Search PubMed⌕ Search

Biomedical subjects

F Takaiwa

Publications and source records attributed to F Takaiwa.

At least 37 records · Page 2Linked to original sources
PubMed1997

Short inverted repeats function as hotspots of intermolecular recombination giving rise to oligomers of deleted plastid DNAs (ptDNAs).

We have determined the nucleotide sequences around the junction points of oligomeric-deleted ptDNAs possessing a head-to-head or tail-to-tail configuration from long-term cultured cell lines and albino plants. It was shown that DNA rearrangement occurred by direct fusion of deleted ptDNAs in an inverted orientation, which was linked by an asymmetrical sequence of 254-698 bp derived from either of the ptDNAs joined. It is notable that inverted repeats of 7-14 bp flank the asymmetrical sequences at each of the junction points. These features of the DNA sequence around the junction points are commonly observed in oligomeric ptDNA with a large-scale deletion regardless of the cell lines employed. It is suggested that the short inverted repeats are involved in the intermolecular recombination of ptDNA.

Base Sequence↗
PubMed1996

A 45-bp proximal region containing AACA and GCN4 motif is sufficient to confer endosperm-specific expression of the rice storage protein glutelin gene, GluA-3.

A 45-bp proximal region of the rice glutelin promoter (-104/-60) containing two putative cis-elements, the AACA motif and GCN4 motifs, was fused to a truncated CaMV 35S promoter (-90/+9; -90 delta 35S)/GUS. The 45-bp fragment specifically enhanced the promoter activity in endosperm tissue of transformed tobacco. A substitution mutation of the GCN4 motif reduced the promoter activity, whereas mutation of the AACA motif increased the activity in the embryo as well as in the endosperm. These results suggest that the GCN4 motif generally enhances the promoter activity but that the combination of the two motifs confers the endosperm specificity. Furthermore, the function of the two motifs was dependent on the orientation and/or distance from a G-box element in -90 delta 35S, suggesting that synergistic interaction between the factors that recognize those motifs and the G-box element is important for transcriptional regulation.

Base Sequence↗
PubMed1996

Characterization of common cis-regulatory elements responsible for the endosperm-specific expression of members of the rice glutelin multigene family.

Glutelin is the most abundant storage protein in rice, which is expressed specifically in the endosperm of maturing seed. Glutelin is encoded by about 10 genes per haploid genome, which are clearly divided into two subfamilies (GluA and GluB). Most of them are coordinately expressed during seed maturation in spite of the remarkable divergence in the 5'-flanking regions between members of two subfamilies. In order to identify the common regulatory mechanisms responsible for the endosperm-specific expression, various cis-regulatory elements in the 5'-flanking region of the glutelin GluB-1 gene were characterized by studying the expression of chimeric genes that consisted of the sequentially deleted or mutagenized promoter and a beta-glucuronidase (GUS) reporter gene in transgenic tobacco seeds. The essential cis-regulatory elements governing the spatially and temporally specific expression of the glutelin gene expression were located within the first 245 bp of the promoter region of the GluB-1 gene from the site of initiation of transcription. The AACA motif between positions -73 and -61 common to all the six genes for glutelin sequenced to date and is repeated between positions -212 and -200 is implicated in the seed-specific expression. The GCN4 motif between positions -165 and -158 and between positions -96 and -92 that is conserved at homologous sites in all the members of glutelin gene family is also involved in the seed-specific regulation. However, both are required for the high level of seed-specific expression, because deletion of the region containing one set of both elements or substitution mutation of the AACA or GCN4 motif substantially reduced the activity. As a whole, our results suggest the combinatorial interaction of the elements in regulation of the glutelin gene expression.

Base Sequence↗
PubMed1996

cis-regulatory elements responsible for quantitative regulation of the rice seed storage protein glutelin GluA-3 gene.

