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961.
Generation of cloned transgenic pigs rich in omega-3 fatty acids 总被引:33,自引:0,他引:33
Lai L Kang JX Li R Wang J Witt WT Yong HY Hao Y Wax DM Murphy CN Rieke A Samuel M Linville ML Korte SW Evans RW Starzl TE Prather RS Dai Y 《Nature biotechnology》2006,24(4):435-436
Meat products are generally low in omega-3 (n-3) fatty acids, which are beneficial to human health. We describe the generation of cloned pigs that express a humanized Caenorhabditis elegans gene, fat-1, encoding an n-3 fatty acid desaturase. The hfat-1 transgenic pigs produce high levels of n-3 fatty acids from n-6 analogs, and their tissues have a significantly reduced ratio of n-6/n-3 fatty acids (P < 0.001). 相似文献
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963.
倭竹属地理分布的研究 总被引:2,自引:0,他引:2
倭竹属Shibataea Makino隶于禾本科之竹亚科,现已知有8种,分布于我国东南部的浙江、福建、江苏、安徽、江西等省,广东、台湾两省有少量栽培,日本产1种。苏联、西德、印尼等国所栽培的倭竹均系自我国或日本引入。我国浙-闽地区产8种,且都有野生发现,是本属的现代分布中心。倭竹属植物体型矮小,常植于庭院或公园中供观赏。近年来盆景艺术迅速发展,微型园林日益兴起,倭竹属植物体态优美,常绿,耐寒且易于栽培,为广大园林工作者所垂青。 相似文献
964.
Development of a new xenoestrogen screening system using fission yeast Schizosaccharomyces pombe 总被引:4,自引:0,他引:4
Endocrine disrupters refer to environmental or chemical compounds, which interfere with the endocrine system of organisms. In this study, our aim was to develop a screening method to detect xenoestrogen (an endocrine disrupter that is commonly encountered in our daily life) by using fission yeast Schizosaccharomyces pombe. Although the yeast (the simplest eukaryotic cell) has no endocrine system, estrogen receptors that are created to express in the yeast cell can be activated by estrogen in a similar manner to mammalian cells. First, in order to express the human estrogen receptor (hER) in the yeast cell, we constructed a yeast expression vector that contained hER (pREP42MHN-hER). In the yeast cells that are transformed with the pREP42MHN-hER vector, estrogen receptors could recognize xenoestrogen, which allowed the determination of the presence of xenoestrogen in any given sample. Furthermore, we constructed a yeast strain that contained an estrogen responsive element (ERE) that fused with the Escherichia coli LacZ gene (pERE-LacZ) as a reporter for binding of xenoestrogen with the estrogen receptor. Since this vector system allows determination of the presence and level of xenoestrogen with simple procedures, it is expected that they can serve as an efficient assay system to detect xenoestrogen. 相似文献
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966.
Disruption of the FEN-1/PCNA interaction results in DNA replication defects, pulmonary hypoplasia, pancytopenia, and newborn lethality in mice 下载免费PDF全文
The interaction between flap endonuclease 1 (FEN-1) and proliferation cell nuclear antigen (PCNA) is critical for faithful and efficient Okazaki fragment maturation. In a living cell, this interaction is probably important for PCNA to load FEN-1 to the replication fork, to coordinate the sequential functions of FEN-1 and other enzymes, and to stimulate its enzyme activity. The FEN-1/PCNA interaction is mediated by the motif (337)QGRLDDFFK(345) of FEN-1, such that an F343AF344A (FFAA) mutant cannot bind to PCNA but retains its nuclease activities. To determine the physiological roles of the FEN-1/PCNA interaction in a mammalian system, we knocked the FFAA Fen1 mutation into the Fen1 gene locus of mice. FFAA/FFAA mouse embryo fibroblasts underwent DNA replication and division at a slower pace, and FFAA/FFAA mutant embryos displayed significant defects in growth and development, particularly in the lung and blood systems. All newborn FFAA mutant pups died at birth, likely due to pulmonary hypoplasia and pancytopenia. Collectively, our data demonstrate the importance of the FEN-1/PCNA complex in DNA replication and in the embryonic development of mice. 相似文献
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