The effects of food quantity,light, and temperature on clearance rates in freshwater bivalves (Cyrenidae and Unionidae)

Hydrobiologia - Assessing the environmental variables that influence freshwater bivalve filtration activity is key to better understand the functioning of stream ecosystems. In the present study,...     

Endoplasmic Reticulum Structure and Interconnections with Other Organelles

The endoplasmic reticulum (ER) is a large, continuous membrane-bound organelle comprised of functionally and structurally distinct domains including the nuclear envelope, peripheral tubular ER, peripheral cisternae, and numerous membrane contact sites at the plasma membrane, mitochondria, Golgi, endosomes, and peroxisomes. These domains are required for multiple cellular processes, including synthesis of proteins and lipids, calcium level regulation, and exchange of macromolecules with various organelles at ER-membrane contact sites. The ER maintains its unique overall structure regardless of dynamics or transfer at ER-organelle contacts. In this review, we describe the numerous factors that contribute to the structure of the ER.The endoplasmic reticulum (ER) is a dynamic organelle responsible for many cellular functions, including the synthesis of proteins and lipids, and regulation of intracellular calcium levels. This review focuses on the distinct and complex morphology of the ER. The structure of the ER is complex because of the numerous distinct domains that exist within one continuous membrane bilayer. These domains are shaped by interactions with the cytoskeleton, by proteins that stabilize membrane shape, and by a homotypic fusion machinery that allows the ER membrane to maintain its continuity and identity. The ER also contains domains that contact the plasma membrane (PM) and other organelles including the Golgi, endosomes, mitochondria, lipid droplets, and peroxisomes. ER contact sites with other organelles and the PM are both abundant and dispersed throughout the cytoplasm, suggesting that they too could influence the overall architecture of the ER. As we will discuss here, ER shape and distribution are regulated by many intrinsic and extrinsic forces.     

Autophagy

Autophagy is an evolutionarily conserved cellular process through which long-lived proteins and damaged organelles are recycled to maintain energy homeostasis. These proteins and organelles are sequestered into a double-membrane structure, or autophagosome, which subsequently fuses with a lysosome in order to degrade the cargo. Although originally classified as a type of programmed cell death, autophagy is more widely viewed as a basic cell survival mechanism to combat environmental stressors. Autophagy genes were initially identified in yeast and were found to be necessary to circumvent nutrient stress and starvation. Subsequent elucidation of mammalian gene counterparts has highlighted the importance of this process to normal development. This review provides an overview of autophagy, the types of autophagy, its regulation and its known impact on development gleaned primarily from murine models.     

Nutrigenomics-based personalised nutritional advice: in search of a business model?

Nutritional advice has mainly focused on population-level recommendations. Recent developments in nutrition, communication, and marketing sciences have enabled potential deviations from this dominant business model in the direction of personalisation of nutrition advice. Such personalisation efforts can take on many forms, but these have in common that they can only be effective if they are supported by a viable business model. The present paper takes an inventory of approaches to personalised nutrition currently available in the market place as its starting point to arrive at an identification of their underlying business models. This analysis is presented as a unifying framework against which the potential of nutrigenomics-based personalised advice can be assessed. It has uncovered nine archetypical approaches to personalised nutrition advice in terms of their dominant underlying business models. Differentiating features among such business models are the type of information that is used as a basis for personalisation, the definition of the target group, the communication channels that are being adopted, and the partnerships that are built as a part of the business model. Future research should explore the consumer responses to the diversity of “archetypical” business models for personalised nutrition advice as a source of market information on which the delivery of nutrigenomics-based personalised nutrition advice may further build.     

Impact of Dietary Organic Mineral Supplementation on Reproductive Performance,Egg Quality Characteristics,Lipid Oxidation,Ovarian Follicular Development,and Immune Response in Laying Hens Under High Ambient Temperature

Biological Trace Element Research - The objectives of this study were to investigate the impact of dietary organic mineral mixture (manganese, zinc, and copper) supplementation on reproductive...     

Cell wounding activates phospholipase D in primary mouse keratinocytes

Plasma membrane disruptions occur in mechanically active tissues such as the epidermis and can lead to cell death if the damage remains unrepaired. Repair occurs through fusion of vesicle patches to the damaged membrane region. The enzyme phospholipase D (PLD) is involved in membrane traffickiing; therefore, the role of PLD in membrane repair was investigated. Generation of membrane disruptions by lifting epidermal keratinocytes from the substratum induced PLD activation, whereas removal of cells from the substratum via trypsinization had no effect. Pretreatment with 1,25-dihydroxyvitamin D₃, previously shown to increase PLD1 expression and activity, had no effect on, and a PLD2-selective (but not a PLD1-selective) inhibitor decreased, cell lifting-induced PLD activation, suggesting PLD2 as the isoform activated. PLD2 interacts functionally with the glycerol channel aquaporin-3 (AQP3) to produce phosphatidylglycerol (PG); however, wounding resulted in decreased PG production, suggesting a potential PG deficiency in wounded cells. Cell lifting-induced PLD activation was transient, consistent with a possible role in membrane repair, and PLD inhibitors inhibited membrane resealing upon laser injury. In an in vivo full-thickness mouse skin wound model, PG accelerated wound healing. These results suggest that PLD and the PLD2/AQP3 signaling module may be involved in membrane repair and wound healing.     

Sequencing,Annotation, and Characterization of the Influenza Ferret Infectome

Ferrets have become an indispensable tool in the understanding of influenza virus virulence and pathogenesis. Furthermore, ferrets are the preferred preclinical model for influenza vaccine and therapeutic testing. Here we characterized the influenza infectome during the different stages of the infectious process in ferrets with and without prior specific immunity to influenza. RNA from lung tissue and lymph nodes from infected and naïve animals was subjected to next-generation sequencing, followed by de novo data assembly and annotation of the resulting sequences; this process generated a library comprising 13,202 ferret mRNAs. Gene expression profiles during pandemic H1N1 (pdmH1N1) influenza virus infection were analyzed by digital gene expression and solid support microarrays. As expected during primary infection, innate immune responses were triggered in the lung tissue; meanwhile, in the lymphoid tissue, genes encoding antigen presentation and maturation of effector cells of adaptive immunity increased dramatically. After 5 days postinfection, the innate immune gene expression was replaced by the adaptive immune response, which correlates with viral clearance. Reinfection with homologous pandemic influenza virus resulted in a diminished innate immune response, early adaptive immune gene regulation, and a reduction in clinical severity. The fully annotated ferret infectome will be a critical aid to the understanding of the molecular events that regulate disease severity and host-influenza virus interactions among seasonal, pandemic, and highly pathogenic avian influenzas.