Triacylglycerol Synthesis Enzymes Mediate Lipid Droplet Growth by Relocalizing from the ER to Lipid Droplets

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Highlights? Triacylglyceride (TG) synthesis is coupled with lipid droplet (LD) growth ? Two LD populations exist: growing LDs, containing TG enzymes, and small LDs ? Specific TG synthesis enzymes move from the ER to LDs through membrane bridges ? LD localization of TG enzymes mediates expansion of a subset of LDs     

A global study of relationships between leaf traits, climate and soil measures of nutrient fertility

Aim This first global quantification of the relationship between leaf traits and soil nutrient fertility reflects the trade‐off between growth and nutrient conservation. The power of soils versus climate in predicting leaf trait values is assessed in bivariate and multivariate analyses and is compared with the distribution of growth forms (as a discrete classification of vegetation) across gradients of soil fertility and climate. Location All continents except for Antarctica. Methods Data on specific leaf area (SLA), leaf N concentration (LNC), leaf P concentration (LPC) and leaf N:P were collected for 474 species distributed across 99 sites (809 records), together with abiotic information from each study site. Individual and combined effects of soils and climate on leaf traits were quantified using maximum likelihood methods. Differences in occurrence of growth form across soil fertility and climate were determined by one‐way ANOVA. Results There was a consistent increase in SLA, LNC and LPC with increasing soil fertility. SLA was related to proxies of N supply, LNC to both soil total N and P and LPC was only related to proxies of P supply. Soil nutrient measures explained more variance in leaf traits among sites than climate in bivariate analysis. Multivariate analysis showed that climate interacted with soil nutrients for SLA and area‐based LNC. Mass‐based LNC and LPC were determined mostly by soil fertility, but soil P was highly correlated to precipitation. Relationships of leaf traits to soil nutrients were stronger than those of growth form versus soil nutrients. In contrast, climate determined distribution of growth form more strongly than it did leaf traits. Main conclusions We provide the first global quantification of the trade‐off between traits associated with growth and resource conservation ‘strategies’ in relation to soil fertility. Precipitation but not temperature affected this trade‐off. Continuous leaf traits might be better predictors of plant responses to nutrient supply than growth form, but growth forms reflect important aspects of plant species distribution with climate.     

RNA Mimicry by the Fap7 Adenylate Kinase in Ribosome Biogenesis

During biogenesis of the 40S and 60S ribosomal subunits, the pre-40S particles are exported to the cytoplasm prior to final cleavage of the 20S pre-rRNA to mature 18S rRNA. Amongst the factors involved in this maturation step, Fap7 is unusual, as it both interacts with ribosomal protein Rps14 and harbors adenylate kinase activity, a function not usually associated with ribonucleoprotein assembly. Human hFap7 also regulates Cajal body assembly and cell cycle progression via the p53–MDM2 pathway. This work presents the functional and structural characterization of the Fap7–Rps14 complex. We report that Fap7 association blocks the RNA binding surface of Rps14 and, conversely, Rps14 binding inhibits adenylate kinase activity of Fap7. In addition, the affinity of Fap7 for Rps14 is higher with bound ADP, whereas ATP hydrolysis dissociates the complex. These results suggest that Fap7 chaperones Rps14 assembly into pre-40S particles via RNA mimicry in an ATP-dependent manner. Incorporation of Rps14 by Fap7 leads to a structural rearrangement of the platform domain necessary for the pre-rRNA to acquire a cleavage competent conformation.     

A Natural Combination Extract of Viscum album L. Containing Both Triterpene Acids and Lectins Is Highly Effective against AML In Vivo

Aqueous Viscum album L. extracts are widely used in complementary cancer medicine. Hydrophobic triterpene acids also possess anti-cancer properties, but due to their low solubility they do not occur in significant amounts in aqueous extracts. Using cyclodextrins we solubilised mistletoe triterpenes (mainly oleanolic acid) and investigated the effect of a mistletoe whole plant extract on human acute myeloid leukaemia cells in vitro, ex vivo and in vivo. Single Viscum album L. extracts containing only solubilised triterpene acids (TT) or lectins (viscum) inhibited cell proliferation and induced apoptosis in a dose-dependent manner in vitro and ex vivo. The combination of viscum and TT extracts (viscumTT) enhanced the induction of apoptosis synergistically. The experiments demonstrated that all three extracts are able to induce apoptosis via caspase-8 and -9 dependent pathways with down-regulation of members of the inhibitor of apoptosis and Bcl-2 families of proteins. Finally, the acute myeloid leukaemia mouse model experiment confirmed the therapeutic effectiveness of viscumTT-treatment resulting in significant tumour weight reduction, comparable to the effect in cytarabine-treated mice. These results suggest that the combination viscumTT may have a potential therapeutic value for the treatment AML.     

