Role of mitochondrial remodeling in programmed cell death in Drosophila melanogaster

The role of mitochondria in Drosophila programmed cell death remains unclear, although certain gene products that regulate cell death seem to be evolutionarily conserved. We find that developmental programmed cell death stimuli in vivo and multiple apoptotic stimuli ex vivo induce dramatic mitochondrial fragmentation upstream of effector caspase activation, phosphatidylserine exposure, and nuclear condensation in Drosophila cells. Unlike genotoxic stress, a lipid cell death mediator induced an increase in mitochondrial contiguity prior to fragmentation of the mitochondria. Using genetic mutants and RNAi-mediated knockdown of drp-1, we find that Drp-1 not only regulates mitochondrial fission in normal cells, but mediates mitochondrial fragmentation during programmed cell death. Mitochondria in drp-1 mutants fail to fragment, resulting in hyperplasia of tissues in vivo and protection of cells from multiple apoptotic stimuli ex vivo. Thus, mitochondrial remodeling is capable of modifying the propensity of cells to undergo death in Drosophila.     

Identification of MFS proteins in sorghum using semantic similarity

The antiporters, uniporters and symporters are the functional classes of MFS that play major role in ions homeostasis, regulation of pumps and channels, membrane structure, transporters activity in tolerance to abiotic stresses. Major facilitator superfamily (MFS) encodes Na⁺/H⁺ antiporter that are considered as being sensors of the molecule transports. A large number of MFS proteins have been identified in several plants, rice, maize, Arabidopsis etc. However, the majority of proteins in sorghum are described as putative, uncharacterized till date. This suggested that identified proteins of MFS in sorghum are far from saturation. Hence, we developed gene ontology (GO) terms semantic similarity based method using GOSemSim measure of R package. As a result, total 2,568 high (100 %) semantic similar orthologous proteins from 7 plant species were obtained. These data were used to predict function of 257 putative uncharacterized proteins from 18 families of MFS in Sorghum. Consequently, the identified proteins belonged to the function of regulation of pumps and channels, membrane structure, transporters activity, ions homeostasis, transporter mechanisms and binding process. These identified functions appear to have a distinct mechanism of salt-stress adaptation in plants. The proposed method will help in further identifying new proteins that can help in the development of agronomically and economically important plants.     

Impact of anthropogenic sources on aerosol iron solubility over the Bay of Bengal and the Arabian Sea

Ambient aerosols collected from the marine atmospheric boundary layer of the Bay of Bengal and the Arabian Sea have been studied to assess the fractional solubility of aerosol iron, defined as Fe_ws (%)?=?Fe_ws/Fe_Tot?×?100; where Fe_Tot is total aerosol iron and Fe_ws is water soluble iron. The mass concentration of Fe_Tot over the two oceanic regions is not significantly different. However, the fractional solubility is 1–2 orders of magnitude higher over the Bay of Bengal (1.4–24%) compared to that over the Arabian Sea (0.02–0.4%). The spatio-temporal variability in Fe_ws (%) is attributed to differences in the nature of the mineral dust over the two oceanic regions. The Arabian Sea receives coarse dust from desert regions; whereas transport of alluvial dust from the Indo-Gangetic Plain is a dominant source to the Bay of Bengal. The poor fractional solubility (<1%) of Fe from mineral dust, hitherto overestimated in the literature, is documented for the Arabian Sea. A significant linear relationship (P-value?<?0.001) between Fe_ws (%), Fe_Tot and nss-SO₄ ^2? over the Bay of Bengal provides evidence for the chemical processing of mineral dust. Furthermore, the role of anthropogenic sources (biomass burning and fossil-fuel combustion) in enhancing the Fe_ws (%) is discernible from the chemical composition of fine mode (PM_2.5) aerosols over the Bay of Bengal. The potential impact of these Fe-dust depositions on phytoplankton carbon fixation and surface ocean biogeochemistry is discussed.     

Divergence of ANF analogs in smooth muscle cell cGMP response and aorta vasorelaxation: evidence for receptor subtypes

ANF analog potencies in stimulating smooth muscle cell cGMP were compared with the ability to relax histamine-constricted rabbit aorta in vitro. ANF[1-28], [5-28], [5-27] and Lys-11[5-28] elevated cGMP and were potent vasorelaxants. ANF[7-23] and Lys-11[7-23] were potent cGMP stimulators but 1000-fold weaker relaxants. Tyr-8[5-27] did not stimulate cGMP synthesis or antagonize the response of the other peptides, yet was a potent vasorelaxant. Crosslinking with 125I-ANF identified bands at 150 and 65 KD by SDS-PAGE. ANF[1-28], Lys-11[7-23] and Tyr-8[5-27] blocked crosslinking at low concentration despite disparate activities. These data support the existence of ANF receptor subtypes and suggest that cGMP elevation alone is not sufficient to promote atrial peptide-induced vasorelaxation.     

