99 research outputs found
Towards the String representation of the dual Abelian Higgs model beyond the London limit
We perform a path-integral analysis of the string representation of the dual
Abelian Higgs (DAH) model beyond the London limit, where the string describing
the vortex of a flux tube has a finite thickness. We show that besides an
additional vortex core contribution to the string tension, a modified Yukawa
interaction appears as a boundary contribution in the type-II dual
superconducting vacuum. In the London limit, the modified Yukawa interaction is
reduced to the Yukawa one.Comment: 13 pages, JHEP3.cls is used, no figures. The version accepted for
publication in JHE
Identical sets of methylated and nonmethylated genes in Ciona intestinalis sperm and muscle cells
BackgroundThe discovery of gene body methylation, which refers to DNA methylation within gene coding region, suggests an as yet unknown role of DNA methylation at actively transcribed genes. In invertebrates, gene bodies are the primary targets of DNA methylation, and only a subset of expressed genes is modified. ResultsHere we investigate the tissue variability of both the global levels and distribution of 5-methylcytosine (5mC) in the sea squirt Ciona intestinalis. We find that global 5mC content of early developmental embryos is high, but is strikingly reduced in body wall tissues. We chose sperm and adult muscle cells, with high and reduced levels of global 5mC respectively, for genome-wide analysis of 5mC targets. By means of CXXC-affinity purification followed by deep sequencing (CAP-seq), and genome-wide bisulfite sequencing (BS-seq), we designated body-methylated and unmethylated genes in each tissue. Surprisingly, body-methylated and unmethylated gene groups are identical in the sperm and muscle cells. Our analysis of microarray expression data shows that gene body methylation is associated with broad expression throughout development. Moreover, transgenic analysis reveals contrasting gene body methylation at an identical gene-promoter combination when integrated at different genomic sites. ConclusionsWe conclude that gene body methylation is not a direct regulator of tissue specific gene expression in C. intestinalis. Our findings reveal constant targeting of gene body methylation irrespective of cell type, and they emphasize a correlation between gene body methylation and ubiquitously expressed genes. Our transgenic experiments suggest that the promoter does not determine the methylation status of the associated gene body
Genomic Approaches Reveal Unexpected Genetic Divergence Within Ciona intestinalis
Abstract. The invertebrate chordate Ciona intestinalis is a widely used model organism in biological research. Individuals from waters ranging from arctic to temperate are morphologically almost indistinguishable. However, we found significant differences in whole genomic DNA sequence between northern European and Pacific C. intestinalis. Intronic and transposon sequences often appear unrelated between these geographic origins and amino acid substitutions in protein coding sequences indicate a divergence time in excess of 20 MYA. This finding suggests the existence of two cryptic species within the present C. intestinalis species. We found five marker loci which distinguish the two genetic forms by PCR. This analysis revealed that specimens from Naples, Italy, have the Pacific-type genome, perhaps due to humanmediated marine transport of species. Despite major genomic divergence, the two forms could be hybridized in the laboratory
CpG methylation is targeted to transcription units in an invertebrate genome
DNA is methylated at the dinucleotide CpG in genomes of a wide range of plants and animals. Among animals, variable patterns of genomic CpG methylation have been described, ranging from undetectable levels (e.g., in Caenorhabditis elegans) to high levels of global methylation in the vertebrates. The most frequent pattern in invertebrate animals, however, is mosaic methylation, comprising domains of methylated DNA interspersed with unmethylated domains. To understand the origin of mosaic DNA methylation patterns, we examined the distribution of DNA methylation in the Ciona intestinalis genome. Bisulfite sequencing and computational analysis revealed methylated domains with sharp boundaries that strongly colocalize with โผ60% of transcription units. By contrast, promoters, intergenic DNA, and transposons are not preferentially targeted by DNA methylation. Methylated transcription units include evolutionarily conserved genes, whereas the most highly expressed genes preferentially belong to the unmethylated fraction. The results lend support to the hypothesis that CpG methylation functions to suppress spurious transcriptional initiation within infrequently transcribed genes
An Efficient Ligation Method in the Making of an in vitro Virus for in vitro Protein Evolution
The โin vitro virusโ is a molecular construct to perform evolutionary protein engineering. The โvirion (=viral particle)โ (mRNA-peptide fusion), is made by bonding a nascent protein with its coding mRNA via puromycin in a test tube for in vitro translation. In this work, the puromycin-linker was attached to mRNA using the Y-ligation, which was a method of two single-strands ligation at the end of a double-stranded stem to make a stem-loop structure. This reaction gave a yield of about 95%. We compared the Y-ligation with two other ligation reactions and showed that the Y-ligation gave the best productivity. An efficient amplification of the in vitro virus with this โviral genomeโ was demonstrated
Lipid residues in ancient pastoralist pottery from Kazakhstan reveal regional differences in cooking practices
The Bronze AgeโIron Age transition in Central Asia (ca. 800 BCE) was a period of significant cultural change that was heavily influenced by greater population interaction and mobility. Indeed, scholars have increasingly emphasized the role that โfood globalization in prehistoryโ has played in defining this period. In the mountain foothills of Kazakhstan, culinary traditions from across Eurasia were combined through the use of Southwest Asian wheat, barley, and livestock (cattle, sheep, and goats) with East Asian foxtail and broomcorn millets. The development of food cultures during this period has been investigated by archaeobotanical and isotopic analysis, yet lipid residues from pottery, which directly represent culinary practices, have not been adequately examined. In this study, lipid residue analysis was conducted on 72 pottery sherds, excavated from three burial mounds and one non-burial, ritual site located in Kazakhstan, dating to ca. 700โ200 BCE. A particularly informative observation was the frequency of miliacin, a biomarker of broomcorn millet, detected in residues that corresponded well with previously published regional differences observed in carbon isotope ratios of human remains that indicate the consumption of C4 plants. This study also demonstrates continuity of Bronze Age dairying traditions into the Iron Age. Finally, this study sheds new light on the diversity of food cultures and mortuary practices in this region, which were not uniform across either space or time
