ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Somatic embryogenesis and plantlet regeneration in the soybean Glycine max (1985)
    Springer
    Plant cell reports 4 (1985), S. 344-347 
    Details
    ISSN: 1432-203X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A tissue culture procedure for the regeneration of somatic embryos and plantlets from somatic cells of the soybean Glycine max is described. Bean pods of soybean cv. TGM119 were immersed in liquid nitrogen for 20 minutes. Young embryos were excised from the immature seeds and cultured to form calli. Calli grown from the young embryos were incubated in liquid culture for two weeks. The liquid suspension culture was filtered to obtain single cells. The soybean cells were cultured for one month in a liquid medium in hanging drop cultures for development into proembryoids. The proembryoids were maintained on a solid growth medium for 40 days. The resultant callus tissue was transferred into MS media containing selected combinations and concentrations of 2,4-Dichlorophenoxyacetic acid, Naphthaleneacetic acid, Kinetin, Benzyladenine and Indoleacetic acid. In the presence of Benzyladenine (0.2 mg/l) and Indoleacetic acid (0.01 mg/l), globular and heart shaped somatic embryos were formed on the surface of the calli. Calli containing somatic embryos were transferred into liquid medium and incubated under low light conditions. After six months further incubation, more than 1,000 plantlets and a large number of somatic embryoids at various developmental stages were obtained per flask.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00269895
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Electroporation-mediated infection of tobacco leaf protoplasts with tobacco mosaic virus RNA and cucumber mosaic virus RNA (1986)
    Springer
    Plant cell reports 5 (1986), S. 57-60 
    Details
    ISSN: 1432-203X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Conditions were established for the introduction of both tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) RNAs into tobacco mesophyll protoplasts by electroporation. The proportion of infected protoplasts was quantified by staining with viral coat protein-specific antibodies conjugated to fluorescein isothiocyanate. Approximately 30–40% of the protoplasts survived electroporation. Under optimal conditions, up to 75% of these were infected with TMV-RNA. Successful infection was demonstrated in 19 out of 20 experiments. Optimal infection was achieved with several direct current pulses of 90 μsec at a field strength of 5 to 10 kV/cm. Changing the position of the protoplasts within the chamber between electric pulses was essential for achievement of high rates of infection. Optimal viral RNA concentration was about 10 μg/ml in a solution of 0.5 M mannitol without buffer salts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00269719
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Expression of genes from the marine bacteriumAlteromonas haloplanktis 214 inEscherichia coli K-12 (1985)
    Springer
    Archives of microbiology 142 (1985), S. 248-252 
    Details
    ISSN: 1432-072X
    Keywords: Alteromonas haloplanktis ; Marine bacteria ; Escherichia coli ; Gene bank ; Gene expression ; Plasmids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract DNA from the marine bacteriumAlteromonas haloplanktis 214 was partially digested withSau 3A and inserted into theBam HI site of the cloning vector pBR322. The ligation mixture was used to transformEscherichia coli HB101. The gene bank plasmid preparation obtained was used to transformEscherichia coli K-12 strain EO2717, an organism auxotrophic for histidine, arginine, adenine, uracil and thiamin. Prototrophic transformants for each of the five metabolites were isolated using appropriate minimal media for selection. Plasmids isolated from each of the transformants were shown by hybridization to containA. haloplanktis DNA and to be capable of complementing the appropriate mutation inE. coli EO2717. Restriction maps showed that each of the plasmids was different.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00693398
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Visualization of bioluminescence as a marker of gene expression in rhizobium-infected soybean root nodules (1988)
    Springer
    Plant molecular biology 10 (1988), S. 387-399 
    Details
    ISSN: 1573-5028
    Keywords: bacterial luciferase ; bioluminescence ; Bradyrhizobium japonicum ; nitrogen fixation ; root nodules ; video microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The linked structural genes lux A and lux B, encoding bacterial luciferase of a marine bacterium Vibrio harveyi, were fused with the nitrogenase nifD promoter from Bradyrhizobium japonicum and with the P1 promoter of pBR322. Both fusions were integrated into the B. japonicum chromosome by site-specific recombination. Soybean roots infected with the two types of rhizobium transconjugants formed nitrogen-fixing nodules that produced bright blue-green light. Cells containing the P1 promoter/lux AB fusion resulted in continuously expressed bioluminescence in both free-living rhizobium and in nodule bacteriods. However, when under control of the nifD promoter, luciferase activity was found only in introgen-fixing nodules. Light emission from bacteroids allowed us to visualize and to photograph nodules expressing this marker gene fusion in vivo at various levels of resolution, including within single, living plant cells. Localization of host cells containing nitrogen-fixing bacteroids within nodule tissue was accomplished using low-light video microscopy aided by realtime image processing techniques developed specifically to enhance extreme low-level luminescent images.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00014945
