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41.
42.
Dylan F. Colli S. Ryan Blood Aparna C. Sankarankutty Frank B. Sachse Michael Frisk William E. Louch Peter M. Kekenes-Huskey 《Biophysical journal》2019,116(8):1386-1393
In mammalian ventricular cardiomyocytes, invaginations of the surface membrane form the transverse tubular system (T-system), which consists of transverse tubules (TTs) that align with sarcomeres and Z-lines as well as longitudinal tubules (LTs) that are present between Z-lines in some species. In many cardiac disease etiologies, the T-system is perturbed, which is believed to promote spatially heterogeneous, dyssynchronous Ca2+ release and inefficient contraction. In general, T-system characterization approaches have been directed primarily at isolated cells and do not detect subcellular T-system heterogeneity. Here, we present MatchedMyo, a matched-filter-based algorithm for subcellular T-system characterization in isolated cardiomyocytes and millimeter-scale myocardial sections. The algorithm utilizes “filters” representative of TTs, LTs, and T-system absence. Application of the algorithm to cardiomyocytes isolated from rat disease models of myocardial infarction (MI), dilated cardiomyopathy induced via aortic banding, and sham surgery confirmed and quantified heterogeneous T-system structure and remodeling. Cardiomyocytes from post-MI hearts exhibited increasing T-system disarray as proximity to the infarct increased. We found significant (p < 0.05, Welch’s t-test) increases in LT density within cardiomyocytes proximal to the infarct (12 ± 3%, data reported as mean ± SD, n = 3) versus sham (4 ± 2%, n = 5), but not distal to the infarct (7 ± 1%, n = 3). The algorithm also detected decreases in TTs within 5° of the myocyte minor axis for isolated aortic banding (36 ± 9%, n = 3) and MI cardiomyocytes located intermediate (37 4%, n = 3) and proximal (34 ± 4%, n = 3) to the infarct versus sham (57 ± 12%, n = 5). Application of bootstrapping to rabbit MI tissue revealed distal sections comprised 18.9 ± 1.0% TTs, whereas proximal sections comprised 10.1 ± 0.8% TTs (p < 0.05), a 46.6% decrease. The matched-filter approach therefore provides a robust and scalable technique for T-system characterization from isolated cells through millimeter-scale myocardial sections. 相似文献
43.
Alex A. Pollen Aparna Bhaduri Madeline G. Andrews Tomasz J. Nowakowski Olivia S. Meyerson Mohammed A. Mostajo-Radji Elizabeth Di Lullo Beatriz Alvarado Melanie Bedolli Max L. Dougherty Ian T. Fiddes Zev N. Kronenberg Joe Shuga Anne A. Leyrat Jay A. West Marina Bershteyn Craig B. Lowe Bryan J. Pavlovic Arnold R. Kriegstein 《Cell》2019,176(4):743-756.e17
44.
Ansuman Panda Debashis Jena Mrinal Kanti Datta Janmejay Parhi Radhakrishnan Kizhakke Veettil Pramod Kumar Pandey 《Zeitschrift fur angewandte Ichthyologie》2019,35(6):1242-1248
The present study explains the intraspecific variation in Indian Hill trout (Barilius bendelisis) on the basis of image based truss network system and D‐loop region of mtDNA. A total of 210 samples were collected from three different rivers (Teesta, Kameng and Myntudu River) of North East India in Indo‐Burma Biodiversity Hotspot. By using the software applications (tpsDig version 2.1 and PAST), a total of 25 morphometric measurements were generated from 10 landmarks. The Analysis of Variance (ANOVA), Factor Analysis (FA) and Discriminate Function Analysis (DFA) showed, out of the total variations, factor 1 explained 46.74% while factor 2 and factor 3 explained 27.14% and 11.92%, respectively. Using these variables 83.33% of the cross‐validated specimens were classified into distinct groups. Analysis of Molecular Variance (AMOVA) and pairwise Fst value for D‐loop region of mtDNA also showed high to medium level of genetic variation among the stocks and within the stocks. We conclude that the observed discrete stocks might be the result of changing environmental conditions in different rivers of the hotspot as the rivers are present at different altitudinal labels. It is also believed that the variation might be due to the construction of barrages across the river which hinder the mixing among the stocks. 相似文献
45.
Manipulation of endogenous trypsin proteinase inhibitor production in Nicotiana attenuata demonstrates their function as antiherbivore defenses 总被引:9,自引:0,他引:9
Evidence for the in planta defensive function of trypsin protease inhibitors (TPIs) comes from observations of enhanced herbivore resistance after heterologous TPI expression or the manipulation of signal cascades that activate numerous defense responses, including TPI production; no studies have altered the expression of an endogenous pi gene to examine defensive function. We isolated two genes with seven- and six-repeat TPI domains from Nicotiana attenuata from the potato (Solanum tuberosum) PI-II family. To determine whether endogenous TPIs in N. attenuata function defensively against the native herbivores, hornworm (Manduca sexta) and mirids (Tupiocoris notatus), we expressed 175 bp of the seven-domain pi from N. attenuata in an antisense orientation in a TPI-producing genotype to reduce TPI expression and expressed the full-length seven-domain pi in a sense orientation under control of a constitutive promoter to restore TPI activity in a natural genotype from Arizona unable to produce TPIs. Constitutive and inducible TPI production in two antisense lines were diminished by 80% to 90% and 33% to 52%, respectively, and sense expression restored 67% of the activity found in the TPI-producing genotype after caterpillar attack in the TPI-deficient A genotype. Hornworm larvae fed on genotypes with low or no TPI activity grew faster, had higher survivorship, and produced heavier pupae than those that fed on genotypes with high TPI activity. T. notatus showed higher preference for genotypes with low or no TPI activity than for genotypes with high TPI levels. We conclude that endogenous TPIs are an effective defense against these native herbivores. 相似文献
46.
