一, 第98回発酵学懇話会日本生物工学会関西支部, 奈良八重桜から分離した花酵母で造った爽やかな旨味の清酒, 26 Nov. 2010
  • Takae Takeuchi; Tomoko Kimura; Haruna Tanaka; Masato Kiuchi; Sachiyo Kaneko; Shin-ichi Iwaguchi; Takahito Suzuki, The 58th ASMS Conference on Mass Spectrometry and Allied Topics, Characterization of Fungi Using SPME-GC/MS of MVOCs Emitted from Aspergillus fumigatus, Aspergillus nidulans, Fusarium solani and Penicillium paneum, 2010
  • 岩口伸一; 飛弾光; 鈴木孝仁, 日本植物学会大会研究発表記録, 石油分解酵母Candida tropicalisの菌糸形成にはMAPKキナーゼのリン酸化は関与しない, 2008, 2008, 2008
  • 鈴木孝仁; 岩口伸一, Plant Morphology, 真菌カンジダの菌糸形成に関わるクオラム・センシング(定足数感知), 2008, 2008, 2008
  • 岩口伸一; 鈴木孝仁, 日本医真菌学会雑誌, 不完全真菌Candida tropicalisの二形性におけるMAPキナーゼの役割, 2007, 2007, 2007
  • 岩口伸一; 鈴木孝仁, Plant Morphology, 石油資化酵母のMAPキナーゼカスケードの菌糸形成過程での役割, 2006, 2006, 2006
  • 西村冴加; 竹内まり子; 岩口伸一; 鈴木孝仁, Plant Morphology, 不完全酵母の接合型遺伝子および性染色体と形態形成, 2006, 2006, 2006
  • 岩口伸一, 日本細菌学雑誌, 不完全真菌Candida tropicalisの菌糸形成に関わる遺伝子制御(MAPキナーゼ関連遺伝子), 2005, 2005, 2005
  • 鈴木孝仁; 竹内まり子; 中西典子; 岩口伸一, Plant Morphology, 不完全酵母Candida albicansで発見された接合型類似遺伝子座とその性染色体とが関わる倍数性制御における役割, 2004, 2004, 2004
  • 岩口伸一, 日本分子生物学会年会プログラム・講演要旨集, 石油資化酵母Candida tropicalisの菌糸形成過程でサブトラクション法により見出されたCtPP1(MAPキナーゼフォスファターゼ), 2004, 2004, 2004
  • 岩口伸一; 鈴木孝仁, 日本医真菌学会雑誌, 二形性酵母Candida tropicalisのMAPキナーゼホスファターゼ標的遺伝子のクローニング, 2002, 2002, 2002
  • 柴田鈴代; 岩口伸一; 上原悌次郎; 鈴木孝仁, Plant Morphology, 石油資化性酵母Candida tropicalisにおけるMAPキナーゼホスファターゼの菌糸形成調節の解析, 2001, 2001, 2001
  • 岩口伸一; 鈴木孝仁, 日本医真菌学会雑誌, サブトラクション法により偽菌糸形成過程で見出された不完全酵母Candida tropicalisのCtCPP1(MAPキナーゼフォスファターゼ), 2000, 2000, 2000
  • 鈴木孝仁; 岩口伸一; 上原悌次郎, Plant Morphology, ビタミンB1には形態形成の調節因子としてのはたらきがある, 2000, 2000, 2000

Awards

  • マイクロサテライトマーカーを用いたミョウガガイの矮雄間競争の解明, 日本生態学会, 2009
  • Sperm competition among dwarf males of Scalpellum stearnsii (Cirripedia: Lepadomorpha) as revealed by microsatellite markers., 国際甲殻類学会, 2009
  • 日本医真菌学会優秀論文賞, 2002

Industrial Property Rights

  • Patent right, ナラノヤエザクラ赤色色素生成酵母およびそれを用いる醸造酒の製造方法, IWAGUCHI Shin-ichi, Nara Women's University, 2013-101657, 23 Apr. 2013
  • Patent right, ナラノヤエザクラの花から分離した酵母及びその取得方法並びにこの酵母を用いた清酒の製造方法及びその他の飲食物の製造方法, IWAGUCHI Shin-ichi, 奈良県、国立大学法人奈良女子大学, 4601015, 2009, 201007, 29 Jul. 2010, 4601015, 29 Jul. 2010

Research Projects

  • 微生物が放出する揮発性有機化合物(MVOCs)を利用した微生物汚染、微生物感染の早期発見方法の開発, 0, 0, 0, 「揮発性有機化合物を指標とした真菌感染症の早期診断法の開発」日本学術振興会科学研究費補助金基盤研究(挑戦的萌芽研究)を実施中, Competitive research funding
  • 微生物を利用した発酵食品開発, 0, 0, 0, 酵母、カビを利用した発酵食品の研究開発、商品化協力, Competitive research funding
  • 野生酵母を利用した発酵食品開発, 0, 0, 0, Competitive research funding
  • 不完全真菌の二形性変換, 0, 0, 0, Competitive research funding
  • 不完全真菌の倍数性変換機構, 0, 0, 0, Competitive research funding
  • 不完全真菌における染色体再配列のメカニズム, 0, 0, 0, Competitive research funding
  • Dimorphism in fungi, 0, 0, 0, Competitive research funding
  • Ploidy shift in Fungi, 0, 0, 0, Competitive research funding
  • Chromosome rearrangement in Fungi, 0, 0, 0, Competitive research funding
