蒙桑肌动蛋白基因的克隆与序列测定

为蒙桑基因表达与调控模式的研究以及蒙桑资源的利用提供参考,进行了蒙桑肌动蛋白(actin)基因的克隆与序列测定。结果表明:蒙桑actin基因mRNA序列大小为1 699bp,其中基因编码区1 134bp(GenBank登录号:KF031062),编码的377个氨基酸残基与其他植物的一致性在98%以上。该基因和川桑基因组中其他4个actin基因外显子数量和长度相同,但内含子差异极大,其CDS与桑树Morus010751(EXC30503)的一致性达到98%,氨基酸一致性为100%。聚类分析将其归为Class II类,与来自桑属和毛果杨的actin基因最先聚合在同一分支。     

Topical application of epidermal growth factor accelerates wound healing by myofibroblast proliferation and collagen synthesis in rat

Recombinant human epidermal growth factor (rhEGF) stimulates the proliferation and migration of epithelial cells in human cell culture systems and animal models of partial-thickness skin wounds. This study investigated the effect of a topical rhEGF ointment on the rate of wound healing and skin re-epithelialization in a rat full thickness wound model, and verified whether or not the rhEGF treatment affected both myofibroblast proliferation and collagen synthesis in the dermis. When rhEGF (10 µg/g ointment) was applied topically twice a day for 14 days, there was significantly enhanced wound closure from the 5th to the 12th day compared with the control (ointment base treatment) group. A histological examination at the postoperative 7th day revealed that the rhEGF treatment increased the number of proliferating nuclear antigen immunoreactive cells in the epidermis layer. In addition, the immunoreactive area of alpha-smooth muscle actin and the expression of prolyl 4-hydroxylase were significantly higher than those of the control group. Overall, a topical treatment of rhEGF ointment promotes wound healing by increasing the rate of epidermal proliferation and accelerating the level of wound contraction related to myofibroblast proliferation and collagen deposition.     

HMC-毒素对C型不育玉米根冠细胞原生质体及微丝分布的影响

 用玉米小斑病菌C小种毒素(HMC-毒素)处理C型不育玉米根冠细胞后,采用微丝的特异探针异硫氰酸荧光素-鬼笔环肽进行标记,荧光显微镜下发现HMC-毒素可引起根冠细胞原生质体收缩,并伴有原生质泄漏、原生质体荧光变暗、微丝分布异常等现象。HMC-毒素对根冠细胞的这种影响明显不同于细胞松弛素B (CB);并且与HMC-毒素处理后的同核保持系(N)玉米相比损坏程度要严重得多,N型玉米细胞原生质体只是轻度收缩,仍可见微丝网络分布。根冠细胞对HMC-毒素的这种反应与细胞质的抗病性相关。     

Localization and expression of TGF-β1,2 in fetal and adult skins

AIM:To explore the localization and expression of transforming growth factor-β_1,2 (TGF-β_1,2) and alpha-smooth muscle actin (α-ASMA) in fetal and adult skins. METHODS:Skins of 15 cases of fetuses with different gestational ages and 5 cases of adults were taken, embedded with paraffin wax, and sectioned. Immunohistochemistry method and pathological method were used to detect the expression intensity and distribution of TGF-β_1,2 and α-ASMA. RESULTS: Positive immunohistochemical signals of TGF-β_{1, 2} and α-ASMA were found in fetal and adult skins. In skins derived from young fetus, the positive signals of these three proteins were very weak. Along with the increment in gestational age, the positive cellular rates of TGF-β_1,2M and α-ASMA were elevated progressively. In elder fetal and adult skins, TGF-β_1,2 were mostly distributed in epidermal cells, endothelial cells and some fibroblasts, while α-ASMA was mainly located in myofibroblasts and sweat gland epithelial cells. CONCLUSION:The endogenous TGF-β_1,2might be involved in the cutaneous development at embryonic stage, in the cutaneous structure maintenance at adult stage, and in the wound healing after injury.     

