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Takechi M Takeuchi M Ota KG Nishimura O Mochii M Itomi K Adachi N Takahashi M Fujimoto S Tarui H Okabe M Aizawa S Kuratani S 《Journal of experimental zoology. Part B. Molecular and developmental evolution》2011,316(7):526-546
Because of their crucial phylogenetic positions, hagfishes, sharks, and bichirs are recognized as key taxa in our understanding of vertebrate evolution. The expression patterns of the regulatory genes involved in developmental patterning have been analyzed in the context of evolutionary developmental studies. However, in a survey of public sequence databases, we found that the large-scale sequence data for these taxa are still limited. To address this deficit, we used conventional Sanger DNA sequencing and a next-generation sequencing technology based on 454 GS FLX sequencing to obtain expressed sequence tags (ESTs) of the Japanese inshore hagfish (Eptatretus burgeri; 161,482 ESTs), cloudy catshark (Scyliorhinus torazame; 165,819 ESTs), and gray bichir (Polypterus senegalus; 34,336 ESTs). We deposited the ESTs in a newly constructed database, designated the "Vertebrate TimeCapsule." The ESTs include sequences from genes that can be effectively used in evolutionary developmental studies; for instance, several encode cartilaginous extracellular matrix proteins, which are central to an understanding of the ways in which evolutionary processes affected the skeletal elements, whereas others encode regulatory genes involved in craniofacial development and early embryogenesis. Here, we discuss how hagfishes, sharks, and bichirs contribute to our understanding of vertebrate evolution, we review the current status of the publicly available sequence data for these three taxa, and we introduce our EST projects and newly developed database. 相似文献
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Hiroki Tanabe Tomonobu Sato Jiro Watari Atsuo Maemoto Mikihiko Fijiya Toru Kono Toshifumi Ashida Tokiyoshi Ayabe Yutaka Kohgo 《Helicobacter》2008,13(5):370-379
Background and Aims: Chronic gastritis is caused by Helicobacter pylori infection, and gastritis is classified as inflammation, atrophy, and intestinal metaplasia. Detailed pathologic studies have shown that H. pylori settles on the surface of gastric mucosa, and that it is eliminated from metaplastic mucosa. However, its mechanism of natural protection is not well known.
Methods: Antimicrobial human enteric defensin expression was determined in the RNA and protein levels. Recombinant enteric defensins were produced with a bacterial expression system and their anti- H. pylori activities were assessed by bactericidal assay.
Results: Human enteric defensin (HD)-5 and HD-6 were detected in Paneth cells, which are observed in the gastric metaplastic mucosa as well as small intestinal epithelia. HD-5 protein was coexpressed with trypsin, which is considered to be an activating enzyme of HD-5. Less H. pylori was observed in the intestinal metaplasia with HD-5 expressing Paneth cells. The recombinant defensins showed killing activity against H. pylori at a low concentration in vitro.
Conclusions: The human defensins that are expressed in the metaplastic Paneth cells eliminate H. pylori . Metaplastic change may be a purposive development of the human stomach. 相似文献
Methods: Antimicrobial human enteric defensin expression was determined in the RNA and protein levels. Recombinant enteric defensins were produced with a bacterial expression system and their anti- H. pylori activities were assessed by bactericidal assay.
Results: Human enteric defensin (HD)-5 and HD-6 were detected in Paneth cells, which are observed in the gastric metaplastic mucosa as well as small intestinal epithelia. HD-5 protein was coexpressed with trypsin, which is considered to be an activating enzyme of HD-5. Less H. pylori was observed in the intestinal metaplasia with HD-5 expressing Paneth cells. The recombinant defensins showed killing activity against H. pylori at a low concentration in vitro.
Conclusions: The human defensins that are expressed in the metaplastic Paneth cells eliminate H. pylori . Metaplastic change may be a purposive development of the human stomach. 相似文献
35.
Background
Recent experimental studies have demonstrated the importance of invasion history for evolutionary formation of community. However, only few theoretical studies on community evolution have focused on such views.Methodology and Principal Findings
We used a tri-trophic food web model to analyze the coevolutionary effects of ecological invasions by a mutant and by a predator and/or resource species of a native consumer species community and found that ecological invasions can lead to various evolutionary histories. The invasion of a predator makes multiple evolutionary community histories possible, and the evolutionary history followed can determine both the invasion success of the predator into the native community and the fate of the community. A slight difference in the timing of an ecological invasion can lead to a greatly different fate. In addition, even greatly different community histories can converge as a result of environmental changes such as a predator trait shift or a productivity change. Furthermore, the changes to the evolutionary history may be irreversible.Conclusions and Significance
Our modeling results suggest that the timing of ecological invasion of a species into a focal community can largely change the evolutionary consequences of the community. Our approach based on adaptive dynamics will be a useful tool to understand the effect of invasion history on evolutionary formation of community. 相似文献36.
