74 research outputs found

    Synchronization in an evolving network

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    In this work we study the dynamics of Kuramoto oscillators on a stochastically evolving network whose evolution is governed by the phases of the individual oscillators and degree distribution. Synchronization is achieved after a threshold connection density is reached. This cumulative effect of topology and dynamics has many real-world implications, where synchronization in a system emerges as a collective property of its components in a self-organizing manner. The synchronous state remains stable as long as the connection density remains above the threshold value, with additional links providing resilience against network fluctuations.Comment: 4 pages, 4 figure

    Genic non-coding microsatellites in the rice genome: characterization, marker design and use in assessing genetic and evolutionary relationships among domesticated groups

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    <p>Abstract</p> <p>Background</p> <p>Completely sequenced plant genomes provide scope for designing a large number of microsatellite markers, which are useful in various aspects of crop breeding and genetic analysis. With the objective of developing genic but non-coding microsatellite (GNMS) markers for the rice (<it>Oryza sativa </it>L.) genome, we characterized the frequency and relative distribution of microsatellite repeat-motifs in 18,935 predicted protein coding genes including 14,308 putative promoter sequences.</p> <p>Results</p> <p>We identified 19,555 perfect GNMS repeats with densities ranging from 306.7/Mb in chromosome 1 to 450/Mb in chromosome 12 with an average of 357.5 GNMS per Mb. The average microsatellite density was maximum in the 5' untranslated regions (UTRs) followed by those in introns, promoters, 3'UTRs and minimum in the coding sequences (CDS). Primers were designed for 17,966 (92%) GNMS repeats, including 4,288 (94%) hypervariable class I types, which were bin-mapped on the rice genome. The GNMS markers were most polymorphic in the intronic region (73.3%) followed by markers in the promoter region (53.3%) and least in the CDS (26.6%). The robust polymerase chain reaction (PCR) amplification efficiency and high polymorphic potential of GNMS markers over genic coding and random genomic microsatellite markers suggest their immediate use in efficient genotyping applications in rice. A set of these markers could assess genetic diversity and establish phylogenetic relationships among domesticated rice cultivar groups. We also demonstrated the usefulness of orthologous and paralogous conserved non-coding microsatellite (CNMS) markers, identified in the putative rice promoter sequences, for comparative physical mapping and understanding of evolutionary and gene regulatory complexities among rice and other members of the grass family. The divergence between long-grained aromatics and subspecies <it>japonica </it>was estimated to be more recent (0.004 Mya) compared to short-grained aromatics from <it>japonica </it>(0.006 Mya) and long-grained aromatics from subspecies <it>indica </it>(0.014 Mya).</p> <p>Conclusion</p> <p>Our analyses showed that GNMS markers with their high polymorphic potential would be preferred candidate functional markers in various marker-based applications in rice genetics, genomics and breeding. The CNMS markers provided encouraging implications for their use in comparative genome mapping and understanding of evolutionary complexities in rice and other members of grass family.</p

    Identification, characterization and utilization of unigene derived microsatellite markers in tea (Camellia sinensis L.)

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    Background: Despite great advances in genomic technology observed in several crop species, the availability of molecular tools such as microsatellite markers has been limited in tea (Camellia sinensis L.). The development of microsatellite markers will have a major impact on genetic analysis, gene mapping and marker assisted breeding. Unigene derived microsatellite (UGMS) markers identified from publicly available sequence database have the advantage of assaying variation in the expressed component of the genome with unique identity and position. Therefore, they can serve as efficient and cost effective alternative markers in such species. Results: Considering the multiple advantages of UGMS markers, 1,223 unigenes were predicted from 2,181 expressed sequence tags (ESTs) of tea (Camellia sinensis L.). A total of 109 (8.9%) unigenes containing 120 SSRs were identified. SSR abundance was one in every 3.55 kb of EST sequences. The microsatellites mainly comprised of di (50.8%), tri (30.8%), tetra (6.6%), penta (7.5%) and few hexa (4.1%) nucleotide repeats. Among the dinucleotide repeats, (GA)n.(TC)n were most abundant (83.6%). Ninety six primer pairs could be designed form 83.5% of SSR containing unigenes. Of these, 61 (63.5%) primer pairs were experimentally validated and used to investigate the genetic diversity among the 34 accessions of different Camellia spp. Fifty one primer pairs (83.6%) were successfully cross transferred to the related species at various levels. Functional annotation of the unigenes containing SSRs was done through gene ontology (GO) characterization. Thirty six (60%) of them revealed significant sequence similarity with the known/putative proteins of Arabidopsis thaliana. Polymorphism information content (PIC) ranged from 0.018 to 0.972 with a mean value of 0.497. The average heterozygosity expected (HE) and observed (Ho) obtained was 0.654 and 0.413 respectively, thereby suggesting highly heterogeneous nature of tea. Further, test for IAM and SMM models for the UGMS loci showed excess heterozygosity and did not show any bottleneck operating in the tea population. Conclusion: UGMS markers identified and characterized in this study provided insight about the abundance and distribution of SSR in the expressed genome of C. sinensis. The identification and validation of 61 new UGMS markers will not only help in intra and inter specific genetic diversity assessment but also be enriching limited microsatellite markers resource in tea. Further, the use of these markers would reduce the cost and facilitate the gene mapping and marker-aided selection in tea. Since, 36 of these UGMS markers correspond to the Arabidopsis protein sequence data with known functions will offer the opportunity to investigate the consequences of SSR polymorphism on gene function

