PROBABLE ATTACHMENT OF THE DOLEROTHECA CAMPANULUM TO A MYELOXYLON-ALETHOPTERIS TYPE FROND

The discovery of pedunculate specimens of pollen organ Dolerotheca in close association with Myeloxylon-type pinnae and Alethopteris-type pinnules provides evidence for the reconstruction of a petrified medullosan frond and the attachment of the microsporangiate fructification. Specimens of Dolerotheca villosa and D. formosa from Middle and Upper Pennsylvanian age strata of North America are borne on slender peduncles with anatomical features and vascularization identical to those of some level in a Myeloxylon-Alethopteris-type frond. Reconstruction of the frond reveals a large, repeatedly dichotomising organ that bears penultimate pinnae and ultimate pinnules in a pinnate arrangement. Examination of pinnules on the surface of coal ball material indicates that they conform to the compression genus Alethopteris. Identical numbers and arrangement of vascular bundles together with identical anatomical features and multicellular hairs indicate that the Dolerotheca campanulum is borne in the position of a penultimate pinna. A reconstruction of the frond with a proposed polled organ attachment is included.     

The Late Endosomal HOPS Complex Anchors Active G-Protein Signaling Essential for Pathogenesis in Magnaporthe oryzae

In Magnaporthe oryzae, the causal ascomycete of the devastating rice blast disease, the conidial germ tube tip must sense and respond to a wide array of requisite cues from the host in order to switch from polarized to isotropic growth, ultimately forming the dome-shaped infection cell known as the appressorium. Although the role for G-protein mediated Cyclic AMP signaling in appressorium formation was first identified almost two decades ago, little is known about the spatio-temporal dynamics of the cascade and how the signal is transmitted through the intracellular network during cell growth and morphogenesis. In this study, we demonstrate that the late endosomal compartments, comprising of a PI3P-rich (Phosphatidylinositol 3-phosphate) highly dynamic tubulo-vesicular network, scaffold active MagA/Gα_S, Rgs1 (a GAP for MagA), Adenylate cyclase and Pth11 (a non-canonical GPCR) in the likely absence of AKAP-like anchors during early pathogenic development in M. oryzae. Loss of HOPS component Vps39 and consequently the late endosomal function caused a disruption of adenylate cyclase localization, cAMP signaling and appressorium formation. Remarkably, exogenous cAMP rescued the appressorium formation defects associated with VPS39 deletion in M. oryzae. We propose that sequestration of key G-protein signaling components on dynamic late endosomes and/or endolysosomes, provides an effective molecular means to compartmentalize and control the spatio-temporal activation and rapid downregulation (likely via vacuolar degradation) of cAMP signaling amidst changing cellular geometry during pathogenic development in M. oryzae.     

Phenylphenalenone-type phytoalexins in banana (Musa species): a comprehensive review for new research directions

Phytochemistry Reviews - Bananas are the most produced and exported fresh fruit globally; but their sustainable production is always under threat owing to their vegetative reproduction method, in...     

Real Time Identification of Drug-Induced Liver Injury (DILI) through Daily Screening of ALT Results: A Prospective Pilot Cohort Study

Objective

Identification of drug-induced liver disease (DILI) is difficult, even among hospitalized patients. The aim of this pilot study was to assess the impact of a specific strategy for DILI screening.

Design

We prospectively compared the number of acute DILI cases identified in one week of a proactive strategy based on centralized elevated ALT values to those identified with a standard of care strategy for 24-week period based on referral cases to the hepatology unit. In the centralized strategy, a designated study biochemist identified patients with ALT greater than 3 times the upper limit of normal values (ULN) and notified the designated hepatologists, who then went to the patients'' wards, analyzed the charts, and if necessary, interviewed the identified patients. During these two periods, patients with possible DILI were included after signing an informed consent in an ongoing European diagnostic study (SAFE-T consortium).

Results

During the 24-week period of the standard strategy, 12 (0.04%) patients out of a total of 28,145 were identified as having possible DILI, and 11 of these accepted to be included in the protocol. During the one-week proactive period, 7 patients out of a total of 1407 inpatients (0.498%) [odds ratio vs. standard = 12.1 (95% CI, 3.9–32.3); P<0.0001] were identified with possible DILI, and 5 were included in the protocol.

Conclusion

A simple strategy based on the daily analysis of cases with ALT >3 ULN by designated biochemists and hepatologists identified 12 times more acute cases of drug-induced liver disease than the standard strategy.This pilot cohort is registered on the number AP-HP P110201/1/08-03-2011 and AFSSAPS B110346-70.     

Plasticity and Epigenetic Inheritance of Centromere-specific Histone H3 (CENP-A)-containing Nucleosome Positioning in the Fission Yeast

Nucleosomes containing the specific histone H3 variant CENP-A mark the centromere locus on each chromatin and initiate kinetochore assembly. For the common type of regional centromeres, little is known in molecular detail of centromeric chromatin organization, its propagation through cell division, and how distinct organization patterns may facilitate kinetochore assembly. Here, we show that in the fission yeast S. pombe, a relatively small number of CENP-A/Cnp1 nucleosomes are found within the centromeric core and that their positioning relative to underlying DNA varies among genetically homogenous cells. Consistent with the flexible positioning of Cnp1 nucleosomes, a large portion of the endogenous centromere is dispensable for its essential activity in mediating chromosome segregation. We present biochemical evidence that Cnp1 occupancy directly correlates with silencing of the underlying reporter genes. Furthermore, using a newly developed pedigree analysis assay, we demonstrated the epigenetic inheritance of Cnp1 positioning and quantified the rate of occasional repositioning of Cnp1 nucleosomes throughout cell generations. Together, our results reveal the plasticity and the epigenetically inheritable nature of centromeric chromatin organization.     

