Cutaneous leiomyosarcoma with visceral metastases in a White Carneau pigeon and literature review

Cutaneous leiomyosarcomas are malignant mesenchymal tumors of smooth muscle origin and are reported occasionally in avian species. A 14-y-old male laboratory White Carneau pigeon (Columba livia) was presented for surgical excision of a cervical soft tissue mass. Ultrasonography with color flow Doppler imaging revealed multiple cavitations of mixed echogenicity within the mass and vascularization. Histologically, the dermis and subcutis were expanded by a densely cellular multinodular mass comprised of fusiform cells forming haphazardly arranged broad streams and short interwoven bundles, often surrounding blood vessels and variably sized cavitations. Neoplastic cells were strongly immunopositive for desmin and α–smooth muscle actin, and negative for pancytokeratin, S100, and von Willebrand factor. Based on histopathology and IHC findings, the cutaneous mass was diagnosed as leiomyosarcoma (LMS). The pigeon died 312 d post-operatively. Postmortem examination revealed masses infiltrating the left and right pulmonary airways and one hepatic nodule, but no regrowth at the surgical site. Histologic and IHC evaluation of the pulmonary and hepatic masses were consistent with LMS, representing metastatic foci from the primary cutaneous LMS. Our case highlights the malignant behavior and histomorphologic features of cutaneous LMS in an avian species.     

MSTN基因对牛肌动蛋白细胞骨架调节通路的影响

为探究肌肉生长抑制素（myostatin,MSTN）对牛骨骼肌生长发育的作用机制,本研究前期利用定量蛋白质组学与磷酸化蛋白质组学分析野生型蒙古牛（MG.WT）和MSTN^+/-蒙古牛（MG.MSTN^+/-）腿臀肌肌肉组织中蛋白质水平和磷酸化修饰水平的差异变化,使用已建立的牛骨骼肌卫星细胞体外诱导成肌分化模型,检测设计合成的MSTN siRNA （si-MSTN）干扰效果;采用实时荧光定量PCR和Western blotting方法检测转染si-MSTN的增殖期（GM）和分化第3天（DM3）牛骨骼肌卫星细胞中肌动蛋白细胞骨架调节通路相关基因的mRNA和蛋白水平的表达变化,研究敲低MSTN表达对肌动蛋白细胞骨架调节通路的影响。结果显示,在MSTN^+/-蒙古牛肌肉组织中共鉴定到16个肌动蛋白细胞骨架调节通路相关基因表达丰度上调;转染si-MSTN细胞中的MSTN表达水平极显著降低（P<0.01）;在转染si-MSTN的GM期牛骨骼肌卫星细胞中,肌动蛋白细胞骨架调节通路相关基因ENAH、ACTN4和Cdc42的mRNA水平均显著升高（P<0.05）,PFN1、RhoA和ACTN4的蛋白水平均显著或极显著升高（P<0.05;P<0.01）;在转染si-MSTN的DM3牛骨骼肌卫星细胞中,ENAH、CFL1、SCIN和Cdc42基因mRNA水平均显著升高（P<0.05）,RhoA基因mRNA水平极显著升高（P<0.01）,PFN1和ACTN4的蛋白水平均显著升高（P<0.05）。结果表明,干扰MSTN可以促进肌动蛋白细胞骨架调节通路相关基因的表达,探明了MSTN可能通过介导肌动蛋白细胞骨架调节通路影响牛骨骼肌卫星细胞增殖和成肌分化的分子机制,为进一步研究MSTN对牛成肌分化的调控机制提供参考。     

Dynamics of Actin Polymerization

The process of actin polymerization and depolymerization have some relation with its function,the activation of such process is compatible to its functions. The polymerization progress is divided into four steps: The first step is the activation of the monomer actin. The nucleation of actin nucleus forms in the second step which limits the polymerization speed. The elongation of the F-actin filaments happens in the following step. In the last step, a steady-state is attained, the length of the filament does not change because the polymerizing rate in the barbed end is the same with the depolymerizing rate in the pointed end. Some factors which affect the polymerizing process, such as nucleotide, actin related proteins are discussed. The aim is to know more about how to assemble the complicated system with biomacromolecule and what to function.     

B6-Co与B6小鼠眼睑角质形成细胞的原代无血清培养及比较研究

为进一步研究B6-Co小鼠眼睑发育缺陷机制,首次培养了小鼠眼睑角质形成细胞,并对B6-Co和B6小鼠眼睑角质形成细胞的迁移能力进行划痕实验分析,FITC-phalloidin染色比较B6-Co和B6小鼠肌动蛋白细胞骨架.结果表明,B6-Co小鼠眼睑角质形成细胞迁移的数目和距离明显少于B6小鼠.细胞骨架异常,B6-Co小鼠眼睑闭合不全(EOB)是由小鼠眼睑角质形成细胞迁移缺陷造成的.     