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Molecular characterization of a stably transformed Bombyx mori cell line: identification of alternative transcriptional initiation sites of the A3 cytoplasmic actin gene (1998)
    Springer
    Molecular genetics and genomics 260 (1998), S. 1-8 
    Details
    ISSN: 1617-4623
    Keywords: Key words Silkworm ; Puromycin N-acetyl transferase ; Stably transformed cell line ; A3 cytoplasmic actin ; 5′ RACE
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have isolated a stably transformed Bombyx mori cell line containing a novel selectable marker gene, puromycin N-acetyl transferase, under control of transcriptional regulatory signals from the A3 cytoplasmic actin gene. By using this cell line we have identified alternative transcriptional initiation sites for the A3 actin gene. One of these start sites is located ∼35 bp upstream from the previously determined transcription initiation site. The two mRNA start sites are utilized with a similar efficiencies in the BmN cell line. In addition, we detected transcripts that initiated in the first intron of the A3 actin gene. These transcripts may be synthesised under control of an alternative promoter. The stably transformed B. mori cell line used in this study was also extensively characterized. Integration of the plasmid molecules into the host genome was demonstrated by Southern and in situ hybridization analyses. Establishment and characterization of stably transformed insect cell lines, like the one described here, represents an important step in the development of non-lytic insect expression systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004380050864
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    DNA sequences homologous to the T DNA region of Agrobacterium tumefaciens are present in diverse Rhizobium species (1982)
    Springer
    Molecular genetics and genomics 188 (1982), S. 361-369 
    Details
    ISSN: 1617-4623
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary DNA sequences homologous to the T DNA region of the octopine-type Ti plasmid from Agrobacterium tumefaciens are present in different Rhizobium species. Plasmid DNA from each of two R. leguminosarum, two R. meliloti, and four slow-growing Rhizobium strains examined contain restriction endonuclease fragments that hybridize with the T DNA region, or with DNA sequences at or near the adjacent Ti plasmid transfer (ra) region. Four different BamHI fragments that contain homology to the T DNA region were cloned from R. leguminosarum 300 plasmid DNA. Cloned fragments of 5.9 kb and 10.3 kb hybridize to each other and are homologous to sequences which map at the right boundary region (EcoRI fragment 24) of the “core” T DNA. Ti plasmid sequences homologous to those present in cloned fragments of 10.9 kb and 2.0 kb map in adjacent fragments near the tra genes, approximately 10 kb to the right of the “core” T DNA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00330035
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Evidence for a megareplicon covering megabases of centromeric chromosome segments (1996)
    Springer
    Chromosome research 4 (1996), S. 240-247 
    Details
    ISSN: 1573-6849
    Keywords: amplification ; centromere ; heterochromatin ; megareplicon ; replication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have analysed the replication of the heterochromatic megachromosome that was formedde novo by a large-scale amplification process initiated in the centromeric region of mouse chromosome 7. The megachromosome is organized into amplicons ∼30 Mb in size, and each amplicon consists of two large inverted repeats delimited by a primary replication initiation site. Our results suggest that these segments represent a higher order replication unit (megareplicon) of the centromeric region of mouse chromosomes. Analysis of the replication of the megareplicons indicates that the pericentric heterochromatin and the centromere of mouse chromosomes begin to replicate early, and that their replication continues through approximately three-quarters of the S-phase. We suggest that a replication-directed mechanism may account for the initiation of large-scale amplification in the centromeric regions of mouse chromosomes, and may also explain the formation of new, stable chromosome segments and chromosomes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02254965
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Mer22-related sequence elements form pericentric repetitive DNA families in primates (2000)
    Springer
    Molecular genetics and genomics 262 (2000), S. 931-939 
    Details
    ISSN: 1617-4623