Extrakorporale Membranoxygenierung in der Intensivmedizin

Extracorporeal membrane oxygenation (ECMO) represents a valuable tool in the armamentarium of life and organ support measures in intensive care medicine. ECMO is used in fulminant pulmonary failure to prevent acute hypoxia and to allow CO₂ removal (veno-venous ECMO) or, in highly selected cases of acute cardiovascular failure, to maintain organ perfusion and gas exchange and to prevent imminent death (veno-arterial ECMO). The purpose of ECMO is to allow time for intrinsic recovery of the lungs and heart. Alternatively, ECMO can be used as bridging device until a suitable organ for transplantation is available or the implantation of an artificial heart is feasible. ECMO carries a high complication rate and its use should be limited to highly specialized centers. In rare cases, mobile ECMO systems can be used by dedicated teams which allow transportation of critically ill patients over longer distances to specialized institutions. There is no unequivocal evidence from controlled studies that the use of ECMO in adults improves survival in larger cohorts, but its use in selected cases can be life saving. Long-term survivors of ECMO therapy report significant impairments in health-related quality of life (HRQL) when compared to healthy controls. There is, however, a gradual recovery and improvement in HRQL over a prolonged period after discharge from the intensive care unit and severe limitations in cognitive or physical function are rare. The incidence of chronic post-traumatic stress disorder (PTSD) in patients after ECMO can reach up to 30%. PTSD has a major negative impact on HRQL outcomes of ECMO therapy. PTSD or other stress-related disorders need to be diagnosed and adequately treated to allow adequate recovery from the extreme illness these patients have survived.     

Reconstruction of cranial and hyobranchial muscles in the triassic temnospondyl Gerrothorax provides evidence for akinetic suction feeding

The cranial and hyobranchial muscles of the Triassic temnospondyl Gerrothorax have been reconstructed based on direct evidence (spatial limitations, ossified muscle insertion sites on skull, mandible, and hyobranchium) and on phylogenetic reasoning (with extant basal actinopterygians and caudates as bracketing taxa). The skeletal and soft‐anatomical data allow the reconstruction of the feeding strike of this bottom‐dwelling, aquatic temnospondyl. The orientation of the muscle scars on the postglenoid area of the mandible indicates that the depressor mandibulae was indeed used for lowering the mandible and not to raise the skull as supposed previously and implies that the skull including the mandible must have been lifted off the ground during prey capture. It can thus be assumed that Gerrothorax raised the head toward the prey with the jaws still closed. Analogous to the bracketing taxa, subsequent mouth opening was caused by action of the strong epaxial muscles (further elevation of the head) and the depressor mandibulae and rectus cervicis (lowering of the mandible). During mouth opening, the action of the rectus cervicis muscle also rotated the hyobranchial apparatus ventrally and caudally, thus expanding the buccal cavity and causing the inflow of water with the prey through the mouth opening. The strongly developed depressor mandibulae and rectus cervicis, and the well ossified, large quadrate‐articular joint suggest that this action occurred rapidly and that powerful suction was generated. Also, the jaw adductors were well developed and enabled a rapid mouth closure. In contrast to extant caudate larvae and most extant actinopterygians (teleosts), no cranial kinesis was possible in the Gerrothorax skull, and therefore suction feeding was not as elaborate as in these extant forms. This reconstruction may guide future studies of feeding in extinct aquatic tetrapods with ossified hyobranchial apparatus. J. Morphol., 2013. © 2012 Wiley Periodicals, Inc.     

Use of the multi-allelic self-incompatibility gene in apple to assess homozygocity in shoots obtained through haploid induction

 To obtain homozygous genotypes of apple, we have induced haploid development of either the female or the male gametes by parthenogenesis in situ and anther culture, respectively. Of the shoots obtained, which were mainly of a non-haploid nature, some could be derived from fertilised egg cells or from sporophytic anther tissue. In order to select the shoots having a true haploid origin, and thus homozygotes, we decided to use the single multi-allelic self-incompatibility gene as a molecular marker to discriminate homozygous from heterozygous individuals. The rationale behind this approach was that diploid apple cultivars contain 2 different alleles of the S-gene and therefore the haploid induced shoots obtained from them should have only one of the alleles of the single parent. The parental cultivars used were ‘Idared’ (parthenogenesis in situ) and ‘Braeburn’ (androgenesis), and their S-genotypes were known, except for 1 of the ‘Braeburn’S-alleles. To stimulate parthenogenetic development ‘Idared’ styles were pollinated with irradiated ‘Baskatong’ pollen, the S-alleles of the latter (2n) cultivar were also unknown. The cloning and sequence analysis of these 3 unidentified S-alleles, 1 from ‘Braeburn’ and 2 from ‘Baskatong’ is described, and we show that they correspond to the S ₂₄ -, S ₂₆ - and S ₂₇ -alleles. We have optimised a method for analysis of the S-alleles of ‘Idared/Baskatong’- or ‘Braeburn’-derived in vitro plant tissues and have shown that this approach can be applied for the screening of the in vitro shoots for their haploid origin. Received: 18 August 1997 / Accepted: 10 September 1997