中国鲎精子发生的研究:Ⅱ.精子形成

应用电技术研究中国鲎精子形成过程和特点,早期精子细胞核圆,染色质呈网状分布,胞质中有许多线粒体和高尔基液泡,精子形成期间,出现合胞体现象,核分裂而胞质不分裂,细胞通过胞质桥相联系,随后出现隔板,逐渐将细胞核分开。细胞随访核向后移动而呈现极化现象。核的顶部出现一个高尔基－线粒体区,顶体由高在液泡演变而。精子形成期间,核中央位置形成贯穿整个的中央通道,并在核中形成植入窝,中心粒位于其中,成熟精子胞质极     

猫基底前脑胆碱能皮质投射神经元区的P物质样免疫反应神经元

应用免疫组织化学和邻位切片法,研究了猫基底前脑胆碱能皮质投射神经元区的Ｐ物质样免疫反应神经元的分布特征,及其与胆碱乙酰化酶样免疫反应神经元的分布关系,从内侧隔核至Ｍｅｙｎｅｒｔ基底核,２种神经元分布范围相近,且形态,大小相似。但在邻位切片,未见分别呈此二免疫反应的同一神经元的对应剖面。Ｐ物质样免疫反应神经元在内侧隔核和斜角带核数量较多,但在基底核明显减少,在Ｃｈ４间质部及腹侧苍白球连合下部仅为偶见     

Adenovirus-mediated expression of pig α(1,3) galactosyltransferase reconstructs Gal α(1,3) Gal epitope on the surface of human tumor cells

INTRODUCTIONGal a(1, 3) Gal (gal epitope) is a carbohydrate epitope, which is produced in large amounton the cells of pigs, mice and New World monkey(monkey of South America) by the glycosylationenzyme G alal 1 ) 4G IcNAc3- a- D- galactosyltransferase[or(1, 3)GT; EC2.4.1.511111. This enzyme is active in the Golgi appaxatus of cells and transfers galactose from the sugandonor uridine diphoSphate galactose (UDP-galactose) to the acceptor Nacetyllactosamine residue (Galaal-4GlcNAc-R…     

杉木与伴生植物凋落物混合分解的相互作用研究

通过对杉木与9种伴生植物凋落物混合分解特征比较研究表明,8种植物对杉木凋落物的分解均有不同程度的促进作用,其中观音座莲对杉木凋落物分解的促进最大,而木荷对杉木凋落物分解的影响则表现出先有一定程度的促进而后又有微弱的抑制作用,促进大小表现出观音座莲＞杜茎山＞三龙爪＞狗脊＞苎麻＞丝栗栲＞闽粤栲＞芒萁。杉木 落物反过来对木荷和闽粤栲凋落物有一些抑制作用,而对丝栗栲则有一些促进作用,但这种相互作用未达到显著差异水平。说明杉木与某些伴生植物种类的凋落物在混合分解过程中存在着相互作用的现象,因此,合理保护和恢复林下植物对加快杉木人工林生态系统的养分循环和地力维护具有重要的意义。     

Isolation and functional analysis of a Brassica juncea gene encoding a com-ponent of auxin efflux carrier

Polar auxin transport plays a divergent role in plant growth and developmental processes including root and embryo development, vascular pattern formation and cell elongation. Recently isolated Arabidopsis pin gene family was believed to encode a component of auxin efflux carrier (G(?)lweiler et al, 1998). Based on the Arabidopsis pin1 sequence we have isolated a Brassica juncea cDNA (designated Bjpin1), which encoded a 70-kDa putative auxin efflux carrier. Deduced BjPIN1 shared 65% identities at protein level with AtPINl and was highly homologous to other putative PIN proteins of Arabidopsis (with highest homology to AtPIN3). Hydrophobic analysis showed similar structures between BjPINl and AtPIN proteins. Presence of 6 exons (varying in size between 65 bp and 1229 bp) and 5 introns (sizes between 89 bp and 463 bp) in the genomic fragment was revealed by comparing the genomic and cDNA sequences. Northern blot analysis indicated that Bjpin1 was expressed in most of the tissues tested, with a relatively h     

