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41.
Ingo Marenholz Armin Volz Andreas Ziegler Angela Davies Ioannis Ragoussis Bernhard P. Korge Dietmar Mischke 《Genomics》1996,37(3):295
The epidermal differentiation complex (EDC) unites a remarkable number of structurally, functionally, and evolutionarily related genes that play an important role in terminal differentiation of the human epidermis. It is localized within 2.05 Mb of region q21 on human chromosome 1. We have identified and characterized 24 yeast artificial chromosome (YAC) clones by mapping individual EDC genes, sequence-tagged site (STS) markers (D1S305, D1S442, D1S498, D1S1664), and 10 new region-specific probes (D1S3619–D1S3628). Here we present a contig that covers about 6 Mb of 1q21 including the entire EDC. Fluorescencein situhybridization on metaphase chromosomes with two YACs flanking the EDC determined its chromosomal orientation and established, in conjunction with physical mapping results, the following order of genes and STSs: 1cen–D1S442–D1S498–S100A10–THH–FLG–D1S1664–IVL–SPRR3–SPRR1–SPRR2–LOR–S100A9–S100A8–S100A7–S100A6–S100A5–S100A4–S100A3–S100A2–S100A1–D1S305–1qtel. These integrated physical, cytogenetic, and genetic mapping data will be useful for linkage analyses of diseases associated with region 1q21 and for the identification of novel genes and regulatory elements in the EDC. 相似文献
42.
43.
Bernhard Kraus 《Experimental & applied acarology》1994,18(7):435-443
Reproducing Varroa jacobsoni obtained from brood cells of Apis mellifera L. with 13–16 day old bees (pupae) and Varroa mites kept on adult bees for at least 8 days were simultaneously tested for their choice in three host types. Comparisons were made of attractiveness of Varroa jacobsoni to nurse bees, pollen foragers as to larvae from nearly capped brood cells. Host choices were observed in Petri dishes and in an Y-shaped olfactometer. Varroa jacobsoni obtained from capped brood cells showed a stronger preference for nurse bees in Petri dish simultaneous choice tests with pollen foragers or larvae than did mites which were previously kept on adult bees. In olfactometer simultaneous choice tests, the two mite test groups showed no clear difference in preferences for bees of different ages. The preference of Varroa jacobsoni for bees of different ages is therefore not only influenced by host factors but also by intrinsic factors in female mites that depend on the mite's reproductive stage. 相似文献
44.
45.
Frank Bernhard David L. Coplin Klaus Geider 《Molecular & general genetics : MGG》1993,239(1-2):158-168
A large ams gene cluster required for production of the acidic extracellular polysaccharide (EPS) amylovoran by the fire blight pathogen Erwinia amylovora was cloned. Tn5 mutagenesis and gene replacement were used to construct chromosomal ams mutants. Five complementation groups, essential for amylovoran synthesis and virulence in E. amylovora, were identified and designated amsA-E. The ams gene cluster is about 7 kb in size and functionally equivalent to the cps gene cluster involved in EPS synthesis by the related pathogen Erwinia stewartii. Mucoidy and virulence were restored to E. stewartii mutants in four cps complementation groups by the cloned E. amylovora ams genes. Conversely, the E. stewartii cps gene cluster was able to complement mutations in E. amylovora ams genes. Correspondence was found between the amsA-E complementation groups and the cpsB-D region, but the arrangement of the genes appears to be different. EPS production and virulence were also restored to E. amylovora amsE and E. stewartii cpsD mutants by clones containing the Rhizobium meliloti exoA gene. 相似文献
46.
Sieghart Sopper Susanne Hemm Jürgen Meixensberger Cheik Coulibaly Christiane Stahl-Hennig Gerhard Hunsmann Bernhard Fleckenstein Volker ter Meulen Rüdiger Drries 《Journal of medical primatology》1993,22(2-3):138-146
Paired sera and CSF samples were collected from SIVmac-infected macaques. Animals infected with SIVmac251 maintained low gag and high env-specific antibody levels in plasma. Increasing env-specific antibody titers in CSF were associated in one animal with strong intrathecal synthesis. SIVmac239-infected monkeys revealed high antibody titers of gag and env-specificity, in one animal accompanied by weak intrathecal synthesis of virus-specific antibodies. In all animals, the CD4/CD8 ratio in CSF decreased faster compared to blood. 相似文献
47.
