A 460-kb DNA Sequence of the Escherichia coli K-12 Genome Corresponding to the 40.1-50.0 min Region on the Linkage Map

The 465,813 base pair sequence corresponding to the 40.1–50.0min region on the genetic map of Escherichia coli K-12 (W3110)was determined. Analysis of the sequence revealed that thisregion contained at least 466 potential open reading frames,of which 187 (40%) were previously reported, 105 (23%) werehomologous to other known genes, 103 (22%) were identical orsimilar to hypothetical genes registered in databases, and theremaining 71 (15%) did not show a significant similarity toany other gene. At the 45.2–46.0 min region, we founda very large cluster of about 30 genes, whose functions areinvolved in the biosynthesis of polysaccharides as the componentsof outer membranes. In addition, we identified anew asn-tRNAgene, designated asnW, between the asnT and asnU genes and anew lysogenic phage attachment site as the cis-element.     

Immunochemical Characterization of Plaque Mutants of Simian Virus 40

Analysis of large and small plaque mutants of simian virus 40 using antisera prepared against each has revealed quantitative and possibly qualitative antigenic differences for each plaque type. A sensitive micro radioisotope precipitation test permitted evaluation of immunochemical similarities and differences of capsid antigens by inhibition of precipitation.     

Two guaiane-type sesquiterpene lactones and their related sesquiterpene lactones from Porella japonica

Two new guaiane-type sesquiterpene dilactones, porelladiolide and 3α,4α-epoxyporelladiolide and a new germacranolide, 3β-hydroxycostunolide, together with the previously known germacranolides, guaianolides, pinguisane-type sesquiterpenes, and a sacculatane-type diterpene dialdehyde have been isolated from the liverwort, Porella japonica and their structures have been established by the spectral evidence and some chemical transformations. Porelladiolide, 3α,4α-epoxyporelladiolide and the sesquiterpene with α-methylene γ-lactone group showed inhibitory activity toward the germination and growth of roots of rice in the husk.     

Localization of protein kinase C in normal and galactosemic bovine lens epithelial cells in culture

 The localization of the two major isoforms of protein kinase C (PKC), PKCα and PKCγ, present in normal and galactosemic bovine lens epithelial cells in culture, was determined using PKC isoform-specific antisera and visualized with FITC-conjugated secondary antisera. The results indicated that the localization of PKC changed upon exposure to 40 mM galactose after 1day. The subcellular distribution of control cells was cytoplasmic and perinuclear for PKCα, while, in 40 mM galactose-treated cells, PKCα was also localized to nuclei. In contrast, upon exposure to 40 mM galactose the PKCγ of the lens epithelial cells was observed in nucleoli. These results suggest that the subcellular distribution of the PKC isoforms in bovine lens epithelial cells differs and is altered upon exposure to 40 mM galactose. Accepted: 7 January 1998     

The Dictyostelium developmental cDNA project: generation and analysis of expressed sequence tags from the first-finger stage of development.

In an effort to identify and characterize genes expressed during multicellular development ill Dictyostelium, we have undertaken a cDNA sequencing project. Using size-fractionated subsets of cDNA from the first finger stage, two sets of gridded libraries were constructed for cDNA sequencing. One, library S, consisting of 9984 clones, carries relatively short inserts, and the other, library L, which consists of 8448 clones, has longer inserts. We sequenced all the selected clones in library S from their 3'-ends, and this generated 3093 non-redundant, expressed sequence tags (ESTs). Among them, 246 ESTs hit known Dictyostelium genes and 910 showed significant similarity to genes of Dictyostelium and other organisms. For library L, 1132 clones were randomly sequenced and 471 non-redundant ESTs were obtained. In combination, the ESTs from the two libraries represent approximately 40% of genes expressed in late development, assuming that the non-redundant ESTs correspond to independent genes. They will provide a useful resource for investigating the genetic networks that regulate multicellular development of this organism.