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K Saigo

Publications and source records attributed to K Saigo.

At least 145 records · Page 8Linked to original sources
PubMed1986

Structural variations in the Drosophila retrotransposon, 17.6.

More than 21 members of 17.6, a Drosophila retrotransposon, were isolated and their possible structural changes were examined by restriction mapping, blot hybridization, heteroduplex analysis and nucleotide sequence determination of long terminal repeats (LTRs). At least 7 members were found to suffer with terminal or internal long deletions. No pair of LTRs having an identical nucleotide sequence was found either within an element or between elements. Although an initiation site for the presumable genome-sized transcript of 17.6, a potential substrate for reverse transcription on translocation, was identified within the left-hand LTR, our results as a whole support the notion that the majority of 17.6s have continued to reside for a long period of time at their present chromosomal loci and hence the rate of translocation of 17.6 is very low.

Animals↗
PubMed1986

Identification of genes for reverse transcriptase-like enzymes in two Drosophila retrotransposons, 412 and gypsy; a rapid detection method of reverse transcriptase genes using YXDD box probes.

Using synthetic oligonucleotides corresponding to the amino acid sequences best conserved among retroviral reverse transcriptases, we developed a rapid method to detect cloned DNA fragments with the genes for reverse transcriptases. By this technique followed by nucleotide sequence determination, nucleotide sequences coding for reverse transcriptase-like enzymes were identified in two Drosophila retrotransposons, gypsy and 412. Our sequence analysis suggested that there are at least two major groups of retrotransposons in Drosophila with respect to putative reverse transcriptases and both gypsy and 412 belong to a category of retrotransposons which have putative reverse transcriptases very similar in amino acid sequence to the counterpart of Moloney murine leukaemia virus, a typical mammalian retrovirus.

Amino Acid Sequence↗
PubMed1986

Identification and nucleotide sequence determination of a potential primer tRNA for reverse transcription of a Drosophila retrotransposon, 297.

Drosophila retrotransposons have been shown to have genes for enzymes similar to the reverse transcriptase of retroviruse. They may possibly be involved in genome replication on translocation (15). Identification was made of a primer tRNA for the putative reverse transcription of a Drosophila retrotransposon, 297, and its genomic counterparts using a homology to the putative primer binding site of 297. Our nucleotide sequence analysis indicated a species of Drosophila serine tRNA to have two distinct properties similar to those characteristic of retroviral primer tRNA: its 3'terminal 18 nucleotides are exactly complementary to the putative primer binding site of 297 and its 19th base from the 3' end is modified. These results appear to support the notion stated above and suggest this serine tRNA to be the most likely candidate for a potential primer tRNA of 297.

Animals↗
PubMed1986

Complete nucleotide sequence and genome organization of a Drosophila transposable genetic element, 297.

The complete nucleotide sequence of 297, a Drosophila copia-like transposable element, was determined and compared with those of other similar Drosophila elements and mammalian retrovirus proviruses. It was found that 297 contains three long open reading frames, comparable in sizes and locations with gag, pol, and env genes in the proviruses of replication-competent retroviruses in vertebrates. The first and second open reading frames of 297 exhibit sequence homologies to gag and pol, respectively, of Moloney murine leukaemia virus. In particular, as with 17.6, another Drosophila copia-like element, the second open reading frame of 297 was shown to be very similar in its entire organization to the retroviral pol gene and to consist of three enzymatic domains. By contrast, no appreciable homology was found between the third open reading frame of 297 and the retroviral env gene. It is also suggested that 297 and 17.6 are a peculiar pair of copia-like elements recently diverged from a common progenitor.

Amino Acid Sequence↗
PubMed1986

Neutrophils with ring-shaped nuclei in chronic neutrophilic leukemia.

A significant incidence of neutrophils with ring-shaped nuclei was observed in all of four patients with chronic neutrophilic leukemia. The present data may give further support for the view that chronic neutrophilic leukemia is not a reactive disorder but a rare form of myeloproliferative disorder. It seems possible that this phenomenon can be used as a marker for abnormal granulopoiesis in human diseases.

Cell Nucleus↗
PubMed1986

[Adult T cell leukemia accompanied by marked swelling of the left thigh].

A patient with adult T cell leukemia (ATL) whose chief complaint was marked swelling of left thigh is reported. A 72-year-old woman was diagnosed as having ATL based on a high titer of anti-ATLA antibody and abnormal lymphocytes with convoluted nuclei. Computed tomography revealed swelling of her left thigh and a large low-attenuation mass in its muscles. Aspirate from her thigh contained many abnormal cells. Though chemotherapy reduced the swelling for two weeks, she had a relapse and died. This is the first case of ATL having such an onset reported in Japan.

Aged↗
PubMed1985

Close structural resemblance between putative polymerase of a Drosophila transposable genetic element 17.6 and pol gene product of Moloney murine leukaemia virus.

We have made a computer-assisted search for homology among polymerases or putative polymerases of various viruses and a transposable element, the Drosophila copia-like element 17.6. The search revealed that the putative polymerase (second open reading frame) of the copia-like element 17.6 bears close resemblance in overall structural organization to the pol gene product of Moloney murine leukaemia virus (M-MuLV): they show significant homology to each other at both the N- and C-terminal portions, suggesting that the 17.6 putative polymerase carries two enzymatic activities, related to reverse transcriptase and DNA endonuclease. The putative polymerase of cauliflower mosaic virus (CaMV) shows striking homology with the putative polymerase of 17.6 over almost its entire length, but it lacks the DNA endonuclease-related sequence. Furthermore, it was shown that the N-terminal ends of the M-MuLV pol product and the CaMV and 17.6 putative polymerases exhibit strong sequence homology with the gag-specific protease (p15) of Rous sarcoma virus (RSV) as well as the amino acid sequence predicted from the gag/pol spacer sequence of human adult T-cell leukaemia virus (HTLV). These p15-related sequences contain a highly conserved stretch of amino acids which show a close similarity with sequences around the active site amino acids Asp-Thr-Gly of the acid protease family, suggesting that they have an activity similar to acid protease. On the basis of the alignment of reverse transcriptase-related sequences, a dendrogram representing phylogenetic relationships among all the viruses compared together with 17.6 was constructed and its evolutionary implication is discussed.

Amino Acid Sequence↗
PubMed1984

An economic "power supply" using a diode for agarose and polyacrylamide gel electrophoresis.

Gel electrophoresis using agarose and polyacrylamide is a technique widely used for the separation of DNA and protein of various molecular sizes. This type of electrophoresis involves use of a rather expensive dc power supply composed of a complicated circuit. A simple circuit consisting of a single diode was designed, which can be used as a substitute for the conventional power supply. There are no appreciable differences in the so-obtained electrophoretic patterns. This simple, economic system is expected to be applied for use in laboratory, industrial, educational, and clinical facilities.

DNA↗