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41.
42.
Seven Hox cluster-related genes (Dthox-A to -G) have been isolated from the freshwater triclad Dugesia (G.) tigrina, their
sequence compared to other Hox genes and their expression in intact and regenerating organisms analyzed by whole mount in
situ hybridization. Sequence comparison analyses show high similarities of D. tigrina Hox genes to anterior and medial groups
of coelomate Hox genes. Expression analyses show very early, synchronous, and overlapping expression of Dthox -A, -E, -G and
-F in anterior, posterior and lateral regenerative tissues. At one hour of regeneration all Dthox genes studied showed a neat,
clear expression at the wound boundary. Later, as the blastema grows, the expression area expands to more proximal regions
covering the blastema and the distal postblastema regions. Blastemas formed by intercalary regeneration also show a synchronous
expression of the same Hox genes though the onset of activation is much delayed. The finding that the same set of Hox genes
is synchronously activated in anterior, posterior, intercalary and lateral regeneration is in sharp contrast to its well established
role in specifying antero-posterior pattern during embryonic development. The implications of these results as regards ancestral
versus co-opted roles of Hox genes in development and regeneration are discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
43.
Human T-Cell Leukemia Virus Type 1 Tax Induction of NF-κB Involves Activation of the IκB Kinase α (IKKα) and IKKβ Cellular Kinases 下载免费PDF全文
44.
Engineering increased vitamin C levels in plants by overexpression of a D-galacturonic acid reductase 总被引:18,自引:0,他引:18
Agius F González-Lamothe R Caballero JL Muñoz-Blanco J Botella MA Valpuesta V 《Nature biotechnology》2003,21(2):177-181
L-Ascorbic acid (vitamin C) in fruits and vegetables is an essential component of human nutrition. Surprisingly, only limited information is available about the pathway(s) leading to its biosynthesis in plants. Here, we report the isolation and characterization of GalUR, a gene from strawberry that encodes an NADPH-dependent D-galacturonate reductase. We provide evidence that the biosynthesis of L-ascorbic acid in strawberry fruit occurs through D-galacturonic acid, a principal component of cell wall pectins. Expression of GalUR correlated with changing ascorbic acid content in strawberry fruit during ripening and with variations in ascorbic acid content in fruit of different species of the genus Fragaria. Reduced pectin solubilization in cell walls of transgenic strawberry fruit with decreased expression of an endogenous pectate lyase gene resulted in lower ascorbic acid content. Overexpression of GalUR in Arabidopsis thaliana enhanced vitamin C content two- to threefold, demonstrating the feasibility of engineering increased vitamin C levels in plants using this gene. 相似文献
45.
Haiman Mu Haiwen Liu Jiayi Zhang Jianhua Huang Chen Zhu Yue Lu Yueping Shi Yi Wang 《Journal of cellular and molecular medicine》2019,23(3):2174-2183
In addition to the known antitumour effects of ursolic acid (UA), increasing evidence indicates that this molecule plays a role in cardiac protection. In this study, the effects of ursolic acid on the heart in mice treated with doxorubicin (DOX) were assessed. The results showed that ursolic acid improved left ventrical fractional shortening (LVFS) and left ventrical ejection fraction (LVEF) of the heart, increased nitrogen oxide (NO) levels, inhibited reactive oxygen species (ROS) production and decreased cardiac apoptosis in mice treated with doxorubicin. Mechanistically, ursolic acid increased AKT and endothelial nitric‐oxide synthase (eNOS) phosphorylation levels, and enhanced eNOS expression, while inhibiting doxorubicin induced eNOS uncoupling through NADPH oxidase 4 (NOX4) down‐regulation. These effects of ursolic acid resulted in heart protection from doxorubicin‐induced injury. Therefore, ursolic acid may be considered a potential therapeutic agent for doxorubicin‐associated cardiac toxicity in clinical practice. 相似文献
46.
