Regulation of neural progenitor cell state by ephrin-B

Maintaining a balance between self-renewal and differentiation in neural progenitor cells during development is important to ensure that correct numbers of neural cells are generated. We report that the ephrin-B–PDZ-RGS3 signaling pathway functions to regulate this balance in the developing mammalian cerebral cortex. During cortical neurogenesis, expression of ephrin-B1 and PDZ-RGS3 is specifically seen in progenitor cells and is turned off at the onset of neuronal differentiation. Persistent expression of ephrin-B1 and PDZ-RGS3 prevents differentiation of neural progenitor cells. Blocking RGS-mediated ephrin-B1 signaling in progenitor cells through RNA interference or expression of dominant-negative mutants results in differentiation. Genetic knockout of ephrin-B1 causes early cell cycle exit and leads to a concomitant loss of neural progenitor cells. Our results indicate that ephrin-B function is critical for the maintenance of the neural progenitor cell state and that this role of ephrin-B is mediated by PDZ-RGS3, likely via interacting with the noncanonical G protein signaling pathway, which is essential in neural progenitor asymmetrical cell division

Identification of novel and conserved microRNAs involved in fruit development and ripening in Fragaria vesca

MicroRNAs (miRNAs) are class of noncoding RNAs that regulate gene expression at the post-transcriptional level, either by endonucleolytic cleavage or by translational inhibition. Strawberry is a popular worldwide fresh fruit and is believed to benefit human health. However, the function of miRNAs during this fruit development and ripening remains unknown and miRNAs for specific for these processes are expected to be discovered. In the study, we identified 218 conserved miRNAs and 87 novel miRNAs in Fragaria vesca. Expression profiling of miRNAs during fruit development and ripening was performed, and the expression of targets of the miRNAs was validated by qRT-PCR (quantitative reverse transcription polymerase chain reaction). This study provided data for further research on molecular mechanisms involved in fruit development and ripening

Advancing College Food Security: Priority Research Gaps

Despite over a decade of both quantitative and qualitative studies, food insecurity among United States college/university students remains a pervasive problem within higher education. The purpose of this perspective piece was to highlight research gaps in the area of college food insecurity and provide rationale for the research community to focus on these gaps going forward. A group of food insecurity researchers from a variety of higher education institutions across the United States identified five thematic areas of research gaps: screening and estimates of food insecurity; longitudinal changes in food insecurity; impact of food insecurity on broader health and academic outcomes; evaluation of impact, sustainability, and cost effectiveness of existing programs and initiatives; and state and federal policies and programs. Within these thematic areas, 19 specific research gaps were identified that have limited or no peer-reviewed, published research. These research gaps result in a limited understanding of the magnitude, severity, and persistence of college food insecurity, the negative short- and long-term impacts of food insecurity on health, academic performance, and overall college experience, and effective solutions and policies to prevent or meaningfully address food insecurity among college students. Research in these identified priority areas may help accelerate action and interdisciplinary collaboration to alleviate food insecurity among college students and play a critical role in informing the development or refinement of programs and services that better support college student food security needs

Advancing college food security: priority research gaps

Despite over a decade of both quantitative and qualitative studies, food insecurity among US college/university students remains a pervasive problem within higher education. The purpose of this perspective piece was to highlight research gaps in the area of college food insecurity and provide rationale for the research community to focus on these gaps going forward. A group of food insecurity researchers from a variety of higher education institutions across the United States identified five thematic areas of research gaps: screening and estimates of food insecurity; longitudinal changes in food insecurity; impact of food insecurity on broader health and academic outcomes; evaluation of impact, sustainability and cost effectiveness of existing programmes and initiatives; and state and federal policies and programmes. Within these thematic areas, nineteen specific research gaps were identified that have limited or no peer-reviewed, published research. These research gaps result in a limited understanding of the magnitude, severity and persistence of college food insecurity, the negative short- and long-term impacts of food insecurity on health, academic performance and overall college experience, and effective solutions and policies to prevent or meaningfully address food insecurity among college students. Research in these identified priority areas may help accelerate action and interdisciplinary collaboration to alleviate food insecurity among college students and play a critical role in informing the development or refinement of programmes and services that better support college student food security needs

NOA1 Functions in a Temperature-Dependent Manner to Regulate Chlorophyll Biosynthesis and Rubisco Formation in Rice

