Takahiro Taguchi

Cloning of a Putative Ligand for the T1/ST2 Receptor

T1/ST2 is a receptor-like molecule homologous to the type I interleukin-1 receptor. Despite this sequence similarity, we have been unable to demonstrate binding of T1/ST2 to any of the three interleukin-1 species. In searching for a ligand for T1/ST2, we have cloned a cell surface protein to which it binds. This protein is unable to initiate signal transduction by the T1/ST2 receptor in several in vitro assays.

Integration of human herpesvirus 6 in a Burkitt's lymphoma cell line.

Human herpesvirus 6 (HHV‐6) genome has been found in several human lymphoid malignancies, but configuration of the HHV‐6 genome has not been well delineated. We established the HHV‐6‐positive, Epstein‐Barr virus‐negative Burkitts lymphoma cell line Katata. In this study we investigated the status of the HHV‐6 genome in Katata cells. Neither linear nor circular HHV‐6 DNA was detected by Gardella gel analysis. The fluorescence in situ hybridization technique enabled us to directly visualize the integrated HHV‐6 DNA at the single‐cell level. Only one integrated site of viral DNA was detected in metaphase chromosomes and it was preferentially located at the long arm of chromosome 22 (22q13). Treatment of the cells with 12‐O‐tetradecanoyl‐phorbol‐13‐acetate (TPA) or with calcium ionophore A23187 led to induction of the HHV‐6 immediate‐early gene as well as the late gene. Sodium n‐butyrate also gave rise to expression of the HHV‐6 genes. The TPA inducibility was synergistically enhanced when combined with A23187 or n‐butyrate. Our study provides, for the first time, an in vitro model system of latent HHV‐6 infection whose genome is integrated into host DNA of lymphoma cells.

Chromosomal localization of a gene, GFI1, encoding a novel zinc finger protein reveals a new syntenic region between man and rodents

The Gfi1 gene encodes a zinc finger protein which binds DNA and is involved in transcriptional regulation. Gfi1 was assigned to the central portion of mouse Chr 5 by interspecific backcross mapping and to human chromosome band 1p22 and rat chromosome band 14p22 by fluorescence in situ hybridization (FISH). Comparative mapping data presented here describes a new syntenic region between man and rodents.

Mapping of AKT3, encoding a member of the Akt/protein kinase B family, to human and rodent chromosomes by fluorescence in situ hybridization

Previously, a rodent cDNA encoding the third member of the Akt/PKB family of serine/threonine kinases was cloned. We have now cloned the human homolog of this cDNA, and we have used this clone to map the AKT3 gene to human chromosome 1q44 by fluorescence in situ hybridization (FISH). We have also mapped the rodent homologs of AKT3 to rat chromosome 13q24→q26 and mouse chromosome 1H4–6 by FISH.

Identification of integrated human herpesvirus 6 DNA in early pre-B cell acute lymphoblastic leukemia

Identification of integrated human herpesvirus 6 DNA in early pre-B cell acute lymphoblastic leukemia

Combined chromosome microdissection and comparative genomic hybridization detect multiple sites of amplified DNA in a human lung carcinoma cell line

Chromosome microdissection‐fluorescence in situ hybridization and comparative genomic hybridization (CGH) were performed in parallel to identify the native location of amplified DNA in a human non‐small cell lung cancer (NSCLC) cell line exhibiting a homogeneously staining region (hsr) and double minutes (dmin). The native locations of microdissected DNA from the hsr and dmin were 7p12‐13 and 8q24, respectively. Southern analysis revealed coamplification of EGFR (7p12) and MYC (8q24). CGH detected amplification of DNA not only from 7p12‐13 and 8q24, but also from 9p24 and 10q22. Genes Chromosomes Cancer 20:208–212, 1997.

Relationships between Schistosoma malayensis and other Asian schistosomes deduced from DNA sequences.

At least three Schistosoma species can infect humans in South-East Asia. The most widespread of these is S. japonicum Katsurada, 1904 which may represent a species complex and occurs in many countries including China, Japan and the Philippines. The second species is S. mekongi Voge, Bruckner and Bruce, 1978 which is endemic to a small area near the junction of Laos, Cambodia and Thailand. Most recently described is S. malayensis Greer, Ow-Yang and Yong, 1988 from a restricted area of peninsular Malaysia. This is primarily a parasite of rats but has also been found in people Davis, on the basis of snail intermediate host phylogeny and biogeography, proposed that S. malayensis and S. mekongi are sister taxa relative to S. japonicum. The three studies on allozymes among these taxa also support this hypothesis.

A new human synovial sarcoma cell line, HS-SY-3, with a truncated form of hybrid SYT/SSX1 gene

Recent cytogenetical and molecular studies have indicated that synovial sarcoma harbors a t(X;18)(p11.2;q11.2) translocation, resulting in the formation of a hybrid SYT/SSX (SSX1 or SSX2) gene. We newly established a human cell line, HS‐SY‐3, from a synovial sarcoma. HS‐SY‐3 cells were shown to harbor the pathognomonic t(X;18)(p11.2;q11.2) translocation by chromosome analysis but not to exhibit the classical hybrid SYT/SSX transcripts induced by this translocation, using RT‐PCR. To determine the reason for this discrepancy, we analyzed cDNA from HS‐SY‐3 cells, as well as the original sarcoma tissue by the rapid amplification of cDNA 3′ end assay, and found that the chimaeric cDNA was 240 bp shorter than the previously established SYT/SSX1 cDNA due to truncation of the 3′ side of SSX1. The HS‐SY‐3 cells should be useful for future functional studies of the SYT/SSX chimeric gene. Int. J. Cancer 82:459–464, 1999.

Localization of the interferon-α gene cluster to rat chromosome bands 5q31→q33 by fluorescence in situ hybridization

The chromosomal location of the rat interferon-α (IFNA) gene cluster was determined by fluorescence in situ hybridization. The fluorescent signals were localized to 5q31→q33. A previous report, using

Genomic differentiation of 18S ribosomal DNA and beta-satellite DNA in the hominoid and its evolutionary aspects.

The chromosome localization of two human multisequence families, rDNA and β-satellite (β-sat) DNA, was determined in humans and apes using double color fluorescence in-situ hybridization. Both DNA probes showed a distinct hybridization pattern with species-specific variations in hominoids. The stepwise differentiation of the integration, amplification, multilocalization, and reduction of the DNAs were observed interspecifically through the seven species examined. The stepwise events allowed us to trace back a phylogenetic divergence of the hominoid at the cytogenetic level. The manifestation of the events revealed that variations of the Y chromosome and acrocentric autosomes were synapomorphic characters in the divergence and those of metacentric autosomes were autapomorphic characters. Multilocalization of rDNA in the hominoid could also be interpreted as a result of translocations in terms of hetero-site crossover followed by a centric fission and formation of an acrocentric chromosome. Based on the observed rearrangements of rDNA and β-sat DNA, we propose the following chromosomal phylogenetic divergence order in hominoids: gibbon-siamang-orangutan-gorilla-human-chimpanzee-bonobo. Our data provide additional evidence that evolution of the hominoid can be effectively studied using cytogenetic approaches.