Experimental studies of proton-neutron mixed symmetry states in the mass A ∼ 130 region

Considerable progress has been achieved recently in the experimental investigation of quadrupole-collective isovector excitations in the valence shell, the so called mixed-symmetry states (MSSs), in the mass A ≈ 130 region. This is due to a new experimental technique for study MSSs which is based on the observation of low-multiplicity γ-ray events from inverse kinematics Coulomb excitation with the large 4π spectrometer, such as Gammasphere. The obtained experimental information for the MSSs of stable N 80 isotones indicates that for low-collective vibrational nuclei the underlying single-particle structure can be the most important factor for preserving or fragmenting the MSSs through the mechanism of shell stabilization. The evolution of the MSSs from 134Xe to 138Ce is also used to determine the local strength of the proton-neutron interaction derived for first time from states with symmetric and antisymmetric nature

Development and characterization of polymorphic microsatellite markers in taro (Colocasia esculenta)

Microsatellite-containing sequences were isolated from enriched genomic libraries of taro (Colocasia esculenta (L.) Schott). The sequencing of 269 clones yielded 77 inserts containing repeat motifs. The majority of these (81.7%) were dinucleotide or trinucleotide repeats. The GT/CA repeat motif was the most common, accounting for 42% of all repeat types. From a total of 43 primer pairs designed, 41 produced markers within the expected size range. Sixteen (39%) were polymorphic when screened against a restricted set of taro genotypes from Southeast Asia and Oceania, with an average of 3.2 alleles detected on each locus. These markers represent a useful resource for taro germplasm management, genome mapping, and marker-assisted selection

Isolation and characterization of microsatellites in Sparganium emersum and cross-species amplification in the related species S. erectum

We developed seven novel polymorphic microsatellite loci for the aquatic macrophyte Sparganium emersum (Sparganiaceae). These were characterized on 62 individuals collected from nine different populations. In this set of individuals, seven to 20 alleles per locus were detected and observed heterozygosity ranged between 0.16 and 0.95. Cross-species amplification was tested in the related species Sparganium erectum, and was successful for five of the seven microsatellite loci. [KEYWORDS: dispersal ; gene flow ; microsatellites ; null alleles ; population]

Transcription of DNA-histone complexes by yeast RNA polymerase B.

Transcription of denatured DNA complexed with histones (total, H1 or H2A/H2B/H3/H4) by yeast RNA polymerase B is investigated. Binding of histones to DNA restricts its template activity by decreasing the formation of active, heparin-resistant, RNA polymerase initiation complexes. The elongation of pre-initiated RNA on denatured DNA, complexed with histones, is possible, although resulting in somewhat shorter RNA chains. It is suggested that RNA polymerase B can elongate on a DNA strand covered with histones

Expression and localization of PCSK9 in rat hepatic cells.

Proprotein convertase subtilisin/kexin type 9 (PCSK9), recently cloned in several laboratories, including ours, causes a third form of autosomal dominant hypercholesterolemia. Its mechanism of action remains unclear. We studied the expression and subcellular localization of PCSK9 in fetal and adult rat tissues associated with cholesterol homeostasis using quantitative reverse transcriptase--PCR, Western blot analysis, subcellular fractionation, and confocal immunofluorescent microscopy. PCSK9 mRNA is most abundant in yolk sac and fetal liver, but the highest expression of the protein was found in differentiated hepatoma FAO-1 cell line, which also shows the highest expression of LDLR. In FAO-1 cells PCSK9 expression is downregulated by cholesterol and 25-hydroxycholesterol and upregulated in the absence of sterols following the same pattern of expression as HMG-CoA reductase, synthase, and LDLR. Subcellular fractionation, combined with Western blotting, showed that PCSK9 is localized in the ER and intermediate vesicular compartment of the cell but not in Golgi cisternae. The mature enzyme is secreted from the liver and hepatoma cells. Double labeling with antibodies to PCSK9 and LDLR or clathrin revealed some colocalization of PCSK9 with clathrin-coated vesicles and LDLR. In conclusion, our results show that PCSK9 is processed in the ER, and the mature convertase is secreted in the plasma

Isolation and characterization of highly polymorphic microsatellite markers in Hypochaeris radicata (Asteraceae)

Item does not contain fulltextWe developed five highly polymorphic dinucleotide microsatellite loci for the grassland species Hypochaeris radicata (Asteraceae). Polymorphism of these markers was examined in six populations in the Netherlands. All loci were polymorphic in all populations. The number of alleles per locus varied between 18 and 43. Expected heterozygosity was between 0.86 and 0.91. Cross-species amplification was tested in six Hypochaeris species and was successful for three different loci in four species. These microsatellites are a useful tool in population genetic, dispersal and metapopulation studies or in testing levels of inbreeding

A single amino acid exchange inverts susceptibility of related receptor tyrosine kinases for the ATP-site inhibitor STI-571

The tyrosine kinase inhibitor STI-571 potently blocks BCR-Abl, platelet-derived growth factor (PDGF) a- and b-receptors, and c-Kit kinase activity. However Flt3, a receptor tyrosine kinase closely related to PDGF receptors and c-Kit, is not inhibited by STI-571. Sequence alignments of different kinases and indications from the crystal structure of the STI-571 Abl kinase complex revealed amino acid residues that are probably crucial for this activity profile. It was predicted that Flt3 Phe-691 in the b5 strand may sterically prevent interaction with STI-571. The point mutants Flt3 F691T and PDGFb-receptor T681F were constructed, and kinase assays showed that the Flt3 mutant but not the PDGFb-receptor mutant is inhibited by STI-571. Docking of STI-571 into computer models of the PDGFb-receptor and Flt3 kinase domains and comparison with the crystal structure of the STI-571 Abl kinase complex indicated very similar binding sites among the three nonphosphorylated kinases, suggesting corresponding courses of their Asp-Phe-Gly motifs and activation loops. Accordingly, we obsd. reduced sensitivity of preactivated compared with nonactivated PDGFR-b for the inhibition by STI-571. Courses of the activation loop that collide with STI-571 binding explain its inactivity toward other kinases such as the insulin receptor. The binding site models of PDGFR-b and Flt3 were applied to predict structural approaches for more selective PDGFb-receptor inhibitors