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RNA干涉与基因沉默 总被引:28,自引:6,他引:28
双链RNA介导的遗传干涉的机制是1998年发现的,它通过双链RNA的介导特异性地降解相应序列的mRNA,从而导致转录后水平的基因沉默,到目前为止的真菌,拟南芥,线虫,锥虫,水螅,涡虫,果蝇,斑马鱼,小鼠等真核生物中都发现存在这一基因沉默机制,目前的研究表明,RNA干涉与植物中的共抑制(Cosuppression),真菌中的基因压制(quelling)很可能具有共同的基本分子机制,这也说明,很可能在进化的很早期阶段,生物就获得了这种机制,RNA干涉对于抵抗病毒入侵,抑制转座子活动等具有重要作用,对于生物体的发育和基因调控可能也有重要作用。 相似文献
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2006年3月~2007年2月,对福州市区鸟类资源进行调查,共记录鸟类100种,隶属13目30科,其中古北界鸟类40种,东洋界鸟类31种,广布种鸟类29种.调查4个样区中主要鸟类种类和数量的结果表明,福州市鸟类物种多样性指数(Shannon-Wiener Index)为3.4022,其中以浦下洲最高,为2.9590;大梦山的物种多样性指数最低,为2.5308. 相似文献
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INTRODUCTIONPlantshavedevelopedseveralbi0chemicaldefensemechanismsinresp0nsetopath0gensandabioticstress.Fo1l0wingpathogenattack,plantsynthesizephenyl-propaniodpr0ductssuchaslignin,l0wm0l.wt.antimicrobia1comp0undsknownasphyt0alexins,andseveraldefense-relatedproteins.Amongthesepr0teinsare"pathogenesis-relatedproteins"includingthefungalcellwalldegradingenzymeschitinaseandP-1,3-glucanase[1].Endochitinasefromhigherplantscatalyzethehydr0lysis0fchitin,aP-1,4-linkedhomop0lymerofN-acetyl-D-glucos… 相似文献
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TANG Hong 《中国科学C辑(英文版)》2013,(5):391
The series of mini-reviews in this issue highlight the pro-gress and open questions in three important areas in immu-nology, namely impaired central tolerance, senescence of innate cells and the magic adjuvant effect by recombinant flagellin on mucosal vaccines. 相似文献
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We examined the dietary diversity and food intake of Phrynocephalus frontalis, compared the difference of insect diversity in the natural habitats with different lizard densities, and discussed the potential role of this lizard in the desert ecosystem. The results show that: (1) arthropodans of the orders Coleoptera, Hymenoptera and Hemiptera were major dietary components of P. frontalis; (2) coleoptera larvae always formed the predominant component of lizard diets; (3) dietary diversities of P. frontalis were not significantly different between summer and autumn or between the two sexes; (4) the similarity in trophic niches between seasons was 0.756, whereas the similarity in trophic niches between sexes was 0.994; (5) stomach content weight of lizards varied significantly among different seasons, but there was no significant difference in stomach content weight between sexes; (6) insect diversity differed significantly among the groups of the habitat with different degrees of lizard density, and the habitat with moderate lizards density had the highest insect diversity. We infer that P. frontalis prey mainly on insects and change their diet and food intake with season; males and females consumed similar preys in types and weights. As an important predator, P. frontalis could affect the insect community in the arid ecosystem of Hunshandak Desert on the Mongolian Plateau. 相似文献