    Pharmacological evaluation for anti-bacterial and anti-inflammatory potential of polymeric microparticles

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    The objective of the study was to evaluate anti-bacterial and anti-Inflammatory activities of polymeric microparticles. In vitro antibacterial activity was performed for prepared microparticles followed by in vivo anti-inflammatory activity on rats. From the present study, it was observed that the microparticles developed were appropriate in their shape and uniform size. The topography of SEM studies revealed that, the microparticles were smooth-surfaced. The result of antibacterial activity indicated that the formulation has not exhibited any zone of inhibition against the various strains of bacteria used for this study. The result of anti-inflammatory activity (Dextran induced paw edema) exhibits that, the formulations possess the inhibitory potential for various inflammatory mediators thereby reduces the inflammation in paws. From the results, it can be concluded that Acacia arabica microparticles is showing significant Anti-inflammatory activity after 6 h than conventional dosage form

    Functionally relevant microsatellites in sugarcane unigenes

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    <p>Abstract</p> <p>Background</p> <p>Unigene sequences constitute a rich source of functionally relevant microsatellites. The present study was undertaken to mine the microsatellites in the available unigene sequences of sugarcane for understanding their constitution in the expressed genic component of its complex polyploid/aneuploid genome, assessing their functional significance <it>in silico</it>, determining the extent of allelic diversity at the microsatellite loci and for evaluating their utility in large-scale genotyping applications in sugarcane.</p> <p>Results</p> <p>The average frequency of perfect microsatellite was 1/10.9 kb, while it was 1/44.3 kb for the long and hypervariable class I repeats. GC-rich trinucleotides coding for alanine and the GA-rich dinucleotides were the most abundant microsatellite classes. Out of 15,594 unigenes mined in the study, 767 contained microsatellite repeats and for 672 of these putative functions were determined <it>in silico</it>. The microsatellite repeats were found in the functional domains of proteins encoded by 364 unigenes. Its significance was assessed by establishing the structure-function relationship for the beta-amylase and protein kinase encoding unigenes having repeats in the catalytic domains. A total of 726 allelic variants (7.42 alleles per locus) with different repeat lengths were captured precisely for a set of 47 fluorescent dye labeled primers in 36 sugarcane genotypes and five cereal species using the automated fragment analysis system, which suggested the utility of designed primers for rapid, large-scale and high-throughput genotyping applications in sugarcane. Pair-wise similarity ranging from 0.33 to 0.84 with an average of 0.40 revealed a broad genetic base of the Indian varieties in respect of functionally relevant regions of the large and complex sugarcane genome.</p> <p>Conclusion</p> <p>Microsatellite repeats were present in 4.92% of sugarcane unigenes, for most (87.6%) of which functions were determined <it>in silico</it>. High level of allelic diversity in repeats including those present in the functional domains of proteins encoded by the unigenes demonstrated their use in assay of useful variation in the genic component of complex polyploid sugarcane genome.</p

    India’s evergreen revolution in cereals

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    The term ‘Green Revolution’ (GR) is used to highlight an unprecedented increase in wheat production in India during 1968–72. The critics of GR allege that there is technology fatigue, especially after 1980s. The present study was undertaken to analyse the trends in productivity of major cereals and compare yield gains during the GR era and post-GR era. The period of 68 years since 1950 was divided in four phases: pre-GR era (1950–66) referred to as phase I, GR era (1967–83) as phase II, post-GR era of 1984–2000 as phase III and post-GR era of 2001–17 as phase IV. The annual rate of gain in productivity (kg/ha/yr) in each phase was estimated by linear regression. The annual gain in wheat productivity in phase III (53.1 kg/ha) was 30% higher than that in the GR era (41.0 kg/ha). In rice, the productivity gains increased consistently: annual gain in phase III (32.3 kg/ha) and phase IV (41.6 kg/ha) was 68% to 117% respectively, higher than that in the GR era (19.2 kg/ha). The rate of gain in productivity of maize and pearl millet in phases III and IV was 188–530% higher in comparison to the GR phase. The progress can largely be attributed to development and adoption of improved cultivars with higher yield potential and crop management technologies. The analysis provided conclusive evidence of India experiencing evergreen revolution in major cereals

