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51.
Takao Suzuki Maki Moritani Masayasu Yoshino Mitsuhiro Kagami Shoji Iwasaki Kouichi Nishimura Masahiko Akamatsu Masato Kobori Hitoshi Matsushime Masao Kotoh Kiyoshi Furuichi Mitsuo Itakura 《Mammalian genome》2008,19(1):15-25
When the homozygous active form of porcine TGF-β1 transgene (Tgf/Tgf) (under control of the rat glucagon promoter) is introduced into the nonobese diabetic mouse (NOD) genetic background, the
mice develop endocrine and exocrine pancreatic hypoplasia, low serum insulin concentrations, and impaired glucose tolerance.
To identify genetic modifiers of the diabetic phenotypes, we crossed hemizygous NOD-Tgf with DBA/2J mice (D2) or C3H/HeJ mice (C3H) and used the “transgenic mice” for quantitative trait loci (QTL) analysis. Genome-wide
scans of F2-D Tgf/Tgf (D2 × NOD) and F2-C Tgf/Tgf (C3H × NOD), homozygous for the TGF-β1 transgene, identified six statistically significant modifier QTLs: one QTL (Tdn1) in F2-D Tgf/Tgf, and five QTLs (Tcn1 to Tcn5) in F2-C Tgf/Tgf. Tdn1 (Chr 13, LOD = 4.39), and Tcn3 (Chr 2, LOD = 4.94) showed linkage to body weight at 8 weeks of age. Tcn2 (Chr 7, LOD = 4.38) and Tcn4 (Chr 14, LOD = 3.99 and 3.78) showed linkage to blood glucose (BG) concentrations in ipGTT at 30, 0, and 120 min, respectively. Tcn1 (Chr 1, LOD = 4.41) and Tcn5 (Chr 18, LOD = 4.99) showed linkage to serum insulin concentrations in ipGTT at 30 min. Tcn2 includes the candidate gene, uncoupling protein 2 (Ucp2), and shows linkage to Ucp2 mRNA levels in the soleus muscle (LOD = 4.90). Identification of six QTLs for diabetes-related traits in F2-D Tgf/Tgf and F2-C Tgf/Tgf raises the possibility of identifying candidate susceptibility genes and new targets for drug development for human type
2 diabetes.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
52.
In response to osmotic stress, proline is accumulated in many bacterial and plant cells. During various stresses, the yeast
Saccharomyces cerevisiae induces glycerol or trehalose synthesis, but the fluctuations in gene expression and intracellular levels of proline in yeast
are not yet well understood. We previously found that proline protects yeast cells from damage by freezing, oxidative, or
ethanol stress. In this study, we examined the relationships between the gene expression profiles and intracellular contents
of glycerol, trehalose, and proline under stress conditions. When yeast cells were exposed to 1 M sorbitol stress, the expression
of GPD1 encoding glycerol-3-phosphate dehydrogenase is induced, leading to glycerol accumulation. In contrast, in the presence of
9% ethanol, the rapid induction of TPS2 encoding trehalose-6-phosphate phosphatase resulted in trehalose accumulation. We found that intracellular proline levels
did not increase immediately after addition of sorbitol or ethanol. However, the expressions of genes involved in proline
synthesis and degradation did not change during exposure to these stresses. It appears that the elevated proline levels are
due primarily to an increase in proline uptake from a nutrient medium caused by the induction of PUT4. These results suggest that S. cerevisiae cells do not accumulate proline in response to sorbitol or ethanol stress different from other organisms. 相似文献
53.
We examined the roles of Notch signaling and fibroblast growth factors (FGFs) in the gliogenesis of mouse mesencephalic neural crest cells. The present study demonstrated that Notch activation or FGF treatment promotes the differentiation of glia expressing glial fibrillary acidic protein. Notch activation or FGF2 exposure during the first 48 h in culture was critical for glial differentiation. The promotion of gliogenesis by FGF2 was significantly suppressed by the inhibition of Notch signaling using Notch-1 siRNA. These data suggest that FGFs activate Notch signaling and that this activation promotes the gliogenic specification of mouse mesencephalic neural crest cells. Notch activation and FGF treatment have been shown to participate in the chondrogenic specification of these cells [Nakanishi, K., Chan, Y.S., Ito, K., 2007. Notch signaling is required for the chondrogenic specification of mouse mesencephalic neural crest cells. Mech. Dev. 124, 190–203]. Therefore, we analyzed whether or not there were differences between gliogenic and chondrogenic specifications in the downstream pathway of the Notch receptor. Whereas the activation of only the Deltex-mediated pathway was sufficient to promote glial specification, the activation of both RBP-J- and Deltex-dependent pathways was required for chondrogenic specification. These results suggest that the different downstream pathways of the Notch receptor participate in the gliogenic and chondrogenic specification of mouse mesencephalic neural crest cells. 相似文献
54.
Nobuko Tuno Andrew K. Githeko Takeshi Nakayama Noboru Minakawa Masahiro Takagi Guiyun Yan 《Ecological Research》2006,21(3):476-482
Algae are important food resources of the larvae of the African malaria vectors, Anopheles gambiae Giles and Anopheles arabiensis Patton (Anopheles gambiae sensu lato), and other zooplankton, but empirical evidence remains meager about the agal flora in ephemeral water bodies.
