聚乙烯醇缩甲醛用于游离细胞电镜样品的制作

Susmumu,S.1978年报道用火棉胶膜锥形管固定血细胞的方法。我们用Formvar膜代火棉胶膜,增加了膜的牢固性,具体方法如下: 将配制的2％Formvar氯仿溶液滴5—6滴在彻底冼净的锥形离心管中,把离心管倾斜45°边转动边在洒精灯上微微加热,使其在离心管下半部形成一个Formvar膜的内套,然后加入游离细胞样品1ml,加2.5％戊二(?)     

简易翻拍装置

翻拍机是翻拍文献资料和拍摄实物标本不可缺少的摄影专用设备,笔者在实践中试用了一种简易翻拍装置,该装置结构简单,不需灯光照射,拍摄效果良好,现介绍如下:     

GABA/progesterone-induced polyphosphoinositide (PPI) breakdown and its role in the acrosome reaction of guinea pig spermatozoa in vitro

To investigate whether GABA/progesterone (P4) stimulates PPI breakdown and its role in the acrosome reaction (AR), spermatozoa of guinea pig were preincubated in MCM-LCa2+ for 5.5 h and then labeled with [32P]pi for 1 h. Samples were washed through a three-step gradient Percoll, adjusted to 5×107 cells/mL and exposed to 2 mmol/L Ca2+, 5 mmol/L GABA, 10 mmol/L P4 and other agents. Lipids were separated by t.l.c. and radioactivity in spots determined by scintillation counting. The AR was assessed by phase-contrast microscopy. The results showed that (i) when spermato-zoa were treated with GABA, 32P-label diminished rapidly in phosphatidylinositol 4, 5-bisphosphate (PIP2), phosphatidylinositol 4-phosphate (PIP), and increased in phosphatidic acid (PA). The loss of label from PPI was almost completed by 10 min. The time-course of the AR was much slower than PPI when spermatozoa reached a maximal response by 15 min; (ii) the pattern of PPI hydrolysis and stimulation of AR was similar for the three agonists tested；their potency followed the order A23187＞progesterone≥GABA; (iii) GABA-induced PIP2 hydrolysis and rise in PA and the AR were prevented by inclusion of 10 mmol/L neomycin; (iv) the loss of PIP2 labeling and the increase in PA labeling abolished when spermatozoa were exposed to EGTA or Ca2+ channel blocker. These re-sults indicate that GABA or P4-induced PPI breakdown is an important and essential event in the series of changes to membrane fusion during the AR of guinea pig spermatozoa and this effect is mediated via calcium by activation of phosphatidylinositol-specific phospholipase C.     

GABA/孕酮激发豚鼠精子聚磷酸肌醇降解及其在顶体反应中的作用

为了研究GABA/孕酮(P₄)激发精子聚磷酸肌醇(PPI)降解及其在顶体反应(AR)中的作用,将豚鼠精子在MCM培养基获能培养5.5 h,³²P-标记精子1h,经Percoll密度梯度离心洗涤,然后以AR刺激剂激发精子AR,并对精子膜脂进行提取、分离和鉴定,同时,以相差显微镜评价精子AR%.结果为:(i)GABA刺激二磷酸磷脂酰肌醇(PIP₂)和一磷酸磷脂酰肌醇(PIP)迅速降解,而磷脂酸(PA)增加;在5min时PIP₂和PIP明显下降,10min几近完成,而AR明显滞后,15min才达到峰值;(ii)A23187,P₄和GABA均可激发PPI降解和AR增加,其能力依次为A23187＞P₄≥GABA;(iii)新霉素可明显地抑制Ca²⁺/GABA 或P₄及A23187刺激PIP₂和PIP降解、PA产生和AR增加;(iv)PPI降解需Ca²⁺参与.当EGTA或Ca²⁺通道阻滞剂(La³⁺)存在时,PIP₂和PIP降解,PA产生和AR升高均被明显抑制.上述结果表明,天然激动剂GABA或P₄刺激豚鼠精子膜PPI降解是引起AR的基础,该作用是通过Ca²⁺介导、激活膜磷脂酰肌醇特异磷脂酶C(PIC)而完成的.     

浙江及其邻近地区的紫堇属植物

浙江及其邻近地区有紫堇属(Corydalis Vent.)植物18种、5变种和1变型。本文各并了2变种,订正了1种的名称,发表2个新变种——全叶土元胡和浙江黄堇,并提升1个变种——无距小花黄堇。讨论了小花黄堇、全叶延胡索和台湾黄堇的某些问题。文中附名录和分布表及种子扫描电镜照片10张。     

扫描电镜乙醇冷冻制断器

1980年上海生理所电镜室仿效日本EIKO厂生产的TF-Ⅰ型冷冻割断装置,用钢精锅试制了以DMSO法为主的冷冻割断器,促进了扫描电镜冷冻技术的普及提高。笔者在田中敬一教授乙醇冷冻剖断法原理的基础上,设计并加工制作了简易乙醇冷冻割断器(见图1a)。     

GABA/progesterone-induced polyphosphoinositide (PPI) breakdown and its role in the acrosome reaction of guinea pig spermatozoa in vitro

To investigate whether GABA/progesterone (P4) stimulates PPI breakdown and its role in the acrosome reaction (AR), spermatozoa of guinea pig were preincubated in MCM-LCa2+ for 5.5 h and then labeled with [32P]pi for 1 h. Samples were washed through a three-step gradient Percoll, adjusted to 5×107 cells/mL and exposed to 2 mmol/L Ca2+, 5 μmol/L GABA, 10 μmol/L P4 and other agents. Lipids were separated by t.l.c. and radioactivity in spots determined by scintillation counting. The AR was assessed by phase-contrast microscopy. The results showed that (i) when spermatozoa were treated with GABA, 32P-label diminished rapidly in phosphatidylinositol 4, 5-bisphosphate (PIP2), phosphatidylinositol 4-phosphate (PIP), and increased in phosphatidic acid (PA). The loss of label from PPI was almost completed by 10 min. The time-course of the AR was much slower than PPI when spermatozoa reached a maximal response by 15 min; (ii) the pattern of PPI hydrolysis and stimulation of AR was similar for the three agonists     

如何防止花粉流失

植物花粉肉眼难以看到,在按扫描电镜常规方法制备样品很容易流失。如果在取材时将花药整体采取一起固定,操作时不碰破花药囊,花粉就不会流失。这样可按扫描电镜常规方法处理样品(双固定时间可延长到12小时以上,固定时需抽真空),待临界点干燥做完之后,再用镊子把花药轻轻夹到贴有双面胶纸的样品座上,捣碎花药囊花粉就会从囊中落出而粘在胶纸上,喷金后即可进行电镜观察。注:实验样品由林志华同志供给,蔡继炯同志拍摄电镜照片.