Characterization of spindle cell component of ferret (Mustela putorius furo) adrenal cortical neoplasms – correlation to clinical parameters and prognosis

Adrenal cortical epithelial tumours are common in ferrets. A variant tumour type with prominent spindle cell proliferation has been identified. We characterized these variant tumours with light microscopy and immunohistochemical analysis and correlate these features to clinical parameters and prognosis. We classified 24 ferret adrenal cortical masses with recognizable spindle cell proliferation obtained from the AMC and AFIP databases, based on percentage of spindle cells present and features of malignancy. These masses were separated into hyperplastic nodules and adenomas (both with 1–24% spindle cells), ‘mixed’ adenomas (≥25% spindle cells), adenocarcinomas (1–24%) and ‘mixed’ adenocarcinomas (≥25% spindle cells). Tumours were evaluated immunohistochemically for smooth muscle actin (SMA) and estrogen receptor (ER) expression. Disease‐free interval (DFI) and survival time (ST) were calculated using Kaplan–Meier product limit method. Of 24 cases of spindle cell variant adrenal tumours, one was a hyperplastic nodule, 10 were adenomas, three were ‘mixed’ adenomas, six were adenocarcinomas and four were ‘mixed’ adenocarcinomas. The proliferative spindle cell cytoplasm was SMA‐positive (smooth muscle myocyte origin). ER positivity, seen in nine of 24 cases, was restricted to adenocarcinomas, ‘mixed’ adenomas and ‘mixed’ adenocarcinomas. DFI and ST were significantly reduced in ‘mixed’ adenocarcinomas or tumours with ER expression. DFI was significantly reduced in tumours with marked smooth muscle. The spindle cell component of these variant adrenal tumours is smooth muscle in origin. The presence of abundant smooth muscle, a more malignant histologic grade (‘mixed’ adenocarcinomas) and ER expression are significantly positively correlated to both decreased DFI and decreased ST.     

橡胶树肌动蛋白解聚因子的表达和功能鉴定

为探寻肌动蛋白解聚因子(actin depolymerizing factor,ADF)在调控肌动蛋白解聚和聚合平衡过程中发挥的作用,从橡胶树中获得了Hb ADF基因组序列,经测定,该序列长2 258 bp,含有2个内含子和3个外显子,在裂殖酵母中过表达Hb ADF,获得相对分子质量约38 000的融合蛋白。对裂殖酵母细胞形态进行观察,发现诱导表达Hb ADF的酵母细胞长度显著增加,双核和多核比例达67%。实时荧光定量PCR结果表明,Hb ADF的表达受3%KI处理调控,在橡胶树不同死皮阶段和不同排胶时间段的表达存在变化,说明Hb ADF可能参与了橡胶树排胶和死皮的过程。     

细胞微丝骨架在玉米抗纹枯病菌Rhizoctonia solani 侵染中的作用

为探究细胞微丝骨架在玉米抗纹枯病侵染过程中的作用,采用微丝骨架解聚剂LatB预处理玉米离体叶片后接种立枯丝核菌Rhizoctonia solani AG1-IA,显微观察病原菌的侵染过程,并检测活性氧(ROS)、细胞坏死及抗病基因(PR1、ZmDREB2A)表达等抗病反应情况。结果显示,与未经LatB预处理相比,LatB预处理加快了R.solani侵染后玉米病斑的形成,并影响了侵染结构的发育;在侵染后期,LatB促进了R.solani诱导的玉米叶片中ROS积累、细胞坏死反应和PR1基因表达;溶剂DMSO预处理与未经LatB预处理的结果类似,表明DMSO对本试验的影响较小。研究表明,细胞微丝骨架不仅参与玉米抗R.solani的侵入,而且通过调控ROS、PR1基因表达,细胞死亡等抗病信号提高玉米抗病防御能力。本研究为进一步研究细胞微丝骨架在玉米对纹枯病的抗病机理中的作用提供了重要参考。     

Actin and Myosin Co-Localize in Plasmodesmata and Ectodesmata-Like Structure

Actin and myosin were found to be associated with the cytoplasmic sleeve of plasmodesmata. As cytoskeletal proteins, actin and myosin are believed to regulate the conductivity of plasmodesmata (PDs) in higher plants. Using immunocytochemical methods, we found the two proteins to be co-localized - and closely linked to each other- in plasmodesmata and ectodesmata-like structure in ageing parenchymatous cells of Allium sativum L. We suggest that intercellular communication is affected by the interaction between actin and myosin.     

获能和冻融猪精子间细胞肌动蛋白表达的差异

【目的】分析获能与冻融猪精子细胞肌动蛋白表达的差异。【方法】提取获能和冻融的猪精子蛋白,经过SDS-PAGE分离后,进行Western-blot免疫印迹分析,检测获能与冻融猪精子间细胞肌动蛋白的区别。【结果】新鲜和冻融猪精子细胞肌动蛋白单体的分子质量均约为43ku,但获能猪精子细胞肌动蛋白单体的分子质量约为43和86ku。【结论】冻融的猪精子细胞肌动蛋白单体分子质量约为43ku,但数量有所下降;获能后的猪精子出现了一种新型肌动蛋白亚单位,其分子质量约为86ku。