Composition of epicuticular wax of rice,Oryza sativa

Summary The epicuticular wax of rice, varietyRibe, comprised n-alkanes, esters, aldehydes and free alcohols. The nalkanes contained 4 major chain lengths, C₂₇, C₂₉, C₃₁ and C₃₃. Triacontanal and dotriacontanal were the major aldehydes. Octacosanol comprised 89% of the free alcohols. The esters were mainly esters of C₁₆ to C₂₄ acids with C₂₂ to C₃₀ alcohols.This research was supported by the Consiglio Nazionale delle Ricerche, Rome.     

Phase transitions in the assembly of multivalent signalling proteins

Cells are organized on length scales ranging from ?ngstr?m to micrometres. However, the mechanisms by which ?ngstr?m-scale molecular properties are translated to micrometre-scale macroscopic properties are not well understood. Here we show that interactions between diverse synthetic, multivalent macromolecules (including multi-domain proteins and RNA) produce sharp liquid-liquid-demixing phase separations, generating micrometre-sized liquid droplets in aqueous solution. This macroscopic transition corresponds to a molecular transition between small complexes and large, dynamic supramolecular polymers. The concentrations needed for phase transition are directly related to the valency of the interacting species. In the case of the actin-regulatory protein called neural Wiskott-Aldrich syndrome protein (N-WASP) interacting with its established biological partners NCK and phosphorylated nephrin, the phase transition corresponds to a sharp increase in activity towards an actin nucleation factor, the Arp2/3 complex. The transition is governed by the degree of phosphorylation of nephrin, explaining how this property of the system can be controlled to regulatory effect by kinases. The widespread occurrence of multivalent systems suggests that phase transitions may be used to spatially organize and biochemically regulate information throughout biology.     

Characterization of apoptosis induced by marine natural products in non small cell lung cancer A549 cells

The effects of different marine derived agents were studied in A549 cell growth. These drugs induced cell cycle arrest at the G2-M phase associated with the up-regulation of GADD45alpha-gamma and down-regulation of c-Myc. In treated cells, GADD45alpha-gamma and c-Myc were up- and down-regulated, respectively. A cascade of events leading to apoptotic mitochondrial 'intrinsic' pathway was observed in treated cells: (1) dephosphorylation of BAD serine136; (2) BAD dissociation from 14-3-3 followed by its association with BCL-XL; (3) cytochrome c release; (4) caspase-3 activation, and (5) cleavage of vimentin. Caspase(s) inhibitor prevented the formation of cleavage products and, in turn, apoptosis was inhibited through a p53-independent mechanism. Moreover, these compounds did not activate NF-kappaB. Our findings may offer new insights into the mechanisms of action of these agents in A549 cells. The better understanding of their effects might be important to fully exploit the potential of these new drugs.     

X-linked Cornelia de Lange syndrome owing to SMC1L1 mutations

Cornelia de Lange syndrome is a multisystem developmental disorder characterized by facial dysmorphisms, upper limb abnormalities, growth delay and cognitive retardation. Mutations in the NIPBL gene, a component of the cohesin complex, account for approximately half of the affected individuals. We report here that mutations in SMC1L1 (also known as SMC1), which encodes a different subunit of the cohesin complex, are responsible for CdLS in three male members of an affected family and in one sporadic case.     

A semi-automatic computerized analysis of tracks of ciliates

Summary The behavior of Protozoa can be studied by using the ethogram as a conceptual tool capable of giving an almost complete picture of the motor biology of these microorganisms. A new semi-automatic, computerized method for drawing ethograms is described here: it allows a time-saving of about 70%, in comparison with the similar manual procedure. Microorganism movements are photographed by a Pentax LX camera from the screen of a TV monitor, connected to the stereomicroscope by a TV camera, and resolved into single images using a stroboscopic apparatus. The pictorial data are introduced into the computer by means of a digitizing tablet, and the track analysis is performed semi-automatically. The measurements recorded are then processed using a commercial statistics package in order to obtain a general view of the quantitative parameters of each ethogram.