The 897 bp 5' flanking region of the rice storage protein glutelin gene (GluA-3) was analyzed to define cis-regulatory elements responsible for the seed specific expression by progressive 5' deletions and gain-of-function experiments using a truncated CaMV 35S promoter (-90/+9). These constructs were transcriptionally fused either to the firefly luciferase (LUX) or beta-glucuronidase (GUS) reporter gene and introduced into tobacco. It was shown that a 121 bp sequence between -437 and -317 from the transcriptional start site is important for the quantitative regulation of the GluA-3 gene expression. This region contained at least two functionally different cis-regulatory elements. One acts as a general positive element and the other is involved in a specific negative regulation in non-seed tissues.

Animals↗
PubMed1996

Structure and expression of two seed-specific cDNA clones encoding stearoyl-acyl carrier protein desaturase from sesame, Sesamum indicum L.

We have isolated two cDNA clones (CDES01) and 04) encoding stearoyl-acyl carrier protein desaturase (SACPD; EC 1.14.99.6) from immature sesame seeds, and have analyzed accumulation levels of the corresponding mRNAs at different stages and organs in sesame. Clone CDES01 contains an open reading frame coding for a 396-amino acid protein of 45 kDa. CDES04 encodes a partial sequence of 141-amino acids. Deduced amino acid sequences of both clones exhibit a high identity to those of other plant SACPD cDNAs. Northern blots probed with CDES01 and CDES04 indicate that both messages accumulate in a seed-specific manner with a peak at 21 days after anthesis. However, expression patterns also indicate that regulation between CDES01 and CDES04 are slightly different. The CDES01 message accumulates at a low level in young leaves in addition to seeds, whereas accumulation of the RNA transcript corresponding to CDES04 is restricted to seeds. This observation implies the presence of at least two isozymes of SACPD having overlapping but slightly distinct functions in sesame.

Amino Acid Sequence↗
PubMed1995

Differential display identifies developmentally regulated genes during somatic embryogenesis in eggplant (Solanum melongena L.).

Changes in gene expression patterns during early somatic embryogenesis of eggplant (Solanum melongena L.) were characterized by means of differential display. Eight products of polymerase chain reaction (PCR) derived from newly expressed mRNAs after four days of culture were identified and cloned. One clone, pTM002, was found to contain a 416 bp insert and identical to the proximal arbitrary primer at both ends. Based on the terminal sequences, reverse-transcription PCR (RT-PCR) was carried out to monitor the expression level of pTM002. The results indicated that the message of pTM002 was increased to correlate with the intensities obtained in the differential display. The significance of this method in investigation of differentially expressed genes is also discussed.

Base Sequence↗
PubMed1994

Molecular changes of organelle DNA sequences in rice through dedifferentiation, long-term culture, or the morphogenesis process.

Callus-specific rearranged DNA in rice (Oryza sativa L.) was isolated by in-gel reassociation procedure. Southern hybridization experiments revealed that some clones were amplified significantly in primary callus induced from scutellum tissue. Rapid amplification of these clones was observed within 2 days after plating seeds onto callus-induction medium containing 2,4-D. NAA gave no significant effect on DNA amplification event. Colony formation process from isolated protoplasts and plant regeneration process from callus showed clone-specific and process-specific fluctuation patterns of copy number. Sequence analysis of the clones suggested that most of the clones were originated from organelle DNA. Comparison of copy number fluctuation pattern of organelle functional genes with that of the clones suggested multiformity and/or construction-specific amplification of organelle DNA.

Adenosine Triphosphatases↗
PubMed1991

Analysis of the 5' flanking region responsible for the endosperm-specific expression of a rice glutelin chimeric gene in transgenic tobacco.

The 5' upstream region of the rice storage protein type II glutelin gene was examined for its regulatory function in transgenic tobacco. Chimeric genes containing 5' flanking regions of the glutelin gene transcriptionally fused to the beta-glucuronidase (GUS) reporter gene were introduced into the tobacco genome by Agrobacterium tumefaciens-mediated gene transfer. The chimeric genes were expressed specifically in developing seeds, as opposed to leaves and stems, of the transgenic tobacco. Histochemical analysis revealed that the GUS activity was restricted to the endosperm tissue. A deletion series of the 5' flanking region was created from position -1329 to -74 relative to the transcriptional initiation site and similarly examined in transgenic tobacco. Measurement of GUS activity of the seeds from the transgenic plants bearing the chimeric genes indicated that the region between positions -441 and -237 was required for the temporal and endosperm-specific expression of the GUS activity in tobacco. RNA analysis by northern blotting confirmed the importance of the -441 to -237 region. Addition of up to 888 bp to the -441 deletion resulted in little increase in GUS activity, although all constructs expressing the GUS gene showed a similar tissue and temporal regulation pattern.