人轮状病毒NSP4基因变异与功能关系的初步研究

在比较我国人A组轮状病毒一般腹泻患者分离株和重症患者分离株非结构蛋白(NSP)4 cDNA序列时发现,两者在可能与致病性有关的区域(aa131～146)内存在着显著的差异.为进一步探讨这种变异是否与毒力改变有关,利用杆状病毒表达载体在昆虫细胞Sf9中表达两种毒株的NSP4,通过激光扫描共聚焦显微镜初步观察了它对细胞内钙离子浓度的影响.结果表明:两种来源的NSP4均可使细胞内钙离子浓度明显升高,在48h时大致升高3.1～3.4倍,96h时升高5.6～5.8倍,但两种毒株之间的差别并不明显.研究证实,人轮状病毒NSP4与以往报道的动物轮状病毒NSP4一样,可以引起细胞内钙离子增高,即可能与病毒的致病性有关.但重症腹泻毒株SZ1 NSP4第131～146位氨基酸位点出现的变异并未提高其毒力.轮状病毒的毒力改变可能与其它因素有关.     

紫斑牡丹及其一新亚种

本文回顾了有关紫斑牡丹的调查和分类历史。它曾被混同于 P．suffruticosa,P．papaveracea 及P．suffruticosa var．papaveracea。它以叶2至3回羽状复叶,小叶17～33,花瓣白色,基部有大紫斑, 花丝黄色,花盘和柱头淡黄色区别于近缘种。种下分化为两个异域的亚种;秦岭北坡的紫斑牡丹小叶全 部或大部分分裂,是一个新亚种,P．rockii subsp．taibaishanica,而P.rockii subsp．linyanshanii T.Hong et G．L.ostii则是P．rockii subsp．rockii的多余名。     

轮钟花属的恢复及其花粉和种皮证据

光学显微镜和扫描电镜观察表明,金钱豹属(广义)花粉明显分为两个类型:Campanumoea inflata和C.javanica subsp.laponica的花粉5～8沟,外壁具相对密的短刺,刺高不过1μm,而C.lancifolia,C.celebica和C.parviflora的花粉3孔沟,外壁刺稀疏,高于2μm。种子表面纹饰也同样可分为 两类,前两个种一类,其种子表面网状,网眼规则而多角形,直径大于网脊宽度,网脊上的次级纹饰为念 珠状,而后三种为一类,其种子表面网眼不规则,直径与网脊宽度近相等,网脊上的次级纹饰绳索状。可 见花粉特征与种皮性状是高度相关的。后三个种所属的分类群就是被归并了的属Cyclocodon Griffith。 综合花粉、种皮及外部形态,这个属应予恢复。其近缘属应是Platycodon,而不是Campanumoea。     

Immunolcocalization of actin in intact and DNA—and histone—depleted nuclei and chromosomes of allium cepa

The presence of actin in eukaryotic nuclei and chromosomes,and especially in higher plant nuclei and chromosomes,has not been well established.We detected actin in meristematic cells of Allium cepa with indirect immunofluorescence technique and observed bright fluorescence in the intact nuclei and chromosomes,indicating that actin is present in the nuclei and chromosomes of the higher plant.We labeld sections of the meristematic cells of A.cepa with immunogold technique,gold parti cles were concentrated in condensed chromatin and nucleoli,confirming the results of the immunofluoresence observations.We traeated the nuclei and chromosomes of A.cepa with DNase I and 2M NaCl and obtained DNA-and histone-depleted nuclei and chromosomes.Indirect immunofluorescence tests showed that the DNA-and histonedepleted nuclei and chromosomes reacted positively with the anti-actin antibodies.These results demonstrate that the anti-actin antibodies.These results demonstrate that actin exists not only in intact nuclei and chromosomes,but also in DNA-and histone-depleted nuclei and chrmosomes of the plant.In addition,our immuno-fluorescence tests indicate that tropomyosin is present in the nuclei and chromosomes of A.cepa.