NITRIC OXIDE-ASSOCIATED1 (NOA1) encodes a circularly permuted GTPase (cGTPase) known to be essential for ribosome assembly in plants. While the reduced chlorophyll and Rubisco phenotypes were formerly noticed in both NOA1-supressed rice and Arabidopsis, a detailed insight is still necessary. In this study, by using RNAi transgenic rice, we further demonstrate that NOA1 functions in a temperature-dependent manner to regulate chlorophyll and Rubisco levels. When plants were grown at 30°C, the chlorophyll and Rubisco levels in OsNOA1-silenced plants were only slightly lower than those in WT. However, at 22°C, the silenced plants accumulated far less chlorophyll and Rubisco than WT. It was further revealed that the regulation of chlorophyll and Rubisco occurs at the anabolic level. Etiolated WT seedlings restored chlorophyll and Rubisco accumulations readily once returned to light, at either 30°C or 15°C. Etiolated OsNOA1-silenced plants accumulated chlorophyll and Rubisco to normal levels only at 30°C, and lost this ability at low temperature. On the other hand, de-etiolated OsNOA1-silenced seedlings maintained similar levels of chlorophyll and Rubisco as WT, even after being shifted to 15°C for various times. Further expression analyses identified several candidate genes, including OsPorA (NADPH: protochlorophyllide oxidoreductase A), OsrbcL (Rubisco large subunit), OsRALyase (Ribosomal RNA apurinic site specific lyase) and OsPuf4 (RNA-binding protein of the Puf family), which may be involved in OsNOA1-regulated chlorophyll biosynthesis and Rubisco formation. Overall, our results suggest OsNOA1 functions in a temperature-dependent manner to regulate chlorophyll biosynthesis, Rubisco formation and plastid development in rice

Allosteric Regulation of Fibronectin/α5β1 Interaction by Fibronectin-Binding MSCRAMMs

Citation: Liang, X. W., Garcia, B. L., Visai, L., Prabhakaran, S., Meenan, N. A. G., Potts, J. R., . . . Hook, M. (2016). Allosteric Regulation of Fibronectin/alpha(5)beta(1) Interaction by Fibronectin-Binding MSCRAMMs. Plos One, 11(7), 17. doi:10.1371/journal.pone.0159118Adherence ofmicrobes to host tissues is a hallmark of infectious disease and is often mediated by a class of adhesins termed MSCRAMMs (Microbial Surface Components Recognizing Adhesive Matrix Molecules). Numerous pathogens express MSCRAMMs that specifically bind the heterodimeric human glycoprotein fibronectin (Fn). In addition to roles in adhesion, Fn-binding MSCRAMMs exploit physiological Fn functions. For example, several pathogens can invade host cells by a mechanism whereby MSCRAMM-bound Fn bridges interaction with alpha(5)beta(1) integrin. Here, we investigate two Fn-binding MSCRAMMs, FnBPA (Staphylococcus aureus) and BBK32 (Borrelia burgdorferi) to probe structure-activity relationships of MSCRAMM-induced Fn/alpha(5)beta(1) integrin activation. Circular dichroism, fluorescence resonance energy transfer, and dynamic light scattering techniques uncover a conformational rearrangement of Fn involving domains distant from the MSCRAMM binding site. Surface plasmon resonance experiments demonstrate a significant enhancement of Fn/alpha(5)beta(1) integrin affinity in the presence of FnBPA or BBK32. Detailed kinetic analysis of these interactions reveal that this change in affinity can be attributed solely to an increase in the initial Fn/alpha(5)beta(1) on-rate and that this rate-enhancement is dependent on high-affinity Fn-binding by MSCRAMMs. These data implicate MSCRAMM-induced perturbation of specific intramolecular contacts within the Fn heterodimer resulting in activation by exposing previously cryptic alpha(5)beta(1) interaction motifs. By correlating structural changes in Fn to a direct measurement of increased Fn/alpha(5)beta(1) affinity, this work significantly advances our understanding of the structural basis for the modulation of integrin function by Fn-binding MSCRAMMs

All's well that begins Wells: Celebrating 60 years of Animal Behaviour and 36 years of research on anuran social behaviour

The scientific study of frogs and toads as important systems in behavioural ecology traces its roots to an influential review published in this journal 36 years ago (Wells 1977a, ‘The social behaviour of anuran amphibians’, Animal Behaviour, 25, 666–693). In just 28 pages, Wells summarized the state of knowledge on important behaviours associated with anuran breeding and introduced an evolutionary framework ‘for understanding the relationship between social behaviour and ecology’ (page 666) that was largely lacking in earlier treatments of this group. Not only is Wells's review one of the most cited papers ever published in Animal Behaviour, it is also responsible for setting broad research agendas and shaping much of our current thinking on social behaviour in an entire order of vertebrates. As such, it is entirely appropriate that we honour Wells's review and its contributions to the study of animal behaviour in this inaugural essay celebrating 12 papers selected by the community as the most influential papers published in the 60-year history of Animal Behaviour. In our essay, we place Wells's review in historical context at the dawn of behavioural ecology, highlight the field's progress in answering some major research questions outlined in the review, and provide our own prospectus for future research on the social behaviour of anuran amphibians. Highlights ► This essay celebrates Kent Wells's (1977, Animal Behaviour, 25, 666–693) paper, ‘The social behaviour of anuran amphibians’. ► We place the article in historical context and outline its major contributions. ► We discuss progress on anuran social behaviour since its publication in 1977. ► We provide our own prospectus on the future of anuran behavioural ecology