Bernd Johannsen Bernhard Noll Peter Leibnitz Günter Reck Steffi Noll Hartmut Spies 《Inorganica chimica acta》1993,210(2)
The reaction of mercaptoacetyl diglycine (MAG2) with technetium(V) gluconate in aqueous solution produced [TcO(MAG2)]−. A single X-ray structure determination was carried out for the tetraphenylarsonium salt. The dark brown crystals are monoclinic, space group P2(1)/n, with a=12.478(5), b=14.922(5), c=17.183(9) Å and Z=4. The [TcO(MAG2)]− ion has a square pyramidal geometry with the technetium atom displaced by 0.756 Å towards the oxo ligand from the plane formed by the equatorial S,N,N,O atoms. The rhenium complex AsPh4[ReO(MAG2)] was prepared analogously starting from Re(V) gluconate and characterized. 相似文献
48.
The preparation and X-ray structure of [Ag(9-EtGH-N7)2]NO3·H2O(9-EtGH=neutral 9-ethylguanine) is reported. The compound crystallizes in the triclinic system, space group P
with a=7.063(6), b=7.153(3), c=11.306(10) Å, α=83.36(6), β=76.66(7), γ=81.44(6)°. The cation is centrosymmetric with Ag(I) coordinated via two N7 positions and Ag---N7 bond lengths of 2.11(1) Å. Applying 109Ag NMR spectroscopy, complex formation constants for both the 1:1 complex (log β1=0.6) and the title compound (log β2=1.6) in Me2SO have been determined. 相似文献
49.
Glutamate Dehydrogenase Is Not Essential for Glutamate Formation by Corynebacterium glutamicum 下载免费PDF全文
Elke R. Brmann-El Kholy Bernhard J. Eikmanns Marcella Gutmann Hermann Sahm 《Applied microbiology》1993,59(7):2329-2331
Two Corynebacterium glutamicum strains, one being glutamate dehydrogenase (GDH) negative and the other possessing 11-fold-higher specific GDH activity than the parental wild type, were constructed and used to analyze the role of GDH in C. glutamicum. The results indicate (i) that GDH is dispensable for glutamate synthesis required for growth and (ii) that although a high level of GDH increases the intracellular glutamate pool, the level of GDH has no influence on glutamate secretion. 相似文献
50.
Biochemical studies on anaerobic phenylme-thylether cleavage by homoacetogenic bacteria have been hampered so far by the complexity of the reaction chain involving methyl transfer to acetyl-CoA synthase and subsequent methyl group carbonylation to acetyl-CoA. Strain TMBS 4 differs from other demethylating homoacetogenic bacteria in using sulfide as a methyl acceptor, thereby forming methanethiol and dimethylsulfide. Growing and resting cells of strain TMBS 4 used alternatitively CO2 as a precursor of the methyl acceptor CO for homoacetogenic acetate formation. Demethylation was inhibited by propyl iodide and reactivated by light, indicating involvement of a corrinoid-dependent methyltransferase. Strain TMBS 4 contained ca. 750 nmol g dry mass-1 of a corrinoid tentatively identified as 5-hydroxybenzimidazolyl cobamide. A photometric assay for measuring the demethylation activity in cell extracts was developed based on the formation of a yellow complex of Ti3+ with 5-hydroxyvanillate produced from syringate by demethylation. In cell extracts, the methyltransfer reaction from methoxylated aromatic compounds to sulfide or methanethiol depended on reductive activation by Ti3+. ATP and Mg2+ together greatly stimulated this reductive activation without being necessary for the demethylation reaction itself. The specific activity of the transmethylating enzyme system increased proportionally with protein concentration up to 3 mg ml-1 reaching a constant level of 20 nmol min-1 mg-1 at protein concentrations 10 mg ml-1. The specific rate of activation increased in a non-linear manner with protein concentration. Strain TMBS 4 degraded gallate, the product of sequential demethylations, to 3 acetate through the phloroglucinol pathway as found earlier with Pelobacter acidigallici.Abbreviations BV
benzyl viologen
- CTAB
cetyltrimethylammonium bromide
- H4folate
tetrahydrofolate
- MOPS
3-[N-morpholino]propanesulfonic acid
- MV
methyl viologen
- NTA
nitrilotriacetate
- td
doubling time
- TMB
3,4,5-trimethoxybenzoate 相似文献