  • Grant-in-Aid for Scientific Research (C), 2010, 2012, 22570020, Adaptive significance of dwarf males in deep-sea barnacles, YUSA Yoichi; IWAGUCHI Shinichi, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Nara Women's University, 4550000, 3500000, 1050000, The adaptive significance of dwarf males is addressed in deep-sea barnacles. First, microsatellite markers were developed in Scalpellum stearnsii, and the reproductive success of their dwarf males was studied. Small males attained higher reproductive success than larger ones. Second, life history traits were studied and some pieces of information were obtained in this species and in a related species, S. scalpellum, in situ and/or in the aquarium. Third, using mathematical models and theoretical synthesis by reviewing relevant studies, it was suggested that dwarf males evolved under low-density conditions., url
  • Grant-in-Aid for Challenging Exploratory Research, 2010, 2012, 22659086, Development of early diagnostic method for Deep mycoses by monitoring volatile organic compounds, IWAGUCHI Shin-ichi; TAKEUCHI Takae; SUZUKI Takahito; YOKOYAMA Koji, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, Nara Women's University, 3060000, 2700000, 360000, We evaluated the availability of VOCs (volatile organic compounds) as the biomarker during the pulmonary invasive aspergillosis in murine infection model. We established the murine infection model and developed the apparatus for trapping of VOCs in murine breath. The detection of VOCs was performed by the SPME (solid phase microextraction)/ GC-MS (gas chromatography- mass spectrometry) method. Although we found several VOCs (2-ethyl-1-decanol、 2,3,6-trimethyl-octane、Isothiocyanatocyclohexane、1, 4-Methanoazulene (Longifolene)) in mouse chamber, there is no significant difference in TIC chromatograph between healthy and infected mouse. Thus we must reconsider the method for fungal infection., url
  • Grant-in-Aid for Scientific Research (B), 2008, 2010, 20300288, Analytical studies on microbial volatile organic compounds (MVOCs) and their physiological role in the microbial communities participating in the degradation of cultural properties., SUZUKI Takahito; TAKEUCHI Takae; IWAGUCHI Shinーichi, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Nara Women's University, 19370000, 14900000, 4470000, (1) Some microorganisms and their communities play a role of deterioration on cultural heritage materials. Detection of their emergence at an earlier stage allows for reducing risks of the deterioration. Emission of MVOCs seems to be an effective candidate for an indicator of the occurrence of their growth. The MVOCs were collected by solid phase micro extraction (SPME) and analyzed by gas-chromatography/mass spectrometry (GC/MS) from the representative microorganisms relating the deterioration, including five fungal genera ( Aspergillus, Penicillium, Acremonium, Fusarium and Aureobasidium) and bacterial Streptomyces. We constructed the Finger Print Database (FPD) of MVOCs determined by GC/MS. We succeeded in developing an innovative apparatus detecting MVOCs based on the principle of ion mobility spectrometry. The FPD of MVOCs was also constructed by IMS. (2) A species of springtail (Collembola) was isolated from soil and its behavior on the flavor of several fungal species, described above, was analyzed using a video-camera. The springtail was found to feed on Penicillium. They did not show a significant feeding attraction or avoidance behavior against those fungi, either. However, obvious attractive one was found to the fungus Cladosporium. (3) The co-culturing system was applied to allow free gas or volatile exchange between the colonies of two