Attacin gene sequence variations in different ecoraces of tasar silkworm Antheraea mylitta

Attacin gene exists as paralogous conversion and is being used for identification of strain variations in insects based on thesequence variation. Hence, a study was undertaken to analyze the sequence variation of the attacin gene isoforms in the tasarsilkworm Anthereae mylitta that exists in the form of different ecoraces depending upon the environment, food plant and location.Comparison of the previously reported attacin sequences with the DNA sequences of attacin A and B genes revealed six aminoacid substitutions among the sequences of the ecoraces which however did not affect the functional domain of Attacin. Thegenerated dendrogram clearly indicated unique branches for each ecorace with two separate gene clusters for attacin A and B. TheSarihan ecorace formed a separate sub-group under both the gene clusters. The present study also revealed the presence ofAttacin_N Superfamily domain exclusively in Exon I separated from the Attacin_C Superfamily domain that was present in Exon IIand part of Exon III, a prominent character of attacin gene. The phylogenetic reconstruction analysis of attacin gene in A.mylittasupported the common evolutionary origin of attacin genes belonging to the Lepidoteran and Dipteran families that formed twoseparate clusters.     

Myosin-18B Promotes the Assembly of Myosin II Stacks for Maturation of Contractile Actomyosin Bundles

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Role of Monoamine Oxidase Type A and B on the Dopamine Metabolism in Discrete Regions of the Primate Brain

The role of monoamine oxidase (MAO) type A and B on the metabolism of dopamine (DA) in discrete regions of the monkey brain was studied. Monkeys were administered (–)-deprenyl (0.25 mg/kg) or clorgyline (1.0 mg/kg) or deprenyl and clorgyline together by intramuscular injections for 8 days. Levels of DA and its metabolites, dihydroxy phenylacetic acid (DOPAC) and homovanillic acid (HVA) were estimated in frontal cortex (FC), motor cortex (MC), occipital cortex (OC), entorhinal cortex (EC), hippocampus (HI), hypothalamus (HY), caudate nucleus (CN), globus pallidus (GP) and substantia nigra (SN). (–)-Deprenyl administration significantly increased DA levels in FC, HY, CN, GP and SN (39–87%). This was accompanied by a reduction in the levels of DOPAC (37–66%) and HVA (27–79%). Clorgyline administration resulted in MAO-A inhibition by more than 87% but failed to increase DA levels in any of the brain regions studied. Combined treatment of (–)-deprenyl and clorgyline inhibited both types of MAO by more than 90% and DA levels were increased (57–245%) in all brain regions studied with a corresponding decrease in the DOPAC (49–83%) and HVA (54–88%) levels. Our results suggest that DA is metabolized preferentially, if not exclusively by MAO-B in some regions of the monkey brain.     

Characterization of guanylate cyclase of rod outer segments of the bovine retina.

Guanylate cyclase (GTP pyrophosphate-lyse (cyclizing), EC 4.6.1.2.) of bovine retinal rod outer segments is almost completely particulate, i.e. associated with rod outer segment membranes. In contrast to particulate guanylate cyclase in other tissues, treatment of rod outer segments with Triton X-100 does not solublize the enzyme but inhibits it. Enzyme activity is dependent on the presence of divalent cation, especially Mn2+ with only poor activation by Mg2+ (10-fold lower) and no activation seen with other cation. Ezpression of maximal activity required Nm2+ and GTP in equimolar concentrations with an apparent Km of 8 . 10(-4) M and V of 10 nmol/min per mg protein. Excess of Mn2+ over that required for the formation of the Mn . GTP complex was inhibitory. Ca2+, Ba2+ and Co2+ inhibited enzyme activity when assayed with the Mn . GTP substrate complex. In the presence of a fixed concentration of 1mM Mn2+, the enzyme exhibited strong negative cooperative interactions with GTP, characterized by an intermediary plateau region in the substrate vs. enzyme activity curve, a curve of downward concavity in the double reciprocal plot and a Hill coefficient of 0.5. Nucleotides such as ITP, ATP and UTP at higher concentrations (1 mM) stimulates activity by 40%. NaN3 has no effect on the guanylate cyclase. It is thus possible that the guanylate cyclase may be regulated in vivo by both the metal : GTP substrate ratio and the free divalent cation concentration as well as by the ATP concentration and thus play an important but yet undefined role in the visual process.     

Likely individuality of the enzymes catalyzing the phosphorylation of choline and ethanolamine.

Dichloroacetate has effects upon hepatic metabolism which are profoundly different from its effects on heart, skeletal muscle, and adipose tissue metabolism. With hepatocytes prepared from meal-fed rats, dichloroacetate was found to activate pyruvate dehydrogenase, to increase the utilization of lactate and pyruvate without effecting an increase in the net utilization of glucose, to increase the rate of fatty acid synthesis, and to decrease slightly [1-¹⁴C]oleate oxidation to ¹⁴CO₂ without decreasing ketone body formation. With hepatocytes isolated from 48-h-starved rats, dichloroacetate was found to activate pyruvate dehydrogenase, to have no influence on net glucose utilization, to inhibit gluconeogenesis slightly with lactate as substrate, and to stimulate gluconeogenesis significantly with alanine as substrate. The stimulation of fatty acid synthesis by dichloroacetate suggests that the activity of pyruvate dehydrogenase can be rate determining for fatty acid synthesis in isolated liver cells. The minor effects of dichloroacetate on gluconeogenesis suggest that the regulation of pyruvate dehydrogenase is only of marginal importance in the control of gluconeogenesis.     

