海南省粉褶蕈属的分类研究(Ⅱ)

本文报道了海南省粉褶蕈属[Entoloma(Fr.)Kumm.]的31个种,其中17个为新记录种。并附分种检索表,表中含6个新种。 所有标本保藏于广东省微生物研究所真菌标本室。     

ALTERNATIVE HOSTS OF TRICHOGRAMMA DENDROLIMI MATSUMURA IN DIFFERENT HABITATS (HYMENOPTERA: TRICHOGRAMMATIDAE)

Abstract  This paper deals with alternative hosts of an egg parasitoid. Trichogramma dendrolimi Matsumura in three habitats: mixed forest, pure stand and sparse wood. The experiment was conducted in Liuyan County which is located in the eastern part of Hunan Province. The results suggested that there are 103 species of alternative Lepidopteran hosts for T. dendrolimi . There were two critical periods throughout the year when there were no eggs of Dendrolimus punctatus Walker and few eggs of alternative hosts available for ovipsition by the parasitoids.     

二硫苏糖醇对叶绿体H~＋－ATP酶复合体CF_0的修饰

ＤＴＴ（二流苏糖醇）可解除ＴＰＴ（氯化三苯锡）对叶绿体光合磷酸化的抑制、减弱ＴＰＴ对类囊体跨膜△ｐＨ的抑制和对类囊体腔内质子外流的促进。由于ＴＰＴ较专一作用于ＣＦ０,推测ＣＦ０受ＤＴＴ修饰。这从ＤＴＴ可消除ＴＰＴ对去除ＣＦ１的类囊体残缺膜△ｐＨ的重建和对残缺膜光下收缩的促进得到进一步的证明。ＤＴＴ的作用是还原二硫键成为游离的巯基,因而ＣＦ０可能含有二硫键。从光下ＤＴＴ或暗中ＤＴＴ处理残缺膜对ＴＰＴ作用的影响,可以看到ＤＴＴ对ＣＦ０的修饰是需光的,类囊体膜在光下发生的构象变化,使ＣＦ０的二硫键暴露而被ＤＴＴ修饰。ＣＦ０的二硫键较ＣＦ１γ的二硫键更快、更敏感地被ＤＴＴ所修饰。     

衣藻(Chlamydomonas sp)中间纤维及核纤层存在的证实(简报)

衣藻(Chlamydomonas sp)是属于绿藻门的最低等单细胞植物,为典型的真核生物。迄今以衣藻为材料所作的有关细胞骨架方面的研究多集中在微管蛋白(tubulin)。C.J.Miller等曾以衣藻(Chlamydomonas reinhardtii)全蛋白与几种中间纤维抗体进行免疫印迹实验有阳性反应,但是衣藻中是否存在中间纤维与核纤层是不清楚的问题。衣藻中间纤维与核纤层的形态研究更未见报道。目前认为中间纤维-核纤     

长白落叶松生殖生物学特性研究──Ⅰ．球花芽分化与早期发育

本文研究了长白落叶松（ＬａｒｉｘｏｌｇｅｎｓｉｓＨｅｎｒｙ）大小孢子叶球的分化及其分布规律．获得如下结果：（１）６月下旬芽鳞形成期终止,７月初进入小孢子叶分化期,７月未至８月上旬小孢子叶分化期结束．８月上旬进入小孢子囊分化期,８月下旬出现造孢细胞,９月中旬形成小孢子母细胞．１０月底小孢子母细胞保持在细线期阶段,小孢子叶球进入冬季休眠期．（２）９月初苞片原基开始形成,９月中旬珠鳞原基形成;１０月上旬出现胚珠原始体,１０月下旬大孢子母细胞形成,１０月底大孢子叶球芽进入冬季休眠．（３）小孢子叶球芽主要分布在树冠的中、下部．数量上远远大于大孢子叶球芽的数量,约为大孢子叶球芽的１９倍。大孢子叶球芽主要集中分布在树冠中部,而且树冠下部多于树冠上部。     