fungal species. The effects of Fusarium solani volatiles were found on growth and development of the other fungi Aspergillus fumigatus and Penicillium paneum. Colonies of F. solani were incubated in the same growth chamber as colonies of either A. fumigatus or P. paneum. Analzing MVOCs by GC/MS, 2-pentadecanone, emitted from F. solani, was suggested as an accelerator of conidiophore development in both A. fumigatus and P. paneum. However, benzaldehyde from F. solani, may be an allelochemical inhibitor of growth against both A. fumigatus and P. paneum. (4) As a cooperative research with Prof. Nishiyama at Nara University, we obtained fungal isolates from the Takaida burial cave located at Kashiwara-shi, Osaka, Japan. Using these isolates, the occurrence of growth was investigated by simulation analysis on the process of their growth on the surface of tuff stones in the controlled environment. Fungal growth and the formation of conidia were found on these experiments., url
  • Grant-in-Aid for Scientific Research (C), 2007, 2009, 19570019, Factors affecting sex-ratio variation and sex-determining mechanisms in the apple snail Pomacea canaliculata, YUSA Yoichi; IWAGUCHI Shin-ichi, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Nara Women's University, 3770000, 2900000, 870000, The freshwater snail Pomacea canaliculata shows a large variation in offspring sex ratio. We investigated whether this variation is caused by a small number of sex-determining genes, with two series of experiments. First, we reared F2 offspring from several crosses involving full-sib sisters with the same male, and determined sex ratios of F2. The sex ratios of F2 converged into a few values, indicating that the sex-determining genotypes of the F1 full-sib sisters were also a few. This suggests that the sex in this snail is determined by a few genes rather than polygenes. Secondly, we developed genetic markers to study linkage with the putative sex-determining genes. We found >40 microsatellite loci, and developed four useful markers. These markers were repeatable in PCR, polymorphic and followed Mendelian segregation. We conducted fragment analyses in two populations (Kumamoto and Nara) with these markers. One of them showed significantly different frequencies between males and females in both populations ; it may be in the same linkage group as a sex-determining locus., url
  • 萌芽研究, 2005, 2006, 17657023, 不完全酵母カンジダで発見された接合型遺伝子は形態形成にどう関わるか。, 鈴木 孝仁; 岩口 伸一, 日本学術振興会, 科学研究費助成事業 萌芽研究, 奈良女子大学, 3000000, 3000000, Candida albicansは有性生殖世代を欠いているため不完全菌酵母に分類されており、通常二倍体の核相を有している。しかし、臨床分離株NUM51では、核相が二倍体の細胞と四倍体の細胞が混在し、細胞周期のG2遅滞を経て二倍体から四倍体に核相が増加する。四倍体の細胞では、S.cerevisiaeの減数第二分裂に相当する多極性の核内分裂を経て、二倍体に核相を減少させていることが連続超薄切片を用いた電子顕微鏡による紡錘体極の観察から明らかになった。C.albicansに関するゲノムプロジェクトが進展した結果、接合型遺伝子MTLが5番染色体上に座乗していることが報告された。NUM51株でも、この接合型遺伝子は異型接合(MTLa/MTLalpha)の状態で存在していることが判明した。そして、MTLaが座乗する5番染色体を喪失させたMTLalphaのみのヘミ接合体株や、MTLalphaを遺伝子破壊した株では、核相の変換がほとんど起こらず、合成培地での菌糸形成率も低下していた。さらに、接合型遺伝子の異型接合株では、核相が増加した細胞の出現と相まって抗真菌剤フルコナゾールに対する耐性が上昇することが明らかとなった。ところが、接合型遺伝子やそれらが座乗する染色体の一方を失った株では、核相が一定であることと相まってフルコナゾール耐性度に変化はみられなかった。これらの事実から、核相の変換にはMTL遺伝子座が異型接合の状態で存在することが必要であること、MTL遺伝子座が座乗する5番染色体には菌糸形成や抗真菌剤耐性に関わる遺伝子群も座乗し、この染色体性の変化(モノソミーとなったままか、あるいはその後に複製が起きて二染色体性になるか)や接合性の変化を通じて当該遺伝子量の変化がもたらされ、それらの結果として、形態形成の反応や抗真菌剤への耐性応答の違いという表現型が現れることが判明した。
