The embryonic mouse lung is a widely used substitute for human lung development. For example, attempts to differentiate human pluripotent stem cells to lung epithelium rely on passing through progenitor states that have only been described in mouse. The tip epithelium of the branching mouse lung is a multipotent progenitor pool that self-renews and produces differentiating descendants. We hypothesized that the human distal tip epithelium is an analogous progenitor population and tested this by examining morphology, gene expression and in vitro self-renewal and differentiation capacity of human tips. These experiments confirm that human and mouse tips are analogous and identify signalling pathways that are sufficient for long-term self-renewal of human tips as differentiation-competent organoids. Moreover, we identify mouse-human differences, including markers that define progenitor states and signalling requirements for long-term self-renewal. Our organoid system provides a genetically-tractable tool that will allow these human-specific features of lung development to be investigated.DOI: http://dx.doi.org/10.7554/eLife.26575.001

Nanog, a core pluripotency factor in the inner cell mass of blastocysts, is also expressed in unipotent primordial germ cells (PGCs) in mice, where its precise role is yet unclear. We investigated this in an in vitro model, in which naive pluripotent embryonic stem (ES) cells cultured in basic fibroblast growth factor (bFGF) and activin A develop as epiblast-like cells (EpiLCs) and gain competence for a PGC-like fate. Consequently, bone morphogenetic protein 4 (BMP4), or ectopic expression of key germline transcription factors Prdm1, Prdm14 and Tfap2c, directly induce PGC-like cells (PGCLCs) in EpiLCs, but not in ES cells. Here we report an unexpected discovery that Nanog alone can induce PGCLCs in EpiLCs, independently of BMP4. We propose that after the dissolution of the naive ES-cell pluripotency network during establishment of EpiLCs, the epigenome is reset for cell fate determination. Indeed, we found genome-wide changes in NANOG-binding patterns between ES cells and EpiLCs, indicating epigenetic resetting of regulatory elements. Accordingly, we show that NANOG can bind and activate enhancers of Prdm1 and Prdm14 in EpiLCs in vitro; BLIMP1 (encoded by Prdm1) then directly induces Tfap2c. Furthermore, while SOX2 and NANOG promote the pluripotent state in ES cells, they show contrasting roles in EpiLCs, as Sox2 specifically represses PGCLC induction by Nanog. This study demonstrates a broadly applicable mechanistic principle for how cells acquire competence for cell fate determination, resulting in the context-dependent roles of key transcription factors during development.

There remains a flourishing interest in self esteem/self concept both in academic and clinical circles and popular literature. This paper elaborates various notions of the self and discusses the principles underpinning ways of measuring self esteem/self concept with children and adolescents. A review over the last 20 years indicates a raft of scales currently employed. The 14 most frequently cited are considered, with the top six measures and the latest British scale discussed in detail. The paper highlights issues and themes emerging from a comprehensive analysis of these scales, with a conclusion framed around assisting the reader to make an informed choice.

Time is seen as a fundamental but neglected variable in organizational analysis. The paper develops a model of organizational time based upon the notion of a timeframe whereby time is advocated as a socially constructed variable, experienced in the present as represented by a number of variables which form four clusters of time. Explanations of this experience of time in the present derive from the organizational and institutional context. The timeframe of an organization is also seen to affect decision making and learning processes. The timeframe is bounded by knowledge of the past which is used to envision the future. The essential aspect of the past is the extent to which past knowledge can be codified, while the essential aspect of the future is the degree of congru ence over visions of the future. The timeframe model is used to develop scen arios of how knowledge codification and goal congruence can change.

Summary Super-resolution microscopy requires that subcellular structures are labeled with bright and photostable fluorophores, especially for live-cell imaging. Organic fluorophores may help here as they can yield more photons—by orders of magnitude—than fluorescent proteins. To achieve molecular specificity with organic fluorophores in live cells, self-labeling proteins are often used, with HaloTags and SNAP-tags being the most common. However, how these two different tagging systems compare with each other is unclear, especially for stimulated emission depletion (STED) microscopy, which is limited to a small repertoire of fluorophores in living cells. Herein, we compare the two labeling approaches in confocal and STED imaging using various proteins and two model systems. Strikingly, we find that the fluorescent signal can be up to 9-fold higher with HaloTags than with SNAP-tags when using far-red rhodamine derivatives. This result demonstrates that the labeling strategy matters and can greatly influence the duration of super-resolution imaging.

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problems, and signs related to the wetting behaviour; 8269 (73.5%) questionnaires were returned and 8151 contained information on the frequency of bedwetting. RESULTSIn all, 1260 children (15.5%) at 7.5 years wet the bed, but most wet once or less a week, and only 215 (2.6%) met the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) criteria of NE (wetting at least twice a week). A higher prevalence was reported in boys than girls and 266 children (3.3%) had both daytime wetting and bedwetting, with 189 (2.3%) having both daytime soiling and bedwetting. Daytime urgency increased with severity of bedwetting and occurred in 28.9% of children with NE. CONCLUSIONAt 7.5 years old the incidence of bedwetting is high, but only 2.6% of this large populationbased sample wet at a frequency meeting the definition of NE. Although a small percentage of children had both daytime wetting and bedwetting, the evidence suggests that these are discrete problems. Amongst children with NE, indicators of bladder overactivity were present, supporting the view of heterogeneity and the importance of individual assessment in deciding on appropriate treatment.

Children with the severest form of bedwetting are likely to persist with the problem and to have the more complex form (non-monosymptomatic). The results are discussed in relation to the clinical importance of early identification.