Turnover of plant lineages shapes herbivore phylogenetic beta diversity along ecological gradients

Understanding drivers of biodiversity patterns is of prime importance in this era of severe environmental crisis. More diverse plant communities have been postulated to represent a larger functional trait‐space, more likely to sustain a diverse assembly of herbivore species. Here, we expand this hypothesis to integrate environmental, functional and phylogenetic variation of plant communities as factors explaining the diversity of lepidopteran assemblages along elevation gradients in the Swiss Western Alps. According to expectations, we found that the association between butterflies and their host plants is highly phylogenetically structured. Multiple regression analyses showed the combined effect of climate, functional traits and phylogenetic diversity in structuring butterfly communities. Furthermore, we provide the first evidence that plant phylogenetic beta diversity is the major driver explaining butterfly phylogenetic beta diversity. Along ecological gradients, the bottom up control of herbivore diversity is thus driven by phylogenetically structured turnover of plant traits as well as environmental variables.     

Axial Diffusivity of the Corona Radiata at 24 Hours Post-Stroke: A New Biomarker for Motor and Global Outcome

Fractional anisotropy (FA) is an effective marker of motor outcome at the chronic stage of stroke yet proves to be less efficient at early time points. This study aims to determine which diffusion metric in which location is the best marker of long-term stroke outcome after thrombolysis with diffusion tensor imaging (DTI) at 24 hours post-stroke. Twenty-eight thrombolyzed patients underwent DTI at 24 hours post-stroke onset. Ipsilesional and contralesional FA, mean (MD), axial (AD), and radial (RD) diffusivities values were calculated in different Regions-of-Interest (ROIs): (1) the white matter underlying the precentral gyrus (M1), (2) the corona radiata (CoRad), (3) the posterior limb of the internal capsule (PLIC) and (4) the cerebral peduncles (CP). NIHSS scores were acquired at admission, day 1, and day 7; modified Rankin Scores (mRS) at 3 months. Significant decreases were found in FA, MD, and AD of the ipsilesional CoRad and M1. MD and AD were also significantly lower in the PLIC. The ratio of ipsi and contralesional AD of the CoRad (CoRad-rAD) was the strongest diffusion parameter correlated with motor NIHSS scores on day 7 and with the mRS at 3 months. A Receiver-Operator Curve analysis yielded a model for the CoRad-rAD to predict good outcome based on upper limb NIHSS motor scores and mRS with high specificity and sensitivity. FA values were not correlated with clinical outcome. In conclusion, axial diffusivity of the CoRad from clinical DTI at 24 hours post-stroke is the most appropriate diffusion metric for quantifying stroke damage to predict outcome, suggesting the importance of early axonal damage.     

CORRESPONDENCE BETWEEN PHYLOGENY AND MORPHOLOGY OF SNOWELLA SPP. AND WORONICHINIA NAEGELIANA,CYANOBACTERIA COMMONLY OCCURRING IN LAKES1

In this study, the first reported isolates of the genera Snowella and Woronichinia were characterized by 16S rRNA gene sequencing and morphological analysis. Phylogenetic studies and sequences for these genera were not available previously. By botanical criteria, the five isolated strains were identified as Snowella litoralis (Häyrén) Komárek et Hindák Snowella rosea (Snow) Elenkin and Woronichinia naegeliana (Unger) Elenkin. This study underlines the identification of freshly isolated cultures, since the Snowella strains lost the colony structure and were not identifiable after extended laboratory cultivation. In the 16S rRNA gene analysis, the Snowella strains formed a monophyletic cluster, which was most closely related to the Woronichinia strain. Thus, our results show that the morphology of the genera Snowella and Woronichinia was in congruence with their phylogeny, and their phylogeny seems to support the traditional botanical classification of these genera. Furthermore, the genera Snowella and Woronichinia occurred commonly and might occasionally be the most abundant cyanobacterial taxa in mainly oligotrophic and mesotrophic Finnish lakes. Woronichinia occurred frequently and also formed blooms in eutrophic Czech reservoirs.     

