Researchers Database

IWAGUCHI Shin-ichi

    Faculty Division of Natural Sciences Research Group of Biological Sciences Associate Professor
Last Updated :2021/06/02



  • 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)


  • 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


  • 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

Published Papers

  • 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

    Nov. 2020, Microbiology Resource Announcements, in press

    Scientific journal

  • 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

    Oct. 2020, Microbiology Resource Announcements, 9 (41)

    Scientific journal

  • 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, Venus, 76, 79 - 85

    Scientific journal

  • 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, 生物工学, 87 (7), 356 - 357

    Scientific journal

  • ナラノヤエザクラの花からの有用な酵母の分離及びそれを使った清酒の開発

    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, 奈良県工業技術センター 研究報告, (35), 35 - 38

    Research institution

  • 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., INFORMA HEALTHCARE, 2008, MEDICAL MYCOLOGY, 46 (7), 655 - 663, doi;web_of_science

    Scientific journal

  • 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., JOHN WILEY & SONS LTD, Jun. 2004, YEAST, 21 (8), 619 - 634, doi;web_of_science

    Scientific journal

  • 病原真菌データベース・Pathogenic Fuugi Database (PFDB)の公開

    IWAGUCHI Shin-ichi

    2002, 臨床検査, (Vol.46), No.8:919-924

  • 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., JOHN WILEY & SONS LTD, Aug. 2001, YEAST, 18 (11), 1035 - 1046, web_of_science

    Scientific journal

  • [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

    4, 2001, Nihon Ishinkin Gakkai zasshi = Japanese journal of medical mycology, 42, 243 - 251, doi;pubmed

  • 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, PLANT MORPHOLOGY, 13 (1), 2 - 10

    Scientific journal

  • 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., JOHN WILEY & SONS LTD, Mar. 2000, YEAST, 16 (5), 411 - 422, web_of_science

    Scientific journal

  • 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., SOC GENERAL MICROBIOLOGY, Feb. 1998, MICROBIOLOGY-UK, 144, 403 - 410, web_of_science

    Scientific journal

  • A Search for Specific Genes Working on the Process of Mycelial Growth in Candida tropicalis

    Suzuki T; Imanishi Y; Iwaguchi S; Kamihara T

    2, 1998, Japanese Journal of Medical Mycology, 39, 61 - 65, doi;pubmed

    Scientific journal



    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., AMER SOC MICROBIOLOGY, Sep. 1994, JOURNAL OF CLINICAL MICROBIOLOGY, 32 (9), 2253 - 2259, web_of_science

    Scientific journal



    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., AMER SOC MICROBIOLOGY, Jul. 1994, JOURNAL OF BACTERIOLOGY, 176 (13), 3851 - 3858, web_of_science

    Scientific journal



    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., SOC GENERAL MICROBIOLOGY, Jul. 1993, JOURNAL OF GENERAL MICROBIOLOGY, 139, 1409 - 1415, web_of_science

    Scientific journal



    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., SOC GENERAL MICROBIOLOGY, Sep. 1992, JOURNAL OF GENERAL MICROBIOLOGY, 138, 1893 - 1900, web_of_science

    Scientific journal



    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., SOC GENERAL MICROBIOLOGY, Jun. 1992, JOURNAL OF GENERAL MICROBIOLOGY, 138, 1177 - 1184, web_of_science

    Scientific journal



    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., SOC GENERAL MICROBIOLOGY, Nov. 1991, JOURNAL OF GENERAL MICROBIOLOGY, 137, 2531 - 2538, web_of_science

    Scientific journal



    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., SOC GENERAL MICROBIOLOGY, Dec. 1990, JOURNAL OF GENERAL MICROBIOLOGY, 136, 2433 - 2442, web_of_science

    Scientific journal

Books etc

  • 深在性真菌症Q&A

    IWAGUCHI Shin-ichi (, Range: 分担)

    医薬ジャーナル社, Mar. 2006, 44-45

  • 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?

    IWAGUCHI Shin-ichi

    メジカルセンス, 1997, 103-106頁

  • Molecular Biology of pathogenic fungi : Laboratory manual[Chromosome isolation and digestion]

    IWAGUCHI Shin-ichi

    Toles press, 1994, 91-94頁

  • 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」

    IWAGUCHI Shin-ichi

    菜根出版, 1993

Teaching Experience

  • Genetics lab (Nara University of Education)

  • Genetics (Nara University of Education)

Association Memberships

  • 日本農芸化学会

  • 日本生物工学会

  • 日本細菌学会

  • 日本医真菌学会

  • 酵母研究会

  • American Society for Microbiology

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