    Keywords: Key words Centromere ; Chromosome-specific repetitive DNA elements ; MER22 ; Primates ; Speciation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We describe a novel repetitive DNA element isolated from three primate species belonging to the family Cercopithecidae. The unusually long 2.6-kb repeat unit of this DNA element is present in high copy number in the pericentromeric region of one pair of chromosomes in both baboon and macaque, forming chromosome-specific satellite-like DNA families. Besides these two very closely related species, the novel DNA element was also detected in the more distantly related African green monkey. However, the copy number of the repeat unit in this species is significantly lower than in macaque and baboon. Sequence analysis revealed that the repeat units of the new repetitive element show similarity to the human MER22 repeat and the Y chromosome-specific TTY2 element, which also exhibits retroelement-like features. Database searches indicate that tandemly arranged MER22-related DNA sequences can also be found in human, raising the possibility that these DNA elements may correspond to a novel primate-specific repetitive DNA group. Recent studies indicate that chromosome-specific pericentric repetitive elements, besides their potential involvement in centromere function, also facilitate homolog recognition during meiosis. In addition, rapid expansion of retroelements in the pericentric regions of chromosomes during interspecific hybridization has been described. In light of these data, we hypothesize that the novel repetitive element described here might have been involved in the speciation of the family Cercopithecidae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00008661
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    An alternative intronic promoter of the Bombyx A3 cytoplasmic actin gene exhibits a high level of transcriptional activity in mammalian cells (1999)
    Springer
    Molecular genetics and genomics 261 (1999), S. 337-345 
    Details
    ISSN: 1617-4623
    Keywords: Key words A3 cytoplasmic actin ; Silkworm ; Intron ; Alternative promoter ; CArG element
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Previous observations have indicated that the Bombyx mori gene for A3 cytoplasmic actin and vertebrate actin genes might make use of similar mechanisms for regulation of gene expression. To examine the suggested similarities, we have analyzed the expression of a LacZ reporter plasmid construct containing the 5′ and 3′ regulatory regions and the first intron of the A3 actin gene in a variety of vertebrate cell lines. We found that this silkworm expression cassette could drive expression of foreign genes in both mammalian and avian cell lines. Detailed analysis, however, indicated that neither the CArG box nor any of the promoter elements previously identified in the A3 actin gene were required for expression in mammalian cells. On the other hand, the first intron contained an efficient promoter, exhibiting in mouse cells a transcriptional activity comparable to that of the SV40 early promoter. The first intron of the A3 gene was also found to contain enhancer-like DNA elements that could stimulate the heterologous SV40 early promoter in mammalian cells. Promoter activity of the first intron of the A3 actin gene has not been observed previously. Recently however, we described a rare A3 actin mRNA isoform in B. mori cells, which initiates within the first intron. We suggest that the identified intronic promoter may be active not only in vertebrate cells but also in silkworm, and that it regulates the synthesis of the alternative A3 actin mRNA isoform. The characteristics of the 5′ regulatory region of the A3 gene described here can also be exploited in the construction of bi-functional insect-mammalian expression vectors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004380050974
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    De novo chromosome formations by large-scale amplification of the centromeric region of mouse chromosomes (1996)
    Springer
    Chromosome research 4 (1996), S. 226-239 
    Details
    ISSN: 1573-6849
    Keywords: amplification ; centromere ; chromosome formation ; heterochromatin ; satellite DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chromosomes formedde novo which originated from the centromeric region of mouse chromosome 7, have been analysed. These new chromosomes were formed by apparently similar large-scale amplification processes, and are organized into amplicons of ∼30 Mb. Centromeric satellite DNA was found to be the constant component of all amplicons. Satellite DNA sequences either bordered the large euchromatic amplicons (E-type amplification), or made up the bulk of the constitutive heterochromatic amplicons (H-type amplification). Detailed analysis of a heterochromatic megachromosome formedde novo by an H-type amplification revealed that it is composed of a tandem array of 10–12 large (∼30 Mb) amplicons each marked with integrated ‘foreign’ DNA sequences at both ends. Each amplicon is a giant palindrome, consisting of two inverted doublets of ∼7.5-Mb blocks of satellite DNA. Our results indicate that the building units of the pericentric heterochromatin of mouse chromosomes are ∼7.5-Mb blocks of satellite DNA flanked by nonsatellite sequences. We suggest that the formationde novo of various chromosome segments and chromosomes seen in different cell lines may be the result of large-scale E- and H-type amplification initiated in the pericentric region of chromosomes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02254964
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...