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491.
The sequences of ITS regions in 30 species and two groups of the genusPythium were resolved. In the phylogenetic trees, the species were generally divided into two clusters, referred to here as the F
and S groups. The species in the two groups correspond in terms of their sporangial morphology, with the F group being filamentous/lobulate
and the S group being spherical. Genetic divergence within the F group was lower than that within the S group. Other morphological
characteristics such as oogonial structure and sexual nature appeared to be unrelated to the groupings in these trees. An
alignment analysis revealed common sequences to all the species and arrangements specific to each F or S group. It was found
that the ITS region was a good target in designing species-specific primers for the identification and detection ofPythium species. In the tree based on 5.8S rDNA sequences, oomycetes are distantly related to other fungi but separated from algae
in Chromista. 相似文献
492.
Koichi Hiratsuka Wataru Yoshida Mitsuo Hayakawa Hisashi Takiguchi Yoshimitsu Abiko 《FEMS microbiology letters》1996,138(2-3):167-172
Abstract A sensitivity assay for Porphyromonas gingivalis based upon the polymerase chain reaction (PCR) was developed. A 426-bp sequence, including a Dra I- Hinc II DNA fragment (278 bp) encoding the 40-kDa outer membrane protein of the P. gingivalis gene was amplified. PCR products were obtained from chromosomal DNAs of the P. gingivalis strains tested but not from those of other oral microorganisms. The lower limit of template DNA detection was 10 pg with 30 cycles and 100 fg with 40 cycles of PCR by agarose gel electrophoresis. The PCR products were hybridized with Dra I- Hinc II DNA fragment internal to the PCR primers regions used. The lower limit of hybridization detection was 10 pg and 10 fg of template DNA with 30 and 40 cycles of PCR, respectively. These results demonstrated the simplicity, rapidity and specificity of the procedure, as well as the use of the Dra I- Hinc II DNA fragment in the identification of P. gingivalis . 相似文献
493.
Itoh Takeshi; Aiba Hiroji; Baba Tomoya; Hayashi Kouji; Inada Toshifumi; Isono Katumi; Kasai Hiroaki; Kimura Shigenobu; Kitakawa Madoka; Kitagawa Masanari; Makino Kozo; Miki Takeyoshi; Mizobuchi Kiyoshi; Mori Hirotada; Mori Tomoko; Motomura Kouji; Nakade Shinsuke; Nakamura Yoshikazu; Nashimoto Hiroko; Nishio Yoshitaka; Oshima Taku; Saito Noriko; Sampei Gen-ichi; Seki Yasushi; Sivasundaram Suharnan; Tagami Hideaki; Takeda Jun-ichi; Takemoto Keiko; Wada Chieko; Yamamoto Yoshihiro; Horiuchi Takashi 《DNA research》1996,3(6):379-392
The 465,813 base pair sequence corresponding to the 40.150.0min region on the genetic map of Escherichia coli K-12 (W3110)was determined. Analysis of the sequence revealed that thisregion contained at least 466 potential open reading frames,of which 187 (40%) were previously reported, 105 (23%) werehomologous to other known genes, 103 (22%) were identical orsimilar to hypothetical genes registered in databases, and theremaining 71 (15%) did not show a significant similarity toany other gene. At the 45.246.0 min region, we founda very large cluster of about 30 genes, whose functions areinvolved in the biosynthesis of polysaccharides as the componentsof outer membranes. In addition, we identified anew asn-tRNAgene, designated asnW, between the asnT and asnU genes and anew lysogenic phage attachment site as the cis-element. 相似文献
494.
Wafa Al-Kurdi-Norimine Fumiko Ochikubo Yasushi Ami Kazuya Yamanouchi Chieko Kai 《American journal of primatology》1994,33(4):301-308
Optimal conditions for the mitogen-induced proliferation of T and B lymphocytes of cynomolgus monkeys were determined. The T cell mitogens concanavalin A and phytohemagglutinin, at concentrations of 1.25–10 μg/ml and 1.25–10 μg/ml, respectively, and the T and B cell mitogen pokeweed mitogen, at concentrations of 0.2–10 μg/ml, induced high lymphoproliferative responses, the average stimulation index (SI) being 34–93. Since suitable mitogens have not been reported for monkey B cells, we tested three types of lipopolysaccharide (LPS): two derived from Escherichia coli—one extracted with phenol and one extracted with trichloroacetic acid (TCA); and one derived from Salmonella typhimurium, extracted with phenol. All three LPS had a high mitogenic effect for monkey lymphocytes, with SI of 2.3–6.4. The highest response was observed for 25 μg/ml of Salmonella LPS, and the addition of trypsin to the culture augmented the proliferative response of low or non-responder lymphocytes. © 1994 Wiley-Liss, Inc. 相似文献
495.
Selenoguanine- and selenoguanosine-platinum(II) complexes were synthesized, and their atitumor activities against L1210 in mice and against in vitro tissue culture system were studied. These compounds exhibited antitumor activity of medium strength and showed very low toxicity. The effect of the SeG-Pt (II) complex in mice was retained longer than that of the parent compound SeG because the SeG-Pt (II) complex very slowly released SeG into blood. 相似文献