糖抗原决定簇与异种移植超急性排斥

近年来,免疫抑制和诱导免疫耐受手段的进步和发展,使人体组织和器官移植已成为当前医疗活动的重要部分,特别是治疗慢性器官衰竭的肾、心、肝和肺移植获得了相当的成功。随之而来的是,全球性的可供移植器官来源不足与器官移植需求日益增长的矛盾急待解决。例如在美国需...     

完美中国颌兽(Sinognathus gracilis)头骨化石标本的新观察

通过ＣＴ扫描对完美中国颌兽（犬齿兽科,爬行纲）头骨正型标本进行再研究,实现了无损伤观察化石标本内部结构之目的,发现脑颅内腔的上方有特别长大的三棱柱形的构造,暂解释为额－顶窦。对鳞骨后外侧面的外耳道作了详细观察记述。     

云南厚壳桂属一新种

瘤果厚壳桂新种CryptocaryarolletiiWangetH.Zhu,sp.nov.SpeciesproximaC.maculataeH.W.Li,sedfructumajore,2.5cmdiam,nervislateralibusutrinsecus4~6differtaC.haihanensiMerr.fructugloboso,paniculaexpansa,multifloradiffert.Arbor,usquead20malalRamuliinjuventnte...     

中国产家蚕抗菌肽A基因部分序列的测定

从大肠杆菌感染的家蚕蛹提取RNA,用RT-PCR方法扩增未知抗菌肽基因片段,经过克隆测序,获得了蚕抗菌肽A基因的部分片段164 bp,为制备蚕抗菌肽A基因探针,筛选基因文库打下了基础.     

V型H+-ATPase结构和调控机制的研究现状

V-ATPase存在于所有已知的真核生物中,有极为重要的生理作用.近几年来,对V-ATPase的结构、功能和调控机制的研究进展很快,对复合体的组装有了进一步的认识.对V-ATPase的主要亚基已经完成序列测定及分析,对各亚基生理功能也进行了较为深入的研究.生物化学及分子生物学工作揭示：生物体内以多种方式对编码V-ATPase主要亚基的基因表达和该酶的活力进行调控.     

DNA损伤与细胞周期调控

DNA损伤和损伤后修复可引起细胞周期阻滞,这一事件由三个阶段组成：损伤的识别,损伤信号的传递以及细胞周期阻滞.在某些情况,这种细胞周期阻滞会失效.     

NMDA受体和长时程增强

近年来,N-甲基-D-门冬氨酸（NMDA）受体在突触可塑性形式——长时程增强（long-term potentiation,LTP）中的作用及该受体被激活后的细胞内级联反应备受人们的关注.人们利用拮抗剂技术和基因敲除的方法,对其进行了广泛的研究,并且就LTP的诱导和维持方面获得了一些进展.已获得的这些研究结果为LTP的突触前及突触后机制提供了有力的证据.     

Studies on Highly Efficient Planting of Transgenic Cotton

Foreign insecticidal genes were transferred into 4 upland cotton ( Gossypium hirsutum L. ) cultivars by Agrobacterium-mediated transformation. It was found that planting style has a critical influence on the survival rate of the transgenic plantlets. Direct transplanting, culturing in liquid medium or vermiculite before transplanting were not proper for planting transgenic plantlets. The survival rate was quite low and hardening time was rather long. Graft could greatly enhance the survival rate and efficiently reduced the hardening time, thus paves the way for cotton improvements through genetic engineering and other biotechnology.     

Effects of Altitude on Antioxidative System in Leaves and Roots of Plantago major

Antioxidative systems were investigated in leaves and roots of Plantago major L. which were collected from Mahan Mountain at different altitudes. The content of glutathione (GSH) in reduced form was increased in leaves and roots with the increasing altitude. The activities of peroxidase (POX) and superoxide dismatase superoxide dismutase (SOD) in roots also increased as the altitude was increased, while that in leaves they declined at higher altitude. Analyses of isozymes of SOD and POX in leaves and roots showed that high altitude (3 300 m) induced the SOD isozymes 8 and POX isozyme 5 in roots, which appeared to be required for protection against lower temperature and higher light intensity as altitude was increased. The present study suggested that high altitude had affected differently the antioxidative system in leaves and roots.     

S(yp) Y279和Y304介导了BcrAbl与Grb2等蛋白的结合

利用体外定点突变技术获得Ｓｙｐ Ｙ２７９Ｆ、Ｙ３０４Ｆ和Ｙ５４６Ｆ突变的ｃＤＮＡ, 将这些突变体和野生型Ｓｙｐ 分别构建入ｐＸＭ 真核表达载体, 转入Ｋ５６２ 细胞。经Ｗｅｓｔｅｒｎ 印迹证明, 各转染Ｋ５６２ 细胞中都有Ｓｙｐ 蛋白的表达。免疫沉淀与免疫印迹结果发现ＷＴ、Ｙ２７９Ｆ、Ｙ３０４Ｆ和Ｙ５４６Ｆ等４ 种Ｓｙｐ 在胞内均能直接与ＢｃｒＡｂｌ 结合。体外结合实验结果表明Ｙ３０４Ｆ突变导致了Ｓｙｐ 不能与Ｓｈｃ 结合,Ｙ２７９Ｆ突变则导致了Ｓｙｐ 不能与Ｇｒｂ２ 结合。结论是： 作为“接头蛋白”,Ｓｙｐ 可以介导ＢｃｒＡｂｌ 与Ｓｈｃ 和Ｇｒｂ２ 之间的结合;Ｇｒｂ２ 结合在Ｓｙｐ 的Ｙ２７９ 上,Ｓｈｃ 则结合在Ｓｙｐ的Ｙ３０４ 上