Base Sequence↗
PubMed1991

Sequence of three members and expression of a new major subfamily of glutelin genes from rice.

Three members have been isolated of an additional glutelin gene subfamily, named subfamily B, consisting of about five members per haploid rice genome. Restriction fragment length polymorphism analysis showed major differences between Japonica and Indica lines, indicating the divergence of the subfamily since the split between the two varieties. While corresponding exons of the subfamily B showed 80 to 88% nucleotide sequence homology, those exons were only 60-65% homologous to those of the glutelin A subfamily, distinguishing them from the subfamily A. Intron position and derived polypeptide structure, in addition to the nucleotide sequence, confirm the subfamily B members as glutelins. Analysis of RNA from seeds of different stages of development showed that the subfamily B members were expressed at the same time as those of subfamily A, demonstrating coordinated regulation of the two subfamilies.

Amino Acid Sequence↗
PubMed1991

Genomic DNA sequences of two new genes for new storage protein glutelin in rice.

A new cDNA and two genomic genes encoding the rice storage protein glutelin were isolated and sequenced. The nucleotide sequence of one gene (GluA-3) was completely identical with that of the new cDNA identified here, and the other (GluA-4) was a pseudogene. These glutelin genes were closely related to each other, and belonged to the subfamily A containing the type I (GluA-1) and II (GluA-2) glutelin genes. The Northern blot analysis, using synthetic oligonucleotide specific to the GluA-3 gene as a probe, showed that this gene was expressed earlier than other glutelin genes during seed maturation.

Amino Acid Sequence↗
PubMed1990

Interaction of an immature seed-specific trans-acting factor with the 5' upstream region of a rice glutelin gene.

The 5' flanking region of a glutelin gene was analyzed for interactions with nuclear proteins from immature rice seed. The specific region between positions -272 and -99 was shown to interact with nuclear proteins from immature seeds, but not with those of leaves and roots. Methylation interference experiments revealed that one factor interacted with a specific sequence element between positions -130 and -120 relative to the transcriptional start site. The sequence specificity of this DNA-protein interaction was confirmed by competition experiments using synthetic oligonucleotides. By using a synthetic oligonucleotide as a probe it was also shown that the binding activity was closely correlated with the mRNA levels of this gene during seed maturation.

Base Sequence↗
PubMed1989

[Rice genomic DNA].

Explore the source record for details and available documents.

Cloning, Molecular↗
PubMed1987

Variable copy number DNA sequences in rice.

We have cloned two types of variable copy number DNA sequences from the rice embryo genome. One of these sequences, which was cloned in pRB301, was amplified about 50-fold during callus formation and diminished in copy number to the embryonic level during regeneration. The other clone, named pRB401, showed the reciprocal pattern. The copy numbers of both sequences were changed even in the early developmental stage and eliminated from nuclear DNA along with growth of the plant. Sequencing analysis of the pRB301 insert revealed some open reading frames and direct repeat structures, but corresponding sequences were not identified in the EMBL and LASL DNA databases. Sequencing of the nuclear genomic fragment cloned in pRB401 revealed the presence of the 3'rps12-rps7 region of rice chloroplast DNA. Our observations suggest that during callus formation (dedifferentiation), regeneration and the growth process the copy numbers of some DNA sequences are variable and that nuclear integrated chloroplast DNA acts as a variable copy number sequence in the rice genome. Based on data showing a common sequence in mitochondria and chloroplast DNA of maize (Stern and Lonsdale 1982) and that the rps12 gene of tobacco chloroplast DNA is a divided gene (Torazawa et al. 1986), it is suggested that the sequence on the inverted repeat structure of chloroplast DNA may have the character of a movable genetic element.

Base Sequence↗