Oxidative modification of hepatic mitochondria protein thiols: effect of chronic alcohol consumption
Venkatraman A Landar A Davis AJ Ulasova E Page G Murphy MP Darley-Usmar V Bailey SM 《American journal of physiology. Gastrointestinal and liver physiology》2004,286(4):G521-G527
Redox modification of mitochondrial proteins is thought to play a key role in regulating cellular function, although direct evidence to support this hypothesis is limited. Using an in vivo model of mitochondrial redox stress, ethanol hepatotoxicity, the modification of mitochondrial protein thiols was examined using a proteomics approach. Specific labeling of reduced thiols in the mitochondrion from the livers of control and ethanol-fed rats was achieved by using the thiol reactive compound (4-iodobutyl)triphenylphosphonium (IBTP). This molecule selectively accumulates in the organelle and can be used to identify thiol-containing proteins. Mitochondrial proteins that have been modified are identified by decreased labeling with IBTP using two-dimensional SDS-PAGE followed by immunoblotting with an antibody directed against the triphenylphosphonium moiety of the IBTP molecule. Analyses of these data showed a significant decrease in IBTP labeling of thiols present in specific mitochondria matrix proteins from ethanol-fed rats compared with their corresponding controls. These proteins were identified as the low-K(m) aldehyde dehydrogenase and glucose-regulated protein 78. The decrease in IBTP labeling in aldehyde dehydrogenase was accompanied by a decrease in specific activity of the enzyme. These data demonstrate that mitochondrial protein thiol modification is associated with chronic alcohol intake and might contribute to the pathophysiology associated with hepatic injury. Taken together, we have developed a protocol to chemically tag and select thiol-modified proteins that will greatly enhance efforts to establish posttranslational redox modification of mitochondrial protein in in vivo models of oxidative or nitrosative stress. 相似文献
47.
Direct differentiation of somatic embryos occurs in high-frequency and at high density in response to 1.0 microM TDZ, on different regions-hypocotyl, epicotyl, cotyledonary-node, cotyledons and leaves-of intact seedlings of Azadirachta. One-week-old seedlings on this medium exhibited stress symptoms as visible by the loss of root formation and reduction in the elongation of hypocotyl and epicotyl. Globular somatic embryos were more abundant on hypocotyl, epicotyl, stem tip and leaves. The arrest of embryos at this stage was possibly due to their presence in high density. Well-developed somatic embryos were present on the cotyledons and the cotyledonary-node. These embryos on isolation and transfer to hormone-free medium regenerated readily to form plantlets. The possible role of stress in thidiazuron-induced somatic embryo formation is discussed. 相似文献
48.
In Population Genetics, two populations are distinguished from each other on the basis of the differences in the distributions
of the alleles at the locus or loci under consideration. These differences are measured by a “genetic distance” between the
two populations (not to be confused with genetic distance between two loci, which is based on recombination fractions) and
they play a major role in inferences at the population level. Several measures of genetic distance have been proposed by different
authors (Sanghvi 1953; Cavalli-Sforza and Edwards 1967; Jukes and Cantor 1969; Nei 1972; Kimura 1980; Reynoldset al 1983; reviews in Felsenstein 1991; Nei and Kumar 2000). Most of these measures are actually dissimilarity measures and not
mathematically true distance measures (B-Rao and Majumdar 1999). Independently, and much before the geneticists, statisticians
too were concerned with the idea of distinguishing between two (statistical) populations. In order to discriminate between
two populations on the basis of one or more characters, divergence measures like “Mahalanobis’D
2 statistic” or “Mahalanobis’ generalized distance” (1936) and “Bhattacharyya’s distance” (1943, 1946), Kullback-Leibler’s
divergence measure (1951) etc. have been proposed by statisticians. Mukherjee and Chattopadhyaya (1986) have mentioned measures
based on distances, association between two attributes and discrimination function. There are similarities between the distance
measures defined by applied scientists and by theoreticians. Felsenstein (1985) shows that three of the allele frequency-based
genetic distance measures were anticipated by Bhattacharyya (1946). Nei and Takezaki (1994) have also studied the effectiveness
of several genetic distance measures in the context of phylogenetic analysis, including Bhattacharyya’s distance measure. 相似文献
49.
Sridhar R Perumal PT Etti S Shanmugam G Ponnuswamy MN Prabavathy VR Mathivanan N 《Bioorganic & medicinal chemistry letters》2004,14(24):6035-6040
In a SAR study, we have synthesized a few 1H-pyrazole carboxylate related microbicides using Vilsmeier reagent. The anti-microbial screening results of 1H-pyrazole-3-carboxylate are reported here for the first time. The effect of 1H-pyrazole carboxylates on the mycelial growth of plant pathogenic fungi is revealed. The first X-ray structure in the family of microbicidal 1H-pyrazole-4-carboxylates is presented. 相似文献
50.