Vegetative propagation of the red alga Rhodochorton purpureum by means of fragments that escape digestion by herbivores

Intertidal populations of the filamentous red alga Rhodochorton purpureujn (Lightf.) Rosenv. (Nemaliales, Acrochaetiaceae) in the Northern Netherlands grow as dense velvety turfs in the understory of large fucalean algae. The small and rather constant size of the turf (1 to 1.5 mm) and the high percentage of 'decapitated' filaments suggest that the turf is continually 'shorn' by herbivores. Two grazing invertebrates were found on the turf: the gastropod Littorina littorea (L.) and the amphipod Gamrnarus salinus Spooner Differences between the 2 grazers in the size of ingested R. purpureum fragments and in the proportion of ingested fragments with intact apices were attributed to differences in their feeding mechanisms. Both species egested live R. purpureum fragments In their faecal pellets. These fragments had the capacity to regenerate into new filaments when cultured in the laboratory. In the field small tufts of R. purpureurn filaments were found on bare substratum, originating from fragments contained in sticky, detritus-rich envelopes, probably faecal pellets. Experiments in unlalgal cultures showed that the regeneratlve capacity of fragments is very high, as it proceeds over d broad range of temperature and light conditions, even in total darkness We conclude that the capacity of R. purpureum fragments to escape digestion by herbivores probably plays an important role in vegetative propagation of the species

I feel bad and look worse than you: Social comparisons moderate the effect of mood on face health judgement

Mood can bias the judgements people make about themselves and how people compare themselves to others. However, it is not yet clear whether mood also affects appearance-based self-evaluations and social comparisons. Given the importance of perceived health status for well-being, we investigated the effect of mood on self-image and social comparisons of healthiness during two versions of a face health judgement task. Thirty participants judged how they felt compared to healthy and unhealthy looking versions of their own (self version) and a stranger’s face (stranger version), after a positive, negative and neutral mood induction. The effect of mood was dependent on self/stranger task order. Although mood did not affect face health judgement for participants who initially judged themselves against their own face, it did affect face health judgement for participants who initially judged themselves in comparison to a stranger’s face. After the positive and negative mood inductions, these participants judged themselves as equivalent to healthier/unhealthier looking versions of their own and stranger’s faces, respectively. Thus, social comparisons of facial healthiness could provide a perceptual measure of state well-being

A new perspective on fungal metabolites:Identification of bioactive compounds from fungi using zebrafish embryogenesis as read-out

There is a constant need for new therapeutic compounds. Fungi have proven to be an excellent, but underexplored source for biologically active compounds with therapeutic potential. Here, we combine mycology, embryology and chemistry by testing secondary metabolites from more than 10,000 species of fungi for biological activity using developing zebrafish (Danio rerio) embryos. Zebrafish development is an excellent model for high-throughput screening. Development is rapid, multiple cell types are assessed simultaneously and embryos are available in high numbers. We found that 1,526 fungal strains produced secondary metabolites with biological activity in the zebrafish bioassay. The active compounds from 39 selected fungi were purified by liquid-liquid extraction and preparative HPLC. 34 compounds were identified by a combination of chemical analyses, including LCMS, UV-Vis spectroscopy/ spectrophotometry, high resolution mass spectrometry and NMR. Our results demonstrate that fungi express a wide variety of biologically active compounds, consisting of both known therapeutic compounds as well as relatively unexplored compounds. Understanding their biological activity in zebrafish may provide insight into underlying biological processes as well as mode of action. Together, this information may provide the first step towards lead compound development for therapeutic drug development

Organ-specific responses during brain death:increased aerobic metabolism in the liver and anaerobic metabolism with decreased perfusion in the kidneys

Hepatic and renal energy status prior to transplantation correlates with graft survival. However, effects of brain death (BD) on organ-specific energy status are largely unknown. We studied metabolism, perfusion, oxygen consumption, and mitochondrial function in the liver and kidneys following BD. BD was induced in mechanically-ventilated rats, inflating an epidurally-placed Fogarty-catheter, with sham-operated rats as controls. A 9.4T-preclinical MRI system measured hourly oxygen availability (BOLD-related R2*) and perfusion (T1-weighted). After 4 hrs, tissue was collected, mitochondria isolated and assessed with high-resolution respirometry. Quantitative proteomics, qPCR, and biochemistry was performed on stored tissue/plasma. Following BD, the liver increased glycolytic gene expression (Pfk-1) with decreased glycogen stores, while the kidneys increased anaerobic- (Ldha) and decreased gluconeogenic-related gene expression (Pck-1). Hepatic oxygen consumption increased, while renal perfusion decreased. ATP levels dropped in both organs while mitochondrial respiration and complex I/ATP synthase activity were unaffected. In conclusion, the liver responds to increased metabolic demands during BD, enhancing aerobic metabolism with functional mitochondria. The kidneys shift towards anaerobic energy production while renal perfusion decreases. Our findings highlight the need for an organ-specific approach to assess and optimise graft quality prior to transplantation, to optimise hepatic metabolic conditions and improve renal perfusion while supporting cellular detoxification