    In Vitro Antidiabetic Effect of Neohesperidin

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    Objective: The present study was performed to determine in vitro antidiabetic effect of neohesperidin. To evaluate inhibitory effect of neohesperidin on α-amylase and α-glucosidase diabetes causing enzyme. Methods and Materials: Invitro carbohydrate metabolizing enzyme based inhibitory methods were used to determine antidiabetic effect of neohesperidin. Alpha (α)-amylase inhibitory assay was performed using different sources i.e. wheat alpha (α)-amylase enzyme, salivary alpha (α)-amylase and fungal alpha (α)-amylase assay. Alpha (α)-glucosidase inhibitory assay was performed using alpha (α)-glucosidase (B. stearothermophil), alpha (α)-glucosidase rat intestine and alpha (α)-glucosidase from baker’s yeast. Sucrase inhibitory assay from rat small intestine. Result: Neohesperidin possess a potent anti-diabetic by significantly inhibiting alpha amylase activity. Conclusion: It was concluded that enzyme inhibitory activity of neohesperidin shown a significantly higher inhibitory activity on alpha-amylase in comparision to alpha-glucosidase &amp; Sucrase enzymes. Keywords: Neohespiridin, acarbose, alpha-amylase, alpha-glucosidas

    SSR and AFLP based genetic diversity of soybean germplasm differing in photoperiod sensitivity

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    Forty-four soybean genotypes with different photoperiod response were selected after screening of 1000 soybean accessions under artificial condition and were profiled using 40 SSR and 5 AFLP primer pairs. The average polymorphism information content (PIC) for SSR and AFLP marker systems was 0.507 and 0.120, respectively. Clustering of genotypes was done using UPGMA method for SSR and AFLP and correlation was 0.337 and 0.504, respectively. Mantel's correlation coefficients between Jaccard's similarity coefficient and the cophenetic values were fairly high in both the marker systems (SSR = 0.924; AFLP = 0.958) indicating very good fit for the clustering pattern. UPGMA based cluster analysis classified soybean genotypes into four major groups with fairly moderate bootstrap support. These major clusters corresponded with the photoperiod response and place of origin. The results indicate that the photoperiod insensitive genotypes, 11/2/1939 (EC 325097) and MACS 330 would be better choice for broadening the genetic base of soybean for this trait

    Whole Genome Characterization of a Few EMS-Induced Mutants of Upland Rice Variety Nagina 22 Reveals a Staggeringly High Frequency of SNPs Which Show High Phenotypic Plasticity Towards the Wild-Type

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    The Indian initiative, in creating mutant resources for the functional genomics in rice, has been instrumental in the development of 87,000 ethylmethanesulfonate (EMS)-induced mutants, of which 7,000 are in advanced generations. The mutants have been created in the background of Nagina 22, a popular drought- and heat-tolerant upland cultivar. As it is a pregreen revolution cultivar, as many as 573 dwarf mutants identified from this resource could be useful as an alternate source of dwarfing. A total of 541 mutants, including the macromutants and the trait-specific ones, obtained after appropriate screening, are being maintained in the mutant garden. Here, we report on the detailed characterizations of the 541 mutants based on the distinctness, uniformity, and stability (DUS) descriptors at two different locations. About 90% of the mutants were found to be similar to the wild type (WT) with high similarity index (&gt;0.6) at both the locations. All 541 mutants were characterized for chlorophyll and epicuticular wax contents, while a subset of 84 mutants were characterized for their ionomes, namely, phosphorous, silicon, and chloride contents. Genotyping of these mutants with 54 genomewide simple sequence repeat (SSR) markers revealed 93% of the mutants to be either completely identical to WT or nearly identical with just one polymorphic locus. Whole genome resequencing (WGS) of four mutants, which have minimal differences in the SSR fingerprint pattern and DUS characters from the WT, revealed a staggeringly high number of single nucleotide polymorphisms (SNPs) on an average (16,453 per mutant) in the genic sequences. Of these, nearly 50% of the SNPs led to non-synonymous codons, while 30% resulted in synonymous codons. The number of insertions and deletions (InDels) varied from 898 to 2,595, with more than 80% of them being 1–2 bp long. Such a high number of SNPs could pose a serious challenge in identifying gene(s) governing the mutant phenotype by next generation sequencing-based mapping approaches such as Mutmap. From the WGS data of the WT and the mutants, we developed a genic resource of the WT with a novel analysis pipeline. The entire information about this resource along with the panicle architecture of the 493 mutants is made available in a mutant database EMSgardeN22 (http://14.139.229.201/EMSgardeN22)
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