细叶黄芪叶肉原生质体发育早期几种细胞器的变化

在细叶黄芪叶肉原生质体发育早期,细胞器的变化较大。离体培养4h后,线粒体的嵴和基质物质开始增加。培养3—5天后,线粒体的数量增加5倍以上,此时可见大部分线粒体围绕细胞核分布。在培养24h后,高尔基体开始发育,它们主要分布在细胞质周边区域。多糖细胞化学染色表明,高尔基体内沉积着大量嗜银物质。培养1天后,粗面内质网开始发育。培养3天时,部分叶绿体边缘出现一些空隙结构。随着叶绿体内膜结构的消失,淀粉粒增大,叶绿体逐渐转变为造粉质体。     

抗氧化剂对苜蓿原生质体早期培养的影响

研究发现,分离原生质体的酶解脱壁处理可以诱导苜蓿细胞产生活性氧。培养基中添加抗氧化剂,有助于提高培养原生质体的分裂频率,缓解褐化现象的出现。经紫外照射处理的培养基不利于苜蓿原生质体的生长和分裂,添加抗氧化剂后,紫外辐射所引起的不良效应则被抵消。因而,通过抗氧化剂对活性氧的清除,有助于早期原生质体的培养。     

用原位分子杂交技术定位牛生长激素基因于5号染色体

本工作利用放射性标记的ｂＧＨ基因（３．０ｋｂ）为探针,通过原位杂交定位牛生长激素基因于染色体５ｑ２２－２６内。该结果与以前的ｂＧＨ基因定位的结果不同,讨论了基因探针、基因定位方法等方面与定位准确性的关系。     

分泌载体pUS186的构建及地衣杆菌α－淀粉酶基因在枯草杆菌中的表达和分泌

利用枯草杆菌的分泌系统构建分泌型表达载体表达和分泌外源基因产物具有重要的商业价值。我们用鸟枪法克隆了枯草杆菌染色体的启动子和信号肽序列,将克隆的序列连接到能在枯草杆菌中复制的质粒ｐＵＢ１８上,获得分泌型表达载体ｐＵＳ１８６。为了测试构建的载体ｐＵＳ１８６的功能,将地衣杆菌α－淀粉酶基因的缺失了启动子和信号肽序列的片段重组进该质粒,经过Ｂａｌ３１酶切,Ｔ４ＤＮＡ聚合酶补齐等处理,获得ｐＵＳＡ１８６Ⅱ及ｐＵＳＡ１８６Ⅰ系列质粒,将这些重组质粒转化枯草杆菌ＱＢ１１３０（ａｍｙ－）后都能向胞外分泌淀粉酶,酶活测定结果表明,基因表达水平比用原有的启动子高１－２倍,蛋白质分泌率在８４－９６％之间。     

Regulation of vasoactive intestinal peptide expression in sympathetic neurons in culture and after axotomy: The role of cholinergic differentiation factor/leukemia inhibitory factor

Vasoactive intestinal peptide (VIP) expression increases in sympathetic neurons when they are grown in dissociated cell or explant cultures and when they are axotomized in vivo. In dissociated cell culture, the magnitude of the VIP increase was reduced when nonneuronal cells were removed and medium conditioned by ganglionic nonneuronal cells increased VIP in neuron-enriched cultures. Antiserum Against cholinergic differentiation factor (also leukemia inhibitory factor; CDF/LIF), but not against ciliary neurotrophic factor, immunoprecipitated this activity. Medium conditioned by sympathetic ganglion explants also contained a VIP-stimulatory molecule that was immunoprecipitated by CDF/LIF antiserum, and CDF/LIF antiserum partially blocked VIP induction in explants. CDF/LIF mRNA was increased in dissociated cell cultures, in ganglion explants and in vivo after axotomy. Our results suggest that CDF/LIF released from ganglionic nonneuronal cells plays an important role in regulating VIP after axotomy. 1994 John Wiley & Sons, Inc.