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4753880 Method of selection for spiramycin resistance in streptomyces
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PATENT ABSTRACTS 4753874
4753879
RAPID MUTATION TESTING SYSTEM FOR HUMAN CELLS
MODIFIED TISSUE PLASMINOGEN ACTIVATORS
Michele Calos assigned to Board of Trustees of the Leland Stanford Junior University
Joseph Rosa, Margaret D Rosa assigned to Biogen N V
Mutagenic capability is determined by employing a shuttle vector having prokaryotic and eukaryotic origins, a prokaryotic marker an a gene capable of screeningor selection in a prokaryote. The method involves introducing the vector into mammalian cells, exposing the cells to the candidate to be tested for mutagenicity for a time sufficient to allow lesions to occur, rescuing the vector by transforming into a prokaryotic host and screening for mutations of the gene.
Modified human tissue plasminogen activators, the DNA sequences coding on expression for them and methods of making them in hosts transformed with those DNA sequences. The single chain form of these modified human tPAs, t-PA (Lys 277 right arrowX), has a longer half life than the single chain form of native, or recombinant, t-PA, yet, in the two chain form these modified t-PAs have substantially the same affinity for fibrin and substantially the same activity as the two chain form of native, or recombinant, t-PA.
4753876 MARKER GENES IN P S E U D O M O N A D BACTERIA
Bruce Hemming, David Drahos assigned to Monsanto Company This invention discloses the use of marker genes which do not involve antibiotics for environmental tracking of microorganisms. Such marker genes include chromogenic marker genes, and marker genes that allow a cell to proliferate on media containing a sole nutrient source which cannot be utilized by untransformed cells. Genetic transformation using such marker genes is used to create cells with two or more phenotypic traits that do not coexist in natural, untransformed cells. As one example, pseudonomad cells have been transformed with beta-galactosidase and lactose permease genes, to create cells which are (1) fluorescent, (2) able to hydrolyze X-gal or ONPG, and (3) capable of proliferation on lactose as a sole carbon source. Such cells are useful as soil inoculants, and their descendants can be tracked by using these characteristics. The marker genes may be placed under the control of inducible promoters.
4753880 METHOD OF SELECTION FOR SPIRAMYCIN RESISTANCE IN STREPTOMYCES
Nancy A Schaus, Patricia J Solenberg assigned to Eli Lilly and Company A novel method, of selecting Streptomyces recombinant DNA-containing host cells and vectors useful in the method are described. The vectors confer spiramycin resistance to sensitive Streptomyces host cells and thus provide a convenient method of selecting Streptomyces transformants. The novel spiramycin resistanceconferring gene described can be isolated on an 3.8 kb BclI restriction fragment from plasmid pNASI05. Plasmid pNASI05 can be isolated from Streptomyces griseofuscus C581/pNAS 105 (NRRL 15919).
PATENT ABSTRACTS 4753874
4753879
RAPID MUTATION TESTING SYSTEM FOR HUMAN CELLS
MODIFIED TISSUE PLASMINOGEN ACTIVATORS
Michele Calos assigned to Board of Trustees of the Leland Stanford Junior University
Joseph Rosa, Margaret D Rosa assigned to Biogen N V
Mutagenic capability is determined by employing a shuttle vector having prokaryotic and eukaryotic origins, a prokaryotic marker an a gene capable of screeningor selection in a prokaryote. The method involves introducing the vector into mammalian cells, exposing the cells to the candidate to be tested for mutagenicity for a time sufficient to allow lesions to occur, rescuing the vector by transforming into a prokaryotic host and screening for mutations of the gene.
Modified human tissue plasminogen activators, the DNA sequences coding on expression for them and methods of making them in hosts transformed with those DNA sequences. The single chain form of these modified human tPAs, t-PA (Lys 277 right arrowX), has a longer half life than the single chain form of native, or recombinant, t-PA, yet, in the two chain form these modified t-PAs have substantially the same affinity for fibrin and substantially the same activity as the two chain form of native, or recombinant, t-PA.
4753876 MARKER GENES IN P S E U D O M O N A D BACTERIA
Bruce Hemming, David Drahos assigned to Monsanto Company This invention discloses the use of marker genes which do not involve antibiotics for environmental tracking of microorganisms. Such marker genes include chromogenic marker genes, and marker genes that allow a cell to proliferate on media containing a sole nutrient source which cannot be utilized by untransformed cells. Genetic transformation using such marker genes is used to create cells with two or more phenotypic traits that do not coexist in natural, untransformed cells. As one example, pseudonomad cells have been transformed with beta-galactosidase and lactose permease genes, to create cells which are (1) fluorescent, (2) able to hydrolyze X-gal or ONPG, and (3) capable of proliferation on lactose as a sole carbon source. Such cells are useful as soil inoculants, and their descendants can be tracked by using these characteristics. The marker genes may be placed under the control of inducible promoters.
4753880 METHOD OF SELECTION FOR SPIRAMYCIN RESISTANCE IN STREPTOMYCES
Nancy A Schaus, Patricia J Solenberg assigned to Eli Lilly and Company A novel method, of selecting Streptomyces recombinant DNA-containing host cells and vectors useful in the method are described. The vectors confer spiramycin resistance to sensitive Streptomyces host cells and thus provide a convenient method of selecting Streptomyces transformants. The novel spiramycin resistanceconferring gene described can be isolated on an 3.8 kb BclI restriction fragment from plasmid pNASI05. Plasmid pNASI05 can be isolated from Streptomyces griseofuscus C581/pNAS 105 (NRRL 15919).