  • Grant-in-Aid for Scientific Research (C), 2001, 2002, 13640664, The role of vitamin B1 as a regulator of yeast dimorphism (yeast-hypha conversion), SUZUKI Takahito; IWAGUCHI Shin-ichi, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Nara Women's University, 3600000, 3600000, The dimorphic transition from yeast to pseudohyphae in the petroleum-assimilating yeast Candida tropicalis occurs following the addition of ethanol to glucose semi-defined medium. Subtractive gene cloning was performed on the cDNA from the yeast-bowing control culture and on that from the ethanol-supplemented one (the ethanol culture). A homologue of Schizosaccharomyces pombe nmtl^+ or Saccharomyces cerevisiae THI5 was isolated from the cDNA fraction as a preferentially expressed gene for the ethanol culture. This homologue was tentatively called CtTHI5, since exogenous thiamine repressed its expression in C.tropicalis growth media. The ethanol culture showed biphasic pattern of growth phases and the expression of CtTHI5 occurred at the first growth phase. The supplementation of thiamine to the ethanol culture at the first phase was followed by repression of CtTHI5 expression and also delay of pseudohyphal growth and the occurrence of pseudomycelia in a stubby form with branched filaments. A CtTHI5 disruptant of this organism did not show thiamine auxotrophy and produced pseudohyphal filaments even in the control culture. The supplement of oxythiamine, an analog of thiamine, to the control culture was followed by the appearance of pseudohyphal filaments. Supplementation of valproic acid to the ethanol culture inhibited pseudohyphal growth, however, additional supplementation of thiamine partially cancelled the inhibition. These facts indicate that the participation of thiamine during the process of pseudohyphal growth in this organism.
  • Grant-in-Aid for Scientific Research (C), 1998, 2000, 10640650, Characterization of genes regulating dimorphic transition between yeast and pseudohyphal form., SUZUKI Takahito; KAMIHARA Teijiro; IWAGUCHI Shin-ichi, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), NARA WOMEN'S UNIVERSITY, 3600000, 3600000, Ethanol caused mycelial growth in the imperfect yeast Candida tropicalis Pk233. Cultivation with ethanol gave biphasic growth curves. During the first growth phase in the ethanol culture, there was an accumulation of swollen spherical yeast cells and after entering the second phase, pseudohyphal cells appeared, projecting from the swollen yeast cells. Subtractive cloning of genes was performed on the cDNAs of the ethanol culture, from which the cDNAs of the control cultur had been subtracted by hybridization. Isolated included Ctnmt1^+ homologous to S.pombe nmt1^+ oncoding the enzyme for thiamine biosynthesis and CtPP1 homologous to C.albicans CPP1 encoding tyrosine phosphatase.. Correlation was suggested of the process of ethanol-induced pseudomycelial formation with thiamine metabolism, since the elongation of the pseudohyphal growth was suppressed when exogenous thiamine was supplemented at the late stage of the first growth phase. Disruption of CtPP1 brought about the phenotype defective in pseudomycelial formation, suggesting the participation of MAP kinase cascade in the formation.