捻转血矛线虫肌动蛋白基因的克隆与表达及其DNA疫苗的构建

根据秀丽新杆线虫等其他几种线虫的肌动蛋白(Actin)开放阅读框(ORF)设计简并引物,以捻转血矛线虫总RNA为模板,合成cDNA,用RT-PCR方法扩增出约为1 100 bp的DNA片段。将该片段克隆到T载体后进行序列测定和分析,结果表明该基因的ORF为1 131 bp,与秀丽新杆线虫、新杆状线虫、肿孔古柏线虫等的同源性高达86%以上,推导出其蛋白质序列含有376个氨基酸,与胎生网尾线虫、秀丽新杆线虫、新杆状线虫、马来丝虫等的肌动蛋白相似性均为98%以上,说明成功克隆了捻转血矛线虫actin基因。将捻转血矛线虫肌动蛋白基因的ORF克隆到pET-28a(+)中,构建了原核表达载体,用IPTG进行诱导表达。SDS-PAGE分析发现,该基因获得了表达,且以包涵体的形式存在,融合蛋白相对分子质量约46×103。以此重组蛋白为抗原,用自然感染捻转血矛线虫山羊血清为第一抗体进行Western blot分析,结果出现1条特异性条带,表明捻转血矛线虫Actin蛋白在自然感染过程中能被宿主的免疫系统识别,可能是一种天然抗原。用纯化重组Actin蛋白免疫小鼠,制备抗血清,以该血清为第一抗体进行Western blot,结果发现该血清能识别捻转血矛线虫成虫蛋白谱中相对分子质量约为42×103的蛋白条带。将捻转血矛线虫actin基因亚克隆到真核表达载体pVAX1中,构建了DNA疫苗pVAX1-ACT,动物免疫试验结果表明该DNA疫苗在机体内获得了表达。     

Segmental axonopathy of Merino sheep in New Zealand

AIM: To investigate an axonopathy of Merino sheep that caused progressive hindlimb ataxia and slight to moderate paresis, with the purpose of understanding its pathogenesis.

METHODS: Tissues were fixed in buffered paraformaldehyde or paraformaldehyde and glutaraldehyde, processed into wax and epoxy resin, respectively, and examined by light and electron microscopy. Fresh frozen spinal cord and trigeminal nerve roots were subjected to homogenisation, centrifugation and two-dimensional electrophoresis. Selected protein spots were identified using matrix-assisted laser desorption ionisation (MALDI) mass spectrometry.

RESULTS. By light microscopy, there were large pale foamy spheroidal axonal swellings affecting peripheral as well as central axons. By electron microscopy, these were shown to contain many membrane-bound vesicles. The main abnormalities in expressed proteins involved cytoskeletal elements and myosin heavy chain, the latter interpreted as associated with the molecular motor myosin Va.

CONCLUSIONS: The disorder is the same as that described in Merinos in Australia as segmental axonopathy, and believed to have an inherited aetiology. The lesions and protein changes indicate abnormalities of the cytoskeleton, its relationship with the myelin sheath, and myosin Va molecular motor. The consequence appears to be abnormal axonal transport and inability to maintain the integrity of axons and their myelin sheaths.     

