Measurement of the Lepton Mass and an Upper Limit on the Mass Difference between + and -

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A research on land use features in the urban area of Utsunomiya City

text紀要論文 / Departmental Bulletin Paperdepartmental bulletin pape

The transfer of genomic information from DNA to RNA in <i>Oxytricha trifallax</i>.

<p>The physical transition of genomic information from DNA to RNA and back to DNA occurs after mating in the ciliate, <i>Oxytricha trifallax</i>. RNA templates (wavy green line) and piRNAs (green dashes) derive from RNA transcripts of the previous generation’s somatic DNA nanochromosomes before the old somatic nucleus degrades. A mitotic copy of the new, zygotic germline genome provides precursor DNA segments (numbers 1–4) that are retained in the developing somatic nucleus through piRNA associations and rearranged according to the inherited RNA templates. This step sometimes reorders or inverts precursor segments to build the mature DNA molecule. The number of copies of each new nanochromosome is also influenced by the concentration of RNA templates supplied by the previous somatic genome during development. Red rectangles represent telomeres added to the ends of somatic chromosomes. Only one representative nanochromosome (of over 16,000 in <i>Oxytricha</i>) is shown for simplicity, and it derives from a representative locus containing 4 scrambled precursor segments in the germline genome.</p

The change in usage of the term “genome” compared to related terms.

<p>A Google ngram [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006181#pgen.1006181.ref006" target="_blank">6</a>] analysis shows the case-insensitive occurrences of the terms “gene,” “genome,” and “chromosome” in the corpus of books in English from 1920 to 2008. The data are smoothed by a three-year moving average. The term “genome” was coined in 1920 [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006181#pgen.1006181.ref001" target="_blank">1</a>], and many sources, including the Oxford English Dictionary, attribute the word to a portmanteau of the words “gene” and “chromosome,” although this etymology is disputed [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006181#pgen.1006181.ref001" target="_blank">1</a>]. The term took decades to enter popular usage and only achieved its current level of usage by the turn of this century.</p

Transposon Domestication versus Mutualism in Ciliate Genome Rearrangements

<div><p>Ciliated protists rearrange their genomes dramatically during nuclear development via chromosome fragmentation and DNA deletion to produce a trimmer and highly reorganized somatic genome. The deleted portion of the genome includes potentially active transposons or transposon-like sequences that reside in the germline. Three independent studies recently showed that transposase proteins of the DDE/DDD superfamily are indispensible for DNA processing in three distantly related ciliates. In the spirotrich <i>Oxytricha trifallax</i>, high copy-number germline-limited transposons mediate their own excision from the somatic genome but also contribute to programmed genome rearrangement through a remarkable transposon mutualism with the host. By contrast, the genomes of two oligohymenophorean ciliates, <i>Tetrahymena thermophila</i> and <i>Paramecium tetraurelia</i>, encode homologous PiggyBac-like transposases as single-copy genes in both their germline and somatic genomes. These domesticated transposases are essential for deletion of thousands of different internal sequences in these species. This review contrasts the events underlying somatic genome reduction in three different ciliates and considers their evolutionary origins and the relationships among their distinct mechanisms for genome remodeling.</p></div

Nuclear dimorphism and genome rearrangements in ciliates.

<p>A) From left to right: <i>Oxytricha trifallax</i>, <i>Paramecium tetraurelia</i>, <i>Tetrahymena thermophila</i>. DNA is shown in cyan, yellow represents tubulin staining. Images were kindly provided by Wenwen Fang (Princeton University, Princeton), Kensuke Kataoka (IMBA, Vienna), and Janine Beisson (CNRS, Gif sur Yvette). Abbreviations: i = micronucleus, a = macronucleus. In <i>Oxytricha trifallax</i>, two lobes of a macronucleus are connected by a thin nuclear bridge (not visible in the image). B) Genome rearrangements in all ciliates shown include elimination of micronucleus (MIC)-limited sequences (i, purple IES) and chromosome breakage, which in Tetrahymena occurs at specific chromosome breakage sites (labeled c). After religation of the flanking macronuclear (MAC) sequences, Tetrahymena chromosomes undergo endoreplication to produce 50 identical copies. C) DNA unscrambling in Oxytricha involves the reshuffling and occasional inversion of precursor micronuclear (MIC) sequences (numbered blue boxes) to assemble them in the correct macronuclear order.</p

Survey Conducted on Use of Massage Room at Nguyen Dinh Chieu School for the Blind in Vietnam

A survey was conducted from December 21-23, 2000, and August 6-11, 2001 on the 265 patients who visited the massage room. Most visited the massage room once a week with the aim of relieving fatigue. Satisfaction of massage techniques, massager's behavior and the comfort of visiting the facility in the blind school were mostly high.departmental bulletin pape

TBE transposases in Oxytricha are germline-limited sequences and they participate in their own removal.

<p>The encoded transposases of the Tc1/<i>mariner</i> family have a DDE catalytic motif. Cleavage of the germline-limited sequences starts with a 3 nucleotide 5′ overhang at an ANT recognition site; the second target site serves as the integration site <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1003659#pgen.1003659-Williams1" target="_blank">[24]</a>.</p

Transposases in Tetrahymena and Paramecium belong to the PiggyBac family.

<p>As domesticated transposases, they are present as single-copy genes in the micronuclear and macronuclear genomes. After expression from the somatic genome, they facilitate IES excision from the new macronuclear genome. IES removal occurs via a 4-base 5′ protruding end. In Paramecium, all deleted sequences have a TA dinucleotide at both boundaries, whereas Tetrahymena displays no consensus sequence.</p