  • 奨励研究(A), 1999, 1999, 10770117, 病原性酵母カンジダの倍数性変換と染色体再配列を制御する遺伝子の解析, 岩口 伸一, 日本学術振興会, 科学研究費助成事業 奨励研究(A), 奈良女子大学, 1900000, 1900000, 日和見感染菌Candida albicansは通常二倍体だが、いくつか菌株では多倍数化した細胞の出現とそれに続く倍数性の減少すなわち倍数性変換が認められ、同時に染色体再編成が生じている。したがって倍数性変換がゲノムの変化を誘導する可能性を示唆している。倍数性変換を示す株の表現型はSps^-(suppresser of ploidy shift)で表される。それに対し、核相が一定である株の表現型はSps^+で表される。細胞融合実験からSps変異は劣性であることが示されているので、Sps^+株のゲノムDNAライブラリーをSps^-株に形質転換し、フロキシンB培地上で白い集落を形成すること、集落形態が滑面となること、増殖速度が速くなること、核の形態が一核となることという選択条件を設定しSPS遺伝子の単離を試みた。前年度に遺伝子破壊株であるSTN21U-1株に形質転換実験を行い、上記の選択方法に基づいてSps^+を示す13個の形質転換体を得た。本年度はその中からNo.115株をSPS遺伝子をもつ候補として選び出した。この株は細胞集団中にSTN21U-1株で観察される細胞よりも小さな細胞を生じる傾向があった。このNo.115株からプラスミドDNAを回収し、インサート部分をサブクローニングし、塩基配列を決定後に相同性検索を行ったところ、RAD5(REV2)遺伝子と高い相同性が見られた。Rad5タンパクはDNA修復タンパクのひとつであり、DNAへリカーゼであると考えられているが、詳しい機能については明らかにされていない。Rad5変異株では組み換えの頻度があがることが報告されているので、Sps^-株で染色体再編成が高頻度に起こるのは、RAD5遺伝子の変異に由来しているかもしれない。また、Sps^-株で高次倍数化するのは、RAD5の未知の機能が損なわれたためかもしれない。以上のことからRAD5がSPS遺伝子群の有力な候補の1つである可能性が考えられた。現在、RAD5遺伝子の機能解析を試みている。
  • Grant-in-Aid for Scientific Research (C), 1996, 1997, 08640846, Genetic regulation of dimorphic transition between yeast and hyphal form growth in the imperfect yeast, Candida tropicalis., SUZUKI Takahito; KAMIHARA Teijiro; IWAGUCHI Shin-ichi, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), NARA WOMEN'S UNIVERSITY, 2200000, 2200000, Ethanol caused mycelial growth in the imperfect yeast Candida tropicalis Pk233. Cultivation with ethanol gave biphasic growth curves. During the first growth phase in the ethanol culture, there was an accumulation of swollen spherical yeast cells, instead of the oblong ones observed in the control culture, followed by the appearance of spherical daughter cells in chains. During the second growth phase, hyphal cells appeared, projecting from the swollen yeast cells. Subtractive cloning of genes was performed on the cDNAs of the ethanol culture, from which the cDNAs of the control cultur had been subtracted by hybridization. Isolated genes specific for the process of hyphal formation included nmt1 homolog and URP2 homolog. Correlation was suggested of the process of ethanol-induced hyphal formation with thiamine metabolism, since the mycelial growth was abolished by addition of thiamine.
  • 奨励研究(A), 1996, 1996, 08770191, 病原性酵母カンジダ・アルビカンスの染色体組換えを制御するタンパク質の検索, 岩口 伸一, 日本学術振興会, 科学研究費助成事業 奨励研究(A), 奈良女子大学, 900000, 900000, 日和見感染菌である酵母C.albicansのゲノム全体に存在している反復配列RPS1は、染色体再配列の生じている部位に局在している。このような反復配列がゲノム上に存在している場合、組換えを制御するタンパク質が細胞中に存在しなければ、ランダムな組換えが生じ、ゲノムの不安定性を引き起こすと考えられる。本研究ではC.albicansの反復配列RPS1に結合する調節タンパク質をゲル・シフト法により探索した。ゲル・シフト法では、ポリアクリルアミド電気泳動において、DNA断片とタンパク質の複合体の移動度は遊離のDNA断片に比べて遅くなるという原理を利用する。RPS1配列から30〜100bpのDNA断片を調整、ラベルし、C.albicansからのタンパク質抽出液と反応させた。その結果、30bpのCOM29に対して強く結合するタンパク質と、RNAとして発現している領域のDNA断片に結合するタンパク質を検出できた。COM29配列に結合するタンパク質は、大過剰の未標識のプローブを加えた競合実験においてもシグナルが観察される事から配列特異性が非常に高く、かつ結合力がかなり大きい事が分かった。さらにサウス・ウエスタン法によりCOM29配列に結合するタンパク質の大きさを調べたところ、49、38、26.8kdの3つのポリペプチドが検出された。COM29配列はRPS1ユニット中に5個存在しているため、このタンパク質がRPS1内部、さらにはRPSクラスター全体をパッケージングすることにより、組換えの鋳型として機能させなくしている可能性が考えられる。現在、COM29配列をCNBr-sepharose 4Bに結合させたDNAアフィニティーカラムを作製し、結合タンパク質の単離を試みている。