Length‐weight relationship of freshwater fish,Puntius shalynius Yazdani and Talukdar (Cypriniformes: Cyprinidae), in Meghalaya,India

The present investigation gives the length‐weight relationship (LWR) of Puntius shalynius in Meghalaya, India. The samples for the study were collected from Umiam river. The value of the exponent ‘b’ in the LWR was less than 3, with 0.885 for males and 1.616 in females. This shows that the species exhibit allometric growth pattern. There was no difference in LWR between sexes and seasons.     

Systems analysis of chaperone networks in the malarial parasite Plasmodium falciparum

Molecular chaperones participate in the maintenance of cellular protein homeostasis, cell growth and differentiation, signal transduction, and development. Although a vast body of information is available regarding individual chaperones, few studies have attempted a systems level analysis of chaperone function. In this paper, we have constructed a chaperone interaction network for the malarial parasite, Plasmodium falciparum. P. falciparum is responsible for several million deaths every year, and understanding the biology of the parasite is a top priority. The parasite regularly experiences heat shock as part of its life cycle, and chaperones have often been implicated in parasite survival and growth. To better understand the participation of chaperones in cellular processes, we created a parasite chaperone network by combining experimental interactome data with in silico analysis. We used interolog mapping to predict protein-protein interactions for parasite chaperones based on the interactions of corresponding human chaperones. This data was then combined with information derived from existing high-throughput yeast two-hybrid assays. Analysis of the network reveals the broad range of functions regulated by chaperones. The network predicts involvement of chaperones in chromatin remodeling, protein trafficking, and cytoadherence. Importantly, it allows us to make predictions regarding the functions of hypothetical proteins based on their interactions. It allows us to make specific predictions about Hsp70-Hsp40 interactions in the parasite and assign functions to members of the Hsp90 and Hsp100 families. Analysis of the network provides a rational basis for the anti-malarial activity of geldanamycin, a well-known Hsp90 inhibitor. Finally, analysis of the network provides a theoretical basis for further experiments designed toward understanding the involvement of this important class of molecules in parasite biology.     

Changes in CO2 Exchange Rate,Stomatal Conductance,Activities of Photosystems 1 and 2, and Chloroplast Polypeptide Profile Induced by Simulated Acidic Rain

In seedlings of Vigna radiata (L.) R. Wilczek cultivars ADT-1 and CO-5 exposed to acidic showers (H2SO4 : HNO3 : HCl, 4 : 2 : 1, v/v) of different pH (7.0, 5.5, 4.0, and 2.5) for 10 d, net CO2 uptake and stomatal conductance were reduced. The chlorophyll (Chl) a and b contents were reduced but the carotenoid (Car) content increased. In vivo Chl a fluorescence patterns of both the cultivars were altered. No significant change in photosystem (PS) 1 activity was observed except at pH 2.5 where an inhibition was evident. By contrast, PS2 activities declined rapidly with increasing acidity. The room temperature absorption spectra of isolated chloroplasts showed very little changes. SDS-PAGE analysis revealed depletion of 23, 33, and 55 kDa polypeptides. Cultivar CO-5 was more sensitive to acidic rain than cv. ADT-1.     

Dietary ganglioside decreases cholesterol content, caveolin expression and inflammatory mediators in rat intestinal microdomains

Membrane microdomains rich in cholesterol and sphingolipids, including gangliosides (GGs), are known to be important regions for cell signaling and binding sites for various pathogens. Cholesterol depletion inhibits the cellular entry of pathogens and also reduces inflammatory signals by disrupting microdomain structure. Our previous study showed that dietary gangliosides increased total ganglioside incorporation while decreasing cholesterol in the intestinal mucosa. We hypothesized that diet-induced reduction in cholesterol content in the intestinal mucosa disrupts microdomain structure resulting in reduced pro-inflammatory signals. Male weanling Sprague-Dawley rats were fed semipurified diets for 2 weeks. Experimental diets were formulated to include either ganglioside-enriched lipid (GG diet, 0.02% gangliosides [w/w of diet] ) or polyunsaturated fatty acid (PUFA diet, 1% arachidonic acid and 0.5% docosahexaenoic acid, w/w of total fat), in a control diet containing 20% fat. Levels of cholesterol, GG, caveolin, platelet activating factor (PAF), and diglyceride (DG) were measured in the microdomain isolated from the intestinal brush border. The GG diet increased total gangliosides by 50% with a relative increase in GD3 and a relative decrease in GM3. Cholesterol content was also reduced by 23% in the intestinal microdomain. These changes resulted in a significant decrease in the ratio of cholesterol to ganglioside. The GG diet and the PUFA diet were both associated with reduction in caveolin, PAF, and DG content in microdomains, whereas no change occurred in the ganglioside profile of animals fed the PUFA diet. Dietary gangliosides decrease the cholesterol/ganglioside ratio, caveolin, PAF and DG content in microdomains thus exerting a potential anti-inflammatory effect during gut development.