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Okada Anzu Okada Takashi Ide Takeshi Itoh Mituaki Tanaka Kunisuke Takaiwa Fumio Toriyama Kinya 《Molecular breeding : new strategies in plant improvement》2003,12(1):61-70
Recombinant Cry j 1, a Japanese cedar pollen allergen, was produced in rice seeds for potential use for oral immunotherapy. Cry j 1 cDNA was divided into two parts, an N-terminal half and a C-terminal half, and each was fused downstream to glutelin GluB-1 gene containing sequences of the promoter, 5 untranslated region and signal peptide. A gene for green fluorescent protein was also fused to the 3 end of the Cry j 1 fragment. Recombinant Cry j 1 of up to 16.6 g per mg total protein of the seeds was expressed in transgenic rice seeds. Although the recombinant Cry j 1 was expected to be accumulated in protein body II because of the employment of glutelin signal peptide, it was demonstrated to be accumulated exclusively in protein body I. The recombinant Cry j 1 was not shown to react with IgE of allergic patients, indicating the reduction of the risk of anaphylactic reaction. These results demonstrate that the transgenic rice seeds with the recombinant Cry j 1 would be useful for the study of oral immunotherapy. 相似文献
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Endoglycoceramidase catalyzes the hydrolysis of the linkage between oligosaccharides and ceramides of various glycosphingolipids. We found that a bacterial strain Corynebacterium sp., isolated from soil, produced endoglycoceramidase both intracellularly and extracellularly. The intracellular enzyme bound to the cell membrane was solubilized with 1% Triton X-100 and purified to homogeneity about 170-fold with 60% recovery. The molecular mass of the enzyme was approximately 65 kDa. The enzyme is most active at pH 5.5-6.5 and stable at pH 3.5-8.0. Various neutral and acidic glycosphingolipids were hydrolyzed by the enzyme in the presence of 0.1% Triton X-100. Ganglio- and lacto-type glycosphingolipids were readily hydrolyzed, but globo-type glycosphingolipids were hydrolyzed slowly. 相似文献
40.
Takahito Tamai Osamu Yamaguchi Shungo Hikoso Toshihiro Takeda Manabu Taneike Takafumi Oka Jota Oyabu Tomokazu Murakawa Hiroyuki Nakayama Yoshihiro Uno Kyoji Horie Kazuhiko Nishida Nahum Sonenberg Ajay M. Shah Junji Takeda Issei Komuro Kinya Otsu 《The Journal of biological chemistry》2013,288(14):10176-10187
Cardiomyocytes proliferate during fetal life but lose their ability to proliferate soon after birth and further increases in cardiac mass are achieved through an increase in cell size or hypertrophy. Mammalian target of rapamycin complex 1 (mTORC1) is critical for cell growth and proliferation. Rheb (Ras homologue enriched in brain) is one of the most important upstream regulators of mTORC1. Here, we attempted to clarify the role of Rheb in the heart using cardiac-specific Rheb-deficient mice (Rheb−/−). Rheb−/− mice died from postnatal day 8 to 10. The heart-to-body weight ratio, an index of cardiomyocyte hypertrophy, in Rheb−/− was lower than that in the control (Rheb+/+) at postnatal day 8. The cell surface area of cardiomyocytes isolated from the mouse hearts increased from postnatal days 5 to 8 in Rheb+/+ mice but not in Rheb−/− mice. Ultrastructural analysis indicated that sarcomere maturation was impaired in Rheb−/− hearts during the neonatal period. Rheb−/− hearts exhibited no difference in the phosphorylation level of S6 or 4E-BP1, downstream of mTORC1 at postnatal day 3 but showed attenuation at postnatal day 5 or 8 compared with the control. Polysome analysis revealed that the mRNA translation activity decreased in Rheb−/− hearts at postnatal day 8. Furthermore, ablation of eukaryotic initiation factor 4E-binding protein 1 in Rheb−/− mice improved mRNA translation, cardiac hypertrophic growth, sarcomere maturation, and survival. Thus, Rheb-dependent mTORC1 activation becomes essential for cardiomyocyte hypertrophic growth after early postnatal period. 相似文献