This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5' and 3' boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.

To estimate the minimal gene set required to sustain bacterial life in nutritious conditions, we carried out a systematic inactivation of Bacillus subtilis genes. Among Ϸ4,100 genes of the organism, only 192 were shown to be indispensable by this or previous work. Another 79 genes were predicted to be essential. The vast majority of essential genes were categorized in relatively few domains of cell metabolism, with about half involved in information processing, one-fifth involved in the synthesis of cell envelope and the determination of cell shape and division, and one-tenth related to cell energetics. Only 4% of essential genes encode unknown functions. Most essential genes are present throughout a wide range of Bacteria, and almost 70% can also be found in Archaea and Eucarya. However, essential genes related to cell envelope, shape, division, and respiration tend to be lost from bacteria with small genomes. Unexpectedly, most genes involved in the Embden-Meyerhof-Parnas pathway are essential. Identification of unknown and unexpected essential genes opens research avenues to better understanding of processes that sustain bacterial life.

Efficient organic light-emitting diodes have been developed using emitters containing rare metals, such as platinum and iridium complexes. However, there is an urgent need to develop emitters composed of more abundant materials. Here we show a thermally activated delayed fluorescence material for organic light-emitting diodes, which realizes both approximately 100% photoluminescence quantum yield and approximately 100% up-conversion of the triplet to singlet excited state. The material contains electron-donating diphenylaminocarbazole and electron-accepting triphenyltriazine moieties. The typical trade-off between effective emission and triplet-to-singlet up-conversion is overcome by fine-tuning the highest occupied molecular orbital and lowest unoccupied molecular orbital distributions. The nearly zero singlet–triplet energy gap, smaller than the thermal energy at room temperature, results in an organic light-emitting diode with external quantum efficiency of 29.6%. An external quantum efficiency of 41.5% is obtained when using an out-coupling sheet. The external quantum efficiency is 30.7% even at a high luminance of 3,000 cd m−2.

Triarylboron compounds have attracted much attention, and found wide use as functional materials because of their electron-accepting properties arising from the vacant p orbitals on the boron atoms. In this study, we design and synthesize new donor-acceptor triarylboron emitters that show thermally activated delayed fluorescence. These emitters display sky-blue to green emission and high photoluminescence quantum yields of 87-100 % in host matrices. Organic light-emitting diodes using these emitting molecules as dopants exhibit high external quantum efficiencies of 14.0-22.8 %, which originate from efficient up-conversion from triplet to singlet states and subsequent efficient radiative decay from singlet to ground states.

[10]Cycloparaphenylene ([10]CPP) and its tetraalkoxy derivatives were synthesized on the gram scale in 7 steps starting from 1,4-benzoquinone or 2,5-dialkoxy-1,4-benzoquinone. The key steps involve the highly cis-selective bis-addition of 4-bromo-4'-lithiobiphenyl to the quinones to produce a five-ring unit containing cyclohexa-1,4-diene-3,6-diol moiety, the platinum-mediated dimerization of the five-ring unit, and the HSnCl-mediated reductive aromatization of cyclohexadienediol. The tetraalkoxy substituents increased the solubility of [10]CPP in common organic solvents. The carrier-transport properties of thin films of [10]CPP and its derivatives were measured for the first time and indicated that [10]CPP derivatives could rival phenyl-C-butyric acid methyl ester, which is used widely as an n-type active layer in bulk heterojunction photovoltaics.