C. elegans mutant identification with a one-step whole-genome-sequencing and SNP mapping strategy

Whole-genome sequencing (WGS) is becoming a fast and cost-effective method to pinpoint molecular lesions in mutagenized genetic model systems, such as Caenorhabditis elegans. As mutagenized strains contain a significant mutational load, it is often still necessary to map mutations to a chromosomal interval to elucidate which of the WGS-identified sequence variants is the phenotype-causing one. We describe here our experience in setting up and testing a simple strategy that incorporates a rapid SNP-based mapping step into the WGS procedure. In this strategy, a mutant retrieved from a genetic screen is crossed with a polymorphic C. elegans strain, individual F2 progeny from this cross is selected for the mutant phenotype, the progeny of these F2 animals are pooled and then whole-genome-sequenced. The density of polymorphic SNP markers is decreased in the region of the phenotype-causing sequence variant and therefore enables its identification in the WGS data. As a proof of principle, we use this strategy to identify the molecular lesion in a mutant strain that produces an excess of dopaminergic neurons. We find that the molecular lesion resides in the Pax-6/Eyeless ortholog vab-3. The strategy described here will further reduce the time between mutant isolation and identification of the molecular lesion.     

Multipattern Consensus Regions in Multiple Aligned Protein Sequences and Their Segmentation

Decomposing a biological sequence into its functional regions is an important prerequisite to understand the molecule. Using the multiple alignments of the sequences, we evaluate a segmentation based on the type of statistical variation pattern from each of the aligned sites. To describe such a more general pattern, we introduce multipattern consensus regions as segmented regions based on conserved as well as interdependent patterns. Thus the proposed consensus region considers patterns that are statistically significant and extends a local neighborhood. To show its relevance in protein sequence analysis, a cancer suppressor gene called p53 is examined. The results show significant associations between the detected regions and tendency of mutations, location on the 3D structure, and cancer hereditable factors that can be inferred from human twin studies.[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27]     

Removal of chromium from industrial waste by using eucalyptus bark

Several low cost biomaterials such as baggase, charred rice husk, activated charcoal and eucalyptus bark (EB) were tested for removal of chromium. All the experiments were carried out in batch process with laboratory prepared samples and wastewater obtained from metal finishing section of auto ancillary unit. The adsorbent, which had highest chromium(VI) removal was EB. Influences of chromium concentration, pH, contact time on removal of chromium from effluent was investigated. The adsorption data were fitted well by Freundlich isotherm. The kinetic data were analyzed by using a first order Lagergren kinetic. The Gibbs free energy was obtained for each system and was found to be -1.879 kJ mol(-1) for Cr(VI) and -3.885 kJ mol(-1) for Cr(III) for removal from industrial effluent. The negative value of deltaG0 indicates the feasibility and spontaneous nature of adsorption. The maximum removal of Cr(VI) was observed at pH 2. Adsorption capacity was found to be 45 mg/g of adsorbent, at Cr(VI) concentration in the effluent being 250 mg/l. A waste water sample containing Cr(VI), Cr(III), Mg, and Ca obtained from industrial unit showed satisfactory removal of chromium. The results indicate that eucalyptus bark can be used for the removal of chromium.     

Thermodynamic and breakthrough column studies for the selective sorption of chromium from industrial effluent on activated eucalyptus bark

Studies were carried out on adsorption of Cr(VI) on an adsorbent made from eucalyptus bark. Results revealed that sorption of chromium on activated eucalyptus bark (AEB) was endothermic in nature. Thermodynamic parameters such as the entropy change, enthalpy change and Gibb's free energy change were found out to be 100.97 J mol(-1)K(-1), 33 kJ mol(-1) and -0.737 kJ mol(-1), respectively. Industrial chrome effluent of different chromium concentration at different pH was used as feedstock for the fixed bed adsorption studies. When effluent was fed to the column at low pH of 2, the breakthrough volume increased significantly compared to effluent at higher pH of 4.85. The surface properties of sorbent were characterized by the Scanning electron microscopy, X-ray diffraction technique and Infrared techniques. It was concluded that AEB sorbent column could be used effectively for removal of chromium from industrial effluents by reducing the pH of chrome effluent to two and at optimal column conditions.