The animals present in natural aquatic habitats in western Kenya were sampled from July to November 2002 to study abiotic
and biotic environmental factors determining A. gambiae sl larval abundance. The five highest concentrations of third and fourth instars and pupae (hereafter referred to as old-stage
larvae) were sampled in conjunction with the unicellular epizoic green algae, Rhopalosolen species (Chlorophyta; Chlorophyceae). Canonical correspondence analysis revealed that the presence of Rhopalosolen species was the most important determinant of the animal assemblage. The density of old-stage A. gambiae sl larvae was positively correlated with the presence of Rhopalosolen species, but the density of first and second instars of A. gambiae sl was not. The water bodies with Rhopalosolen sp. yielded larger mosquitoes in spite of the higher density of larvae. We demonstrated that the productivity of water bodies
in terms of the larvae of malaria vectors can differ in magnitude depending on the agal flora. We discuss phytoplankton as
a regulator of mosquito larval populations. 相似文献
55.
Sawada MT Tamura T Mitani Y Kaya M Ito G Hashimoto H Sawada H 《Biochemical and biophysical research communications》2006,349(2):694-700
We previously reported that immature starfish oocytes contain a novel 530-kDa proteasome-associating complex PC500 [previously named PC530; E. Tanaka, M. Takagi Sawada, C. Morinaga, H. Yokosawa, H. Sawada, Isolation and characterization of a novel 530-kDa protein complex (PC 530) capable of associating with the 20S proteasome from star fish oocytes, Arch. Biochem. Biophys. 374 (2000) 181-188]. In the present study, in order to obtain an insight into the biological function of this complex, we investigated the effects of anti-PC500 monoclonal antibodies on oocyte maturation of the starfish Asterina pectinifera. A monoclonal antibody 7C5 strongly inhibited germinal vesicle breakdown (GVBD) in a concentration-dependent manner. In contrast to the inhibitory effect of the 7C5 antibody on GVBD, no inhibition of egg cleavage was observed in a 7C5-antibody-microinjected single blastomere in a 2-cell stage embryo. These results indicate that PC500 plays a key role in starfish oocyte maturation in a meiosis-specific manner. 相似文献
56.
57.
Kudo T Fujii T Ikegami S Inokuchi K Takayama Y Ikehara Y Nishihara S Togayachi A Takahashi S Tachibana K Yuasa S Narimatsu H 《Glycobiology》2007,17(1):1-9
The 3-fucosyl-N-acetyllactosamine [Lewis x (Le(x)), CD15, SSEA-1] carbohydrate structure is expressed on several glycolipids, glycoproteins, and proteoglycans of the nervous system and has been implicated in cell-cell recognition, neurite outgrowth, and neuronal migration during development. To characterize the functional role of Le(x) carbohydrate structure in vivo, we have generated mutant mice that lack alpha1,3-fucosyltransferase IX (Fut9(-/-)). Fut9(-/-) mice were unable to synthesize the Le(x) structure carried on glycoproteins and glycolipids in embryonic and adult brain. However, no obvious pathological differences between wild-type and Fut9(-/-) mice were found in brain. In behavioral tests, Fut9(-/-) mice exhibited increased anxiety-like responses in dark-light preference and in elevated plus maze tests. Immunohistochemical analysis showed that the number of calbindin-positive neurons was decreased in the basolateral amygdala in Fut9(-/-) mice. These observations indicated that the carbohydrates synthesized by Fut9 play critical roles in functional regulations of interneurons in the amygdalar subdivisions and suggested a role for the Le(x) structure in some aspects of emotional behavior in mice. 相似文献
58.
Saito On Kobayashi Tatsuya Hiroi Maiko Kawatsu Masayuki Takagi Shun Nishihiro Jun Kagami Maiko 《Limnology》2019,20(1):21-28
Limnology - Trapa spp. dominate many shallow eutrophic lakes in Japan, which must affect the nutrient dynamics in lakes. Trapa spp. are utilized by several animals, in particular the leaf beetle,... 相似文献
59.
60.
Hiroyoshi Hoshi Yuji Takagi Keizo Kobayashi Masakazu Onodera Taneaki Oikawa 《In vitro cellular & developmental biology. Animal》1991,27(7):578-584
Summary We have developed an improved serum-free medium to optimize the cell growth of bovine granulosa cells. The cells on collagen-coated
culture plates proliferated extensively in a nutrient medium supplemented with insulin, heparin binding growth factor-2 (HBGF-2),
lipoprotein, and bovine serum albumin (BSA). The cell doubling time at logarithmic phase and final cell density at confluent
cultures were equal to those of cultures grown in the presence of medium supplemented with optimal concentration (10%) of
fetal bovine serum (FBS). Whereas HBGF-2 or insulin alone had a small mitogenic effect of granulosa cells, lipoprotein or
BSA did not. When lipoprotein, BSA, or insulin was added together with HBGF-2, synergistic cell proliferation was observed
in all combinations. Insulin or lipoprotein had an additive mitogenic stimulation of these cells in the presence of BSA. After
granulosa cells were subcultivated in a serum-containing medium until three generations [8.5 cumulative population doubling
level (CPDL)], subsequent subcultivation of the cells in a complete serum-free medium could be achieved up to six generations
(14.4 CPDL). These results demonstrate that this serum-free medium can support the optimal cell growth and long-term subcultivation
of bovine granulosa cells. 相似文献