小麦生理型雄性不育系微丝骨架和胼胝质的变化与其相关基因的表达分析

【目的】研究生理型雄性不育小麦花粉细胞内微丝和胼胝质的结构及其相关基因的表达,并揭示其与生理型雄性不育的关系,为进一步研究化学杂交剂SQ-1诱导小麦生理型雄性不育的机理提供一定的理论依据。【方法】以化学杂交剂SQ-1诱导的生理型雄性不育系ms(A)-西农1376及对应正常可育系(A)-西农1376为试材,用TRITC-phalloidin标记细胞内微丝,苯胺蓝标记胼胝质,qRT-PCR技术分别对肌动蛋白解聚因子TaADF（Actin depolymerizing factor）、类葡聚糖合成酶TaGSL（Glucan synthase-like）进行差异表达分析。【结果】(1)在减数分裂前期Ⅰ、中期Ⅰ、后期Ⅰ这三个时期,生理型雄性不育系花粉细胞的微丝结构与可育系没有显著差异：前期Ⅰ,微丝分布于整个细胞质中,细胞核区域也可见少量微丝环绕细胞核;中期Ⅰ,微丝分布在细胞质中,在形成纺锤体部位染色更深,形成纺锤体微丝,由细胞两极发出的纺锤体微丝伸向赤道板;后期Ⅰ,在向两极移动的染色体的中间部位染色较深,微丝分布较多。(2)在早末期Ⅰ,与可育系相比,不育系花粉细胞没有形成清晰且明显可见的中国灯笼状成膜体微丝结构,且在细胞中线部位亦没有清晰可见的微丝累积。(3)晚末期Ⅰ,可育系花粉细胞在形成细胞板的部位是线性的、平滑的,成膜体微丝消失,而不育系花粉细胞在形成细胞板的部位形成了很大的缝隙,同时,可育系胼胝质在细胞板处的沉积比较平滑,而不育系胼胝质在细胞板处的沉积较可育系相比缺乏,并且是褶皱的、有裂纹的。(4)四分体时期,可育系花粉可见围绕细胞核的辐射状微丝,不育系花粉细胞中微丝呈模糊状态,并且不育系中胼胝质染色的整体荧光强度较可育系减弱。利用实时荧光定量PCR技术分析肌动蛋白解聚因子TaADF和类葡聚糖合成酶TaGSL在减数分裂期的相对表达量,结果发现,不育系中TaADF的相对表达量是可育系的4.28倍,由于TaADF表达量上调,加剧了细胞内微丝解聚,微丝结构受到破坏,同时不育系中TaGSL表达量下降,只有可育系的0.83倍,胼胝质的沉积也受到影响。【结论】TaADF在不育系中上调表达,破坏了细胞内微丝的正常结构,使微丝不能正常行使其功能,进而可能导致花药发育中与育性相关的某些代谢通路等受到影响。与此同时,微丝结构的破坏导致细胞板形成出现异常也可能是引起胼胝质在细胞板处沉积受到影响的一个重要原因。因此,微丝和胼胝质的异常变化与化学杂交剂SQ-1诱导的生理型雄性不育密切相关。     

Thermal stability of carp G-actin monitored by loss of polymerization activity using an extrinsic fluorescent probe

ABSTRACT:   The thermal stability of carp G-actin was investigated by monitoring loss of actin polymerization ability. To determine the amount of native actin remaining after heat treatment, actin was labeled with a fluorescence reagent, N-(1-pyrene)iodoacetamide. The loss of polymerization ability of carp actin during heat treatment, at between 45 and 55°C, occurred faster than that of chicken actin. The inactivation rate was influenced by concentrations of ATP and Ca²⁺ in solution. With the increase of Ca²⁺ concentration, the inactivation of carp actin was markedly suppressed. Furthermore, the activation energy of the inactivation of carp actin obtained from an Arrhenius plot was similar to that of chicken actin. These results indicated that the thermal instability of carp G-actin was due to the low affinites of ATP and Ca²⁺ for carp actin described in a previous report.     

番茄ShARPC5抗白粉病功能分析

【目的】白粉病(powdery mildew)是番茄生产上的重要病害,严重影响番茄的产量。番茄基因组测序工作的完成为抗病基因挖掘提供了重要的信息资源。ARP2/3(actin-related protein 2 and 3)复合体是肌动蛋白微丝骨架动力学的主要调控因子,能够参与包括响应外界胁迫等多种细胞学过程。本研究通过对番茄ARPC5(actin-related protein C5)进行克隆和抗病功能验证,为番茄基因组信息完善、抗病机制解析和分子育种等方面打下基础。【方法】从番茄LA1777(Solanum habrochaites)cDNA中PCR扩增ShARPC5,使用DNAMAN 6.0进行多序列比对;MEGA 6.0构建系统发育树;应用在线工具ProtComp v. 9.0进行亚细胞定位预测。利用实时荧光定量PCR(qRT-PCR)比较接种白粉菌(Oidium neolycopersici,On-Lz)后高感品种Moneymaker(MM)和高抗品种LA1777中番茄ARPC5的表达特征,分析白粉菌侵染与ARPC5表达的相关性。应用病毒诱导的基因沉默(virus-induc...     

蛋白质磷酸化对肌动球蛋白解离及其乙酰化水平的影响

[目的]研究肌球蛋白重链和肌动蛋白磷酸化对其乙酰化水平、肌动球蛋白解离及ATP酶活性的影响,为通过调控磷酸化水平改善肉品嫩度提供理论依据.[方法]以羊背最长肌为材料制备肌肉匀浆液,采用碱性磷酸酶抑制剂(抑制去磷酸化)和蛋白激酶抑制剂(抑制磷酸化)调控其磷酸化水平,在4℃分别孵育0、0.5、4、12、24、48和72 h...