Ruddy turnstones Arenaria interpres rapidly build pectoral muscle after raptor scares

To cope with changes in the environment, organisms not only show behavioural but also phenotypic adjustments. This is well established for the digestive tract. Here we present a first case of birds adjusting their flight machinery in response to predation risk. In an indoor experiment, ruddy turnstones Arenaria interpres were subjected to an unpredictable daily appearance of either a raptor or a small gull (as a control). Ruddy turnstones experiencing threat induced by a flying raptor model, longer than after similar passage by the gull model, refrained from feeding after this disturbance. Pectoral muscle mass, but not lean mass, responded in a course of a few days to changes in the perceived threat of predation. Pectoral muscle mass increased after raptor scares. Taking the small increases in body mass into account, pectoral muscle mass was 3.6% higher than aerodynamically predicted for constant flight performance. This demonstrates that perceived risk factors may directly affect organ size.     

Methods of tracing hydrogen in polyketide biosynthesis: High field NMR spectroscopy of citrinin produced in a D2O based medium

Penicillium citrinum cultures have been germinated on an H₂O-based medium, resuspended on a D₂O-based medium and treated with [l,2-¹³C₂] acetate. The resulting citrinin (1) has been analysed by²H and¹³C nuclear magnetic resonance spectroscopy and information about the metabolism of hydrogen in citrinin biosynthesis has been deduced.     

Homology of Saccharomyces cerevisiae ADH4 to an iron-activated alcohol dehydrogenase from Zymomonas mobilis

Summary Insertion of the transposable element Ty at the ADH4 locus results in increased levels of a new alcohol dehydrogenase (ADH) activity in Saccharomyces cerevisiae. The DNA sequence of this locus has been determined. It contains a long open reading frame which is not homologous to the other ADH isozymes that have been characterized in S. cerevisiae nor does it show obvious homology to Drosophila ADH. The hypothetical ADH does, however, show strong homology to the sequence of an iron-activated ADH from the bacterium Zymomonas mobilis. Thus ADH4 appears to encode an ADH structural gene which, along with the Zymomonas enzyme, may define a new family of alcohol dehydrogenases.Now The Plant Cell Research Institute, Inc., 6560 Trinity Court, Dublin, CA 94568, USA     

Calcium Dependence of Vasoactive Intestinal Peptide-Stimulated Cyclic AMP Accumulation in Rat Hippocampal Slices

Previous work has shown that incubation of hippocampal slices in medium without added calcium markedly attenuates the capacity of vasoactive intestinal peptide (VIP) to elevate cyclic AMP levels. The present studies examined the mechanism that confers calcium dependence on VIP stimulation of cyclic AMP accumulation in hippocampal slices. Calcium dependence was apparent immediately on slice preparation and was reversible only if calcium ions were added back very early during slice incubation (within 5 min). The cyclic AMP response to VIP was not abolished by preincubating slices in 100 microM adenosine, suggesting that calcium-dependent, VIP-induced release of adenosine does not mediate VIP elevation of cyclic AMP. VIP-stimulated cyclic AMP accumulation was not decreased by agents that block calcium influx (verapamil, nifedipine, magnesium ions), or by calmodulin antagonists (trifluoperazine, calmidozolium). In fact both verapamil (100 microM) and magnesium (14 mM) augmented VIP stimulation of cyclic AMP generation. Incubation of slices with the phosphodiesterase inhibitor 1-methyl-3-isobutylxanthine (MIX) did not affect VIP activation of cyclic AMP accumulation if slices were incubated without added calcium, but MIX did enhance VIP elevation of cyclic AMP content in slices incubated with calcium. Thus calcium dependence of the cyclic AMP response to VIP in hippocampal slices is unlikely to result from VIP-dependent calcium influx, from interactions with calmodulin, or from calcium-inhibited phosphodiesterase(s).(ABSTRACT TRUNCATED AT 250 WORDS)