Antagonist-induced, activation function-2-independent estrogen receptor alpha phosphorylation

Estrogen receptor alpha (ERalpha) serine 118 (Ser118) phosphorylation modulates activation function-1 (AF1) function. Correct positioning of helix 12 promotes agonist-dependent recruitment of cyclin-dependent kinase-7 to catalyze this event. In this study we show robust cyclin-dependent kinase-7-independent, AF2 antagonist-induced Ser118 phosphorylation. Estradiol (E2) and ICI-182,780 (ICI-780) induce Ser118 phosphorylation of wild-type ERalpha and either of two helix 12 mutants, suggesting AF2-independent action, probably via shedding of 90-kDa heat shock protein. With E2 treatment, the predominantly nuclear, phosphorylated ERalpha in COS-1 cells is detergent soluble. Although levels of ICI-780-induced phosphorylation are profound, Ser118-phosphorylated ERalpha is aggregated over the nucleus or in the cytoplasm, fractionating with the cell debris and making detection in cleared lysates improbable. Selective ER modulators (SERMs) elicit a mixed response with phosphorylated ERalpha in both detergent-soluble and -insoluble compartments. Apparent ligand-induced loss of ERalpha protein from cleared lysates is thus due to ligand-induced redistribution into the pellet, not degradation. The COS-1 response to ICI-780 can be mimicked in MCF-7 cells treated with a proteasome inhibitor to block authentic ligand-induced degradation. With SERMs and antagonists, the magnitude of Ser118-phosphorylated receptor redistribution into the insoluble fraction of COS-1 cells correlates with the magnitude of authentic ERalpha degradation in MCF-7 cells. A strong inverse correlation with ligand-induced uterotropism in vivo (P < 0.0001) and direct correlation with AF2-independent transrepression of the matrix metalloprotease-1 promoter in endometrial cells in vitro are seen. These data suggest that ligand-induced Ser118 phosphorylation of ERalpha can be AF2 independent. Furthermore, they identify translocation of Ser118-phosphorylated ERalpha out of the nucleus, leading to cytoplasmic aggregation, as an antagonist pathway that may precede receptor degradation.     

A Genome Wide Study of Copy Number Variation Associated with Nasopharyngeal Carcinoma in Malaysian Chinese Identifies CNVs at 11q14.3 and 6p21.3 as Candidate Loci

Background

Nasopharyngeal carcinoma (NPC) is a neoplasm of the epithelial lining of the nasopharynx. Despite various reports linking genomic variants to NPC predisposition, very few reports were done on copy number variations (CNV). CNV is an inherent structural variation that has been found to be involved in cancer predisposition.

Methods

A discovery cohort of Malaysian Chinese descent (NPC patients, n = 140; Healthy controls, n = 256) were genotyped using Illumina^® HumanOmniExpress BeadChip. PennCNV and cnvPartition calling algorithms were applied for CNV calling. Taqman CNV assays and digital PCR were used to validate CNV calls and replicate candidate copy number variant region (CNVR) associations in a follow-up Malaysian Chinese (NPC cases, n = 465; and Healthy controls, n = 677) and Malay cohort (NPC cases, n = 114; Healthy controls, n = 124).

Results

Six putative CNVRs overlapping GRM5, MICA/HCP5/HCG26, LILRB3/LILRA6, DPY19L2, RNase3/RNase2 and GOLPH3 genes were jointly identified by PennCNV and cnvPartition. CNVs overlapping GRM5 and MICA/HCP5/HCG26 were subjected to further validation by Taqman CNV assays and digital PCR. Combined analysis in Malaysian Chinese cohort revealed a strong association at CNVR on chromosome 11q14.3 (P_combined = 1.54x10^-5; odds ratio (OR) = 7.27; 95% CI = 2.96–17.88) overlapping GRM5 and a suggestive association at CNVR on chromosome 6p21.3 (P_combined = 1.29x10^-3; OR = 4.21; 95% CI = 1.75–10.11) overlapping MICA/HCP5/HCG26 genes.

Conclusion

Our results demonstrated the association of CNVs towards NPC susceptibility, implicating a possible role of CNVs in NPC development.     

Use of Random Amplified Polymorphic DNA (RAPD) to study genetic diversity within a population of blackfly, Simulium gravelyi from Palni hills, peninsular India

The genetic variation of local subpopulations (Palni hills, India) of the blackfly Simulium gravelyi was surveyed at different altitudinal locations using random amplified polymorphic DNA (RAPD) analysis. By comparing the similarity of the bands produced by RAPDs, it may be concluded that there is variation within this population. These data suggest that the heterogeneity of band pattern of S. gravelyi steadily increased from low elevation to high elevation. Site 5 (1590 m altitude) was more polymorphic and it differed most from site 1 (290 m). This is established by the ecological diversity and statistical analyses (PCA) and predicting two major ecological factors of conductivity and current velocity. The speciation hypothesis is consistent with the molecular evidence, postulates a high elevational site 5 (1590 m) and a subsequent site 4 (1250 m).