ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • gene family  (3)
  • Springer  (3)
  • 1
    ISSN: 1573-5028
    Keywords: alfalfa ; antisense ; gene family ; glutamine synthetase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Glutamine synthetase (GS) catalyzes the ATP-dependent condensation of NH3 with glutamate to produce glutamine. In plants GS is an octameric enzyme and is located either in the cytoplasm (GS1) or in the chloroplast (GS2). Two distinct classes of GS1 genes with unique 3′-untranslated region (3′UTR) have been identified in alfalfa. We have demonstrated that the two classes exhibit differential expression pattern in the different plant organs suggesting different functional roles for the different isozymes. To determine the functional significance ofss the two classes of GS1 genes in alfalfa, we have utilized antisense gene constructs aimed specifically at the 3′UTR of the two GS1 genes and introduced them individually into alfalfa. Our data show that the gene constructs are effective in lowering the corresponding transcript level very effectively though there were organ-specific differences in the level of reduction. No transcript corresponding to the antisense gene construct was detected in any of the alfalfa transformants though they accumulated to significant levels in transgenic tobacco containing the same construct. This suggests that the antisense transcript was not stable in the presence of the homologous target sequence. Transgenic alfalfa with up to 80% reduction in the transcript level corresponding to each gene class, however, showed no reduction in GS activity or GS1 polypeptide level. The results suggest that GS1 mRNA levels are not rate-limiting for GS1 polypeptide synthesis and that GS1 levels are controlled both at the transcriptional and translational/post-translational level.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-5028
    Keywords: soybean ; nodulin ; gene organization ; hybrid select translation ; gene family ; developmental regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A gene encoding for nodulin-16 (N-16) was isolated from a soybean genomic library. Nucleotide sequence analysis of the cDNA and the genomic clone of N-16 indicated that the coding region of this gene is 330 bp long and is interrupted by a single intron of 494 bp. The coding region of the N-16 gene shows a high degree of localized sequence similarity with the coding sequence of soybean nodulin-24 (N-24). Sequence similarity between the two genes is limited to the coding region of 90 bp in the first exon and the first 54 bp in the second exon of the N-16 gene which is repeated as the 2nd, 3rd, and 4th exons in the N-24 gene. The N-24 gene has been postulated to be a result of repeated duplication of an insertion element consisting of the 54 bp exon and the flanking intron sequences. In the absence of sequence similarity in the regions flanking the 54 bp sequence between the N-16 and N-24 genes, the N-16 gene does not appear to be the ancestral gene. Both N-16 and N-24 have a similar hydrophobic amino terminal end suggesting that N-16 like N-24 is targeted to the peribacteroid membrane. Southern analysis of soybean genomic DNA shows the presence of other related sequences to the N-16 gene, one of which is found to be closely linked to it. Analysis of the temporal accumulation of the N-16 transcripts during nodule development in effective and ineffective nodules suggests that N-16 and related genes might differ from leghemoglobin and some other late nodulin genes in their mechanism of regulation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-5028
    Keywords: cDNA sequence ; gene family ; glutamine synthetase ; soybean nodules ; cotyledons ; hybrid-select translation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have characterized two sets of cDNA clones representing the glutamine synthetase (GS) mRNA in soybean nodules. Using the 3′-untranslated regions of a representative member of each set, as gene member(s) specific probes, we have shown that one set of the GS genes are expressed in a nodule-specific manner, while the other set is expressed in other tissues, besides the nodules. The nodule-specific GS genes are expressed in a developmentally regulated manner in the nodules, independent of the onset of nitrogen fixation. The other class of GS genes is expressed constitutively in all tissues tested, but its expression level is dramatically enhanced in nodules following onset of N2 fixation. The latter set of genes is also expressed in cotyledons of germinating seedlings in a developmentally regulated manner. Analysis of hybrid select translation products and genomic Southern blots suggests that multiple gene members in each class are expressed in the nodules.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...