Genome Profiling (GP) Method Based Classification of Insects: Congruence with That of Classical Phenotype-Based One
Ribosomal RNAs have been widely used for identification and classification of species, and have produced data giving new insights into phylogenetic relationships. Recently, multilocus genotyping and even whole genome sequencing-based technologies have been adopted in ambitious comparative biology studies. However, such technologies are still far from routine-use in species classification studies due to their high costs in terms of labor, equipment and consumables.Here, we describe a simple and powerful approach for species classification called genome profiling (GP). The GP method composed of random PCR, temperature gradient gel electrophoresis (TGGE) and computer-aided gel image processing is highly informative and less laborious. For demonstration, we classified 26 species of insects using GP and 18S rDNA-sequencing approaches. The GP method was found to give a better correspondence to the classical phenotype-based approach than did 18S rDNA sequencing employing a congruence value. To our surprise, use of a single probe in GP was sufficient to identify the relationships between the insect species, making this approach more straightforward.The data gathered here, together with those of previous studies show that GP is a simple and powerful method that can be applied for actually universally identifying and classifying species. The current success supported our previous proposal that GP-based web database can be constructible and effective for the global identification/classification of species
Patients' preferences for involvement in treatment decision making in Japan
BACKGROUND: A number of previous studies have suggested that the Japanese have few opportunities to participate in medical decision-making, as a result both of entrenched physician paternalism and national characteristics of dependency and passivity. The hypothesis that Japanese patients would wish to participate in treatment decision-making if adequate information were provided, and the decision to be made was clearly identified, was tested by interview survey. METHODS: The subjects were diabetic patients at a single outpatient clinic in Kyoto. One of three case study vignettes (pneumonia, gangrene or cancer) was randomly assigned to each subject and, employing face-to-face interviews, the subjects were asked what their wishes would be as patients, for treatment information, participation in decision-making and family involvement. RESULTS: 134 patients participated in the study, representing a response rate of 90%. The overall proportions of respondents who preferred active, collaborative, and passive roles were 12%, 71%, and 17%, respectively. Respondents to the cancer vignette were less likely to prefer an active role and were more likely to prefer family involvement in decision-making compared to non-cancer vignette respondents. If a physician's recommendation conflicted with their own wishes, 60% of the respondents for each vignette answered that they would choose to respect the physician's opinion, while few respondents would give the family's preference primary importance. CONCLUSIONS: Our study suggested that a majority of Japanese patients have positive attitudes towards participation in medical decision making if they are fully informed. Physicians will give greater patient satisfaction if they respond to the desire of patients for participation in decision-making
A genome database for a Japanese population of the larvacean Oikopleura dioica
The larvacean Oikopleura dioica is a planktonic chordate, and is tunicate that belongs to the closest relatives to vertebrates. Its simple and transparent body, invariant embryonic cell lineages, and short life cycle of five days make it a promising model organism for developmental biology research. The genome browser OikoBase was established in 2013 using Norwegian O. dioica. However, genome information for other populations is not available, even though many researchers have studied local populations. In the present study, we sequenced using Illumina and PacBio RSII technologies the genome of O. dioica from a southwestern Japanese population that was cultured in our laboratory for three years. The genome of Japanese O. dioica was assembled into 576 scaffold sequences with a total length and N50 length of 56.6 Mb and 1.5 Mb, respectively. A total of 18,743 gene models (transcript models) were predicted in the genome assembly, named as OSKA2016. In addition, 19,277 non-redundant transcripts were assembled using RNA-seq data. The OSKA2016 has global sequence similarity of only 86.5% when compared with the OikoBase, highlighting the sequence difference between the two far distant O. dioica populations on the globe. The genome assembly, transcript assembly, and transcript models were incorporated into ANISEED (https://www.aniseed.cnrs.fr/) for genome browsing and blast searches. Moreover, screening of the male-specific scaffolds revealed that over 2.6 Mb of sequence were included in the male-specific Yregion. The genome and transcriptome resources from two distinct populations will be useful datasets for developmental biology, evolutionary biology, and molecular ecology using this model organism
BMP4 induction of trophoblast from mouse embryonic stem cells in defined culture conditions on laminin
Because mouse embryonic stem cells (mESCs) do not contribute to the formation of extraembryonic placenta when they are injected into blastocysts, it is believed that mESCs do not differentiate into trophoblast whereas human embryonic stem cells (hESCs) can express trophoblast markers when exposed to bone morphogenetic protein 4 (BMP4) in vitro. To test whether mESCs have the potential to differentiate into trophoblast, we assessed the effect of BMP4 on mESCs in a defined monolayer culture condition. The expression of trophoblast-specific transcription factors such as Cdx2, Dlx3, Esx1, Gata3, Hand1, Mash2, and Plx1 was specifically upregulated in the BMP4-treated differentiated cells, and these cells expressed trophoblast markers. These results suggest that BMP4 treatment in defined culture conditions enabled mESCs to differentiate into trophoblast. This differentiation was inhibited by serum or leukemia inhibitory factor, which are generally used for mESC culture. In addition, we studied the mechanism underlying BMP4-directed mESC differentiation into trophoblast. Our results showed that BMP4 activates the Smad pathway in mESCs inducing Cdx2 expression, which plays a crucial role in trophoblast differentiation, through the binding of Smad protein to the Cdx2 genomic enhancer sequence. Our findings imply that there is a common molecular mechanism underlying hESC and mESC differentiation into trophoblast
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