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Japanese students' lack of English writing skills has been a long-standing problem. It not only originates from students' lack of grammatical knowledge and vocabulary, but also from the availability of fewer opportunities to write essays in English. Further, the current standards for evaluating the essays written by Japanese beginner-level learners in English are not established sufficiently, resulting in a heavy grading burden on the teachers. This study establishes an evaluation standard to assess the English essays written by Japanese beginner-level English learners. An "analytic scoring" is conducted for each essay, involving criteria ranging from level 1 to 4, while another group of evaluators perform a "holistic scoring", judging the quality based on their overall impression, on a scale from 1 to 4. The reliability and validity of the "analytic scoring" are established through the correlation analysis of both evaluations. Text mining is used to analyze the explanation of reasons provided by the holistic scoring evaluators to the highest-rated essays and identify the factors determining the quality of English writing. [ABSTRACT FROM AUTHOR]

Background: Transposon-mediated transgenesis is an excellent method for creating stable transgenic lines and insertional mutants. In the chordate Ciona intestinalis, Minos is the only transposon that has been used as the tool for germline transformation. Adding another transposon system in this organism enables us to conduct genetic techniques which can only be realized with the use of two transposons. Results: In the present study, we found that another Tc1/ mariner superfamily transposon, sleeping beauty (SB), retains sufficient activity for germline transformation of C. intestinalis. SB shows efficiencies of germline transformation, insertion into gene coding regions, and enhancer detection comparable to those of Minos. We have developed a system for the remobilization of SB copies in the C. intestinalis genome by using transgenic lines expressing SB transposase in the germ cells. With this system, we examined the manner of SB mobilization in the C. intestinalis genome. SB shows intrachromosomal transposition more frequently than Minos. Conclusions: SB-based germline transformation and the establishment of a new method that uses its frequent intrachromosomal transposition will result in breakthroughs in genetic approaches that use C. intestinalis together with Minos. Developmental Dynamics 242:30-43, 2013. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Metamorphosis, a widespread life history strategy in metazoans, allows dispersal and use of different ecological niches through a dramatic body change from a larval stage [ 1 , 2 ]. Despite its conservation and importance, the molecular mechanisms underlying its initiation and progression have been characterized in only a few animal models. In this study, through pharmacological and gene functional analyses, we identified neurotransmitters responsible for metamorphosis of the ascidian Ciona. Ciona metamorphosis converts swimming tadpole larvae into vase-like, sessile adults. Here, we show that the neurotransmitter GABA is a key regulator of metamorphosis. We found that gonadotropin-releasing hormone (GnRH) is a downstream neuropeptide of GABA. Although GABA is generally thought of as an inhibitory neurotransmitter, we found that it positively regulates secretion of GnRH through the metabotropic GABA receptor during Ciona metamorphosis. GnRH is necessary for reproductive maturation in vertebrates, and GABA is an important excitatory regulator of GnRH in the hypothalamus during puberty [ 3 , 4 ]. Our findings reveal another role of the GABA-GnRH axis in the regulation of post-embryonic development in chordates. • The neurotransmitter GABA is a key regulator of Ciona metamorphosis • Gonadotropin-releasing hormone (GnRH) is the downstream neuropeptide of GABA • GABA positively regulates secretion of GnRH through the metabotropic GABA receptor Metamorphosis is a dramatic body change in metazoans that allows the use of different ecological niches. Hozumi et al. show that GABA is a key regulator of metamorphosis in the ascidian Ciona. During this process, GABA, generally thought of as an inhibitory neurotransmitter, positively regulates secretion of the neuropeptide GnRH. [ABSTRACT FROM AUTHOR]

Maternal mRNAs play crucial roles during early embryogenesis of ascidians, but their functions are largely unknown. In this study, we developed a new method to specifically knockdown maternal mRNAs in Ciona intestinalis using transposon-mediated transgenesis. We found that GFP expression is epigenetically silenced in Ciona intestinalis oocytes and eggs, and this epigenetic silencing of GFP was used to develop the knockdown method. When the 5' upstream promoter and 5' untranslated region (UTR) of a maternal gene are used to drive GFP in eggs, the maternal gene is specifically knocked down together with GFP. The 5' UTR of the maternal gene is the major element that determines the target gene silencing. Zygotic transcription of the target gene is unaffected, suggesting that the observed phenotypes specifically reflect the maternal function of the gene. This new method can provide breakthroughs in studying the functions of maternal mRNAs.

An important way to keep transgenic and mutant lines of the ascidian Ciona intestinalis, a model system for e.g. genetic functions, in laboratories is via culturing systems. Here we report a disease of C. intestinalis observed in an inland culturing system. The disease, called 'long feces syndrome,' is expressed in affected animals by the following characteristic symptoms of the digestive system: (1) excretion of long and thin feces, (2) pale color of the stomach, and (3) congestion of the digestive tube by digested material. Severely diseased animals usually die within a week after the first symptoms occur, implying a high risk of this disease for ascidian culturing systems. The digestive tubes of the diseased animals are occupied by the gregarine apicomplexan parasite Lankesteria ascidiae, suggesting that large-scale infection by this parasite is the cause of long feces syndrome.