Meng Xue Mu Fangfang Zhang Zeyu Wu Xinru Gao Tiantian Zhao Fenglan Xue Jianping Duan Yongbo Zhang Haijun 《Plant Cell, Tissue and Organ Culture》2021,146(3):473-482
Plant Cell, Tissue and Organ Culture (PCTOC) - Vitex negundo L. var. cannabifolia (Sieb. et Zucc.) Hand.-Mazz. is an important medicinal plant rich in bioactive compounds. In vitro tissue culture... 相似文献
47.
48.
According to the ultrastructural characteristic observation of the developing male germ cells, spermatogenesis of the crustacean
shrimp, Fenneropenaeus chinensis, is classified into spermatogonia, primary spermatocytes, secondary spermatocyte, four stages of spermatids, and mature sperm.
The basic protein transition during its spermatogenesis is studied by transmission electron microscopy of ammoniacal silver
reaction and immunoelectron microscopical distribution of acetylated histone H4. The results show that basic protein synthesized
in cytoplasm of spermatogonia is transferred into the nucleus with deposition on new duplicated DNA. In the spermatocyte stage,
some nuclear basic protein combined with RNP is transferred into the cytoplasm and is involved in forming the cytoplasmic
vesicle clumps. In the early spermatid, most of the basic protein synthesized in the new spermatid cytoplasm is transferred
into the nucleus, and the chromatin condensed gradually, and the rest is shifted into the pre-acrosomal vacuole. In the middle
spermatid, the nuclear basic protein linked with DNA is acetylated and transferred into the proacrosomal vacuole and assembled
into the acrosomal blastema. At the late spermatid, almost all of the basic protein in the nucleus has been removed into the
acrosome. During the stage from late spermatid to mature sperm, some de novo basic proteins synthesized in the cytoplasm belt
transfer into the nucleus without a membrane and almost all deposit in the periphery to form a supercoating. The remnant histone
H4 accompanied by chromatin fibers is acetylated in the center of the nucleus, leading to relaxed DNA and activated genes
making the nucleus non-condensed. 相似文献
49.
Wu LA Feng J Wang L Mu YD Baker A Donly KJ Harris SE MacDougall M Chen S 《Cell and tissue research》2011,343(3):545-558
Bone morphogenetic protein 2 (Bmp2) is essential for osteoblast differentiation and osteogenesis. Generation of floxed Bmp2 osteoblast cell lines is a valuable tool for studying the effects of Bmp2 on osteoblast differentiation and its signaling pathways during skeletal metabolism. Due to relatively limited sources of
primary osteoblasts, we have developed cell lines that serve as good surrogate models for the study of osteoblast cell differentiation
and bone mineralization. In this study, we established and characterized immortalized mouse floxed Bmp2 osteoblast cell lines. Primary mouse floxed Bmp2 osteoblasts were transfected with pSV3-neo and clonally selected. These transfected cells were verified by PCR and immunohistochemistry.
To determine the genotype and phenotype of the immortalized cells, cell morphology, proliferation, differentiation and mineralization
were analyzed. Also, expression of osteoblast-related gene markers including Runx2, Osx, ATF4, Dlx3, bone sialoprotein, dentin matrix protein 1, osteonectin, osteocalcin and osteopontin were examined by quantitative RT-PCR
and immunohistochemistry. These results showed that immortalized floxed Bmp2 osteoblasts had a higher proliferation rate but preserved their genotypic and phenotypic characteristics similar to the primary
cells. Thus, we, for the first time, describe the development of immortalized mouse floxed Bmp2 osteoblast cell lines and present a useful model to study osteoblast biology mediated by BMP2 and its downstream signaling transduction pathways. 相似文献
50.
Velázquez R Muñoz-Hernández B Arenas R Taylor ML Hernández-Hernández F Manjarrez ME López-Martínez R 《Mycopathologia》2003,156(4):263-267
Blastomycosis is an acute or chronic primary infection of the respiratory system, endemic in North America (United States of America and Canada), Africa and Asia. We report a case in Mexico, in a three years old child who had been born in California and lived in Chicago, U.S.A. The patient presented pulmonary symptoms prior to development of a skin ulcer. Blastomyces dermatitidis was identified by mycological and molecular procedures. The patient was successfully treated with amphotericin B, oral ketoconazole and itraconazole. 相似文献