  • 奨励研究(A), 1995, 1995, 07857019, 病原性酵母カンジダの染色体再配列に関わるRPS1配列とその転写反応, 岩口 伸一, 日本学術振興会, 科学研究費助成事業 奨励研究(A), 奈良女子大学, 900000, 900000, 本研究ではRPS1がRNAを介した組み換えに関与しているかを調べるために、まずC.albicansにおいて発現型RPS1の単離を試みた。発現型のRPS1相同配列は、1006、WO-1株ともに同じ大きさで、約1.3kbであった。発現量はアクチン遺伝子のそれとの比較から、2株とも同程度発現していると考えられる。本研究では新たな試みとして、マグネット・ビーズ上にcDNAライブラリーを構築を行った。これにより安定にライブラリーが保存することができ、さらに、マグネット上のcDNAを鋳型にしてPCR、あるいは、サブトラクションやDNA結合タンパク質などの検索が可能になる。RPS1配列の大きさは、2.1kbなので配列の全てがmRNAとして転写されているわけではない。そこで、RPS1配列のどの部分が発現されているかをPCR法により検討した。マグネット上のcDNAを鋳型として、RPS1由来のプライマーと(dT)_<18>プライマーによりPCRを行った。その結果、プライマー24279、24280、22531、13267とXhoI-(dT)18との組み合わせでPCR産物が得られた。このことは、発現型RPS1は少なくともnon-REP配列とCOM29配列を含むことを示している。REP配列については、その存在はこの実験からは定かではないが、COM29配列がオリジナルのRPS1配列では常にREP配列に接しているのでおそらく発現型RPS1においても存在しているものと推定された。また、COM29由来のプライマーである13267によるPCR産物の大きさは、最も大きいもので約1.2kbのものが認められるので5´末端側にCOM29由来の配列が存在すると予想される。それぞれのPCR産物のクローニングが現在行われている。
  • Grant-in-Aid for General Scientific Research (C), 1994, 1995, 06640865, MOLECULAR MECHANISM OF PLOIDY-SHIFT AND VARIATION OF COLONY MORPHOLOGY IN THE IMPERFECT YEASTS, SUZUKI Takahito; IWAGUCHI Shinichi, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for General Scientific Research (C), NARA WOMEN'S UNIVERSITY, 2100000, 2100000, Some strains of Candida albicans poroduce a proportion of the cell population with a higher ploidy than the rest in normal diploid state. This phenotype was named as Pld^-by the author. Ploidy-shift was observed between two different ploidy states. Pld-STN21 (arg4, Pld^-) was isolated from a weakly growing sector of a half-sectored colony, after UV-irradiation of STN14, an arg4 derivative of C.albicans CBS5736 and from the other normally growing sector, STN22 (arg4, Pld^+) was isolated. STN22, as well as its progenitor, CBS5736, showed a homogeneus colony size when plated out, but STN21 showed a characteristic heterogeneity of colony size on YPD plates at an early stage of incubation : two types of colonies, small ones and large ones, were observed. The chromosomes of these strains were separated out by PFGE.Some culture of STN21 showed the single band of chromosome 7, suggesting due to the occurrence of chromosome non-disjunction. The other culture of STN21 gave an extrachromosomal band, the size of which was larger than that of chromosome 7, and the loss of one of the two bands of chromosome 7. Southern blot hybridization experiments showed the existence of a SfiI fragment 7F,a central portion of chromosome 7, on the extrachromosomal band but the absence of a terminal SfiI fragment 7C.Protoplast fusion experiments showed, at least, two complementation groups of PLD,the function of which may stabilize both ploidy state and chromosome fidelity.


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