SummaryThe concerted interconnection between processes driving DNA synthesis, division septum formation and cell wall synthesis and remodelling in rapidly growing bacteria requires precise co-ordination by signalling mechanisms that are, for the most part,

A new peptidoglycan hydrolase, Bacillus subtilis YojL (cell wall-lytic enzyme associated with cell separation, renamed CwlS), exhibits high amino acid sequence similarity to LytE (CwlF) and LytF (CwlE), which are associated with cell separation. The N-terminal region of CwlS has four tandem repeat regions (LysM repeats) predicted to be a peptidoglycan-binding module. The C-terminal region exhibits high similarity to the cell wall hydrolase domains of LytE and LytF at their C-terminal ends. The C-terminal region of CwlS produced in Escherichia coli could hydrolyze the linkage of D-␥-glutamyl-meso-diaminopimelic acid in the cell wall of B. subtilis, suggesting that CwlS is a D,L-endopeptidase. ␤-Galactosidase fusion experiments and Northern hybridization analysis suggested that the cwlS gene is transcribed during the late vegetative and early stationary phases. A cwlS mutant exhibited a cell shape similar to that of the wild type; however, a lytE lytF cwlS triple mutant exhibited aggregated microfiber formation. Moreover, immunofluorescence microscopy showed that FLAG-tagged CwlS was localized at cell separation sites and cell poles during the late vegetative phase. The localization sites are similar to those of LytF and LytE, indicating that CwlS is involved in cell separation with LytF and LytE. These specific localizations may be dependent on the LysM repeats in their N-terminal domains. The roles of CwlS, LytF, and LytE in cell separation are discussed.

The predicted amino acid sequence of Bacillus subtilis yfjS (renamed pdaA) exhibits high similarity to those of several polysaccharide deacetylases. ␤-Galactosidase fusion experiments and results of Northern hybridization with sporulation sigma mutants indicated that the pdaA gene is transcribed by E G RNA polymerase. pdaA-deficient spores were bright by phase-contrast microscopy, and the spores were induced to germination on the addition of L-alanine. Germination-associated spore darkening, a slow and partial decrease in absorbance, and slightly lower dipicolinic acid release compared with that by the wild-type strain were observed. In particular, the release of hexosamine-containing materials was lacking in the pdaA mutant. Muropeptide analysis indicated that the pdaA-deficient spores completely lacked muramic ␦-lactam. A pdaA-gfp fusion protein constructed in strain 168 and pdaA-deficient strains indicated that the protein is localized in B. subtilis spores. The biosynthetic pathway of muramic ␦-lactam is discussed.Bacillus subtilis produces spores under various nutrient limitations, and this provides a survival mechanism under adverse environmental conditions (25). On the addition of germinants, spores start to germinate and refractility quickly decreases (17). At the same time dipicolinic acid is released, and then cortex fragments containing hexosamine are released from the spores (17). The cortex is one of the most characteristic structures in spores and is degraded by germination-specific cortex lytic enzymes (GSLEs) (3, 17). SleB and CwlJ are candidate GSLEs (10,15,17), and it is believed that these proteins recognize the muramic ␦-lactam structure, which is unique in spore cortex (7,17,24), because Bacillus cereus SleB, which is highly homologous to B. subtilis SleB and CwlJ, degrades normal cortex but not muramic ␦-lactam-deficient cortex (13, 17; S. Makino and R. Moriyama, unpublished results).Previously, two groups suggested that an N-acetylmuramoyl-L-alanine amidase homologue, CwlD, is associated with the biosynthesis of muramic ␦-lactam (4, 18) because a cwlD-deficient mutant completely lacked muramic ␦-lactam (4, 18) and expressed a germination-negative phenotype (21). The cortex of the mutant exhibited higher cross-linkage than the wild-type spores (4, 18). Under the B. subtilis functional analysis project, we analyzed the germination of spores from more than 500 disrupted strains (22). One of the mutations, yfjS, exhibited almost no germination (as measured by recovery of colonies from spores). The amino acid sequence similarity of YfjS with sequences in protein databases suggested it is a polysaccharide deacetylase homologue (BSORF database). In legumes, this enzyme is known as nodulation enzyme B (8), and two homologous gene products in yeast are chitin deacetylases (14).In this paper we describe the germination profiles of the yfjS mutant and the yfjS gene, which is associated with muramic ␦-lactam biosynthesis in the spore cortex. MATERIALS AND METHODSBacterial strains and plasmids. The str...