大白菜游离小孢子培养胚胎发生中的加倍机制

 利用Leica体视显微镜, DAPI荧光染色观察比较大白菜小孢子正常发育为成熟花粉粒与游离小孢子培养胚胎发生细胞核的分裂方式, 探讨大白菜游离小孢子培养胚胎发生及其自然加倍的机理。观察结果显示以B途径为主要发育途径的大白菜小孢子, 胚胎发生的启动机制是热激诱导下单倍体小孢子体积膨大, 染色体发生自然加倍, 从而激发小孢子进入孢子体发育途径; 大白菜小孢子胚再生植株具有较高的自然加倍率, 这与小孢子培养热激诱导激发小孢子单核自然加倍为二倍体密切相关。     

栉孔扇贝人工雌核发育的细胞学观察

运用荧光显微镜观察了栉孔扇贝正常卵子与雌核发育卵子在受精和成熟分裂过程中的核相变化。结果表明,尽管紫外线照射没有影响受精卵的成熟分裂以及雌性、雄性原核的形成,但使雌核卵的发育速度出现明显的滞缓。在第1次卵裂中期,雌核发育卵子中的雄性原核没有像雌性原核那样形成染色体,而是浓缩为一染色质小体(DCB),游离在细胞质中,不参与核分裂。胞质分裂结束时,DCB位于2个卵裂球之一的细胞质内或在赤道板处被分割成两部分。实验结果首次提供了栉孔扇贝雌核发育的细胞学证据。     

烟草雄性核在花粉管萌发伸长过程中的形态变化

尝试把荧光染料ＤＡＰＩ配入花粉萌发液作为活体观察的指示剂，在荧光显微镜下对花粉萌发花粉管及伸长时雄性核的动态变化过程作光学水平的连续追踪，观察到：①烟草花粉在含ＤＡＲＩ染料的蔗糖萌发液中能够正常萌发伸长花粉管；②在花粉管生长延伸过程中，营养核与生殖核的移动是一个有联系的过程；联系方式常见为营养核围裹生殖核，两者紧贴和两核之间有细丝相联几种情况；③生殖核与营养核在花粉粒和花粉管中移动时，其形态均发生变化，以营养核尤为剧烈。表现为核物质从凝集状态向弥漫状态转变，最终复归为凝集状态；④营养核一般居前，但也有相当数量的生殖细胞居前的现象；⑤由于原生质团从花粉粒中涌入花粉管，推动了生殖核与营养核的前移运动。     

Steedman’s wax包埋切片DAPI染色法证实铝诱导花生根尖细胞程序性死亡

【目的】检验Steedman’swax包埋切片DAPI染色法是否适用于观察花生根尖细胞核形态。【方法】分别采取100μmol/L AlCl3处理不同时间（0、4、8、12 h）后两个花生品种（铝敏感型中花2号和耐铝型99-1507）的根尖,经过Steedman’s wax包埋切片等一系列过程,利用荧光染料DAPI染色观察细胞核形态变化。【结果】100μmol/L AlCl3可引起花生根尖细胞核形态发生改变,核质浓缩、核边缘化、呈新月状等,具有明显的PCD特征。花生根尖细胞在铝胁迫下发生PCD,PCD程度与花生耐铝性呈负相关,与处理时间呈正相关。【结论】Steedman’swax包埋切片DAPI染色法是一种快速、高效的适用于观察花生根尖细胞核形态的方法。     

High tolerance of European plum varieties to plum leptonecrosis

A 13 year comparative study was carried out on the behaviour of four European and two Japanese plum varieties grown in adjacent rows in an area of northern Italy where plum leptonecrosis is epidemic. Within seven years, 100% of the Japanese plum trees became symptomatically infected. Nine years after planting, five trees of each of the European cvs, which were asymptomatic, were top-grafted with healthy buds of the cv Ozark Premier, which is an indicator for plum leptonecrosis. Based on the results of PCR analysis, DAPI staining and on the reaction of the top-grafted Ozark Premier indicators, 50% of the European plum trees, despite their healthy appearance, were shown to be infected with plum leptonecrosis. The detectable presence and graft transmissibility of the plum leptonecrosis phytoplasma in the asymptomatic European plum trees means that the European plum trees are not resistant to the infection but that they are tolerant. The active presence of a still unknown vector/s in the investigated area is stressed as well as the important role of Prunus domestica L. played in the conservation and spread of plum leptonecrosis.     

应用生物学软件分析四季橘染色体核型和带型

【目的】为了改进以往人工方式观测染色体精准度的不足,【方法】采用MicroMeasure软件和Image-Pro Plus图像分析软件对4,6-联脒-2-苯基吲哚(DAPI)荧光染色的四季橘(Citrus madurensis Lour.Tseng)体细胞中期染色体分别进行核型分析和三维重建。【结果】得到四季橘的核型公式2n=18=16 m(2SAT)+2 sm,其核型类型为1B型,属于进化中较原始类型;获得四季橘染色体立体图,并依据每条前中期染色体(从短臂到长臂)DAPI荧光强度变化,构建出染色体带型模式图。【结论】该研究利用染色体图像分析软件对染色体进行识别,获得了较丰富的染色体核型数据信息,为柑橘细胞遗传学研究提供了新方法。     

大鳞副泥鳅(2n♀)×泥鳅(4n♂)杂种后代染色体带型及FISH分析

文章对二倍体大鳞副泥鳅♀×四倍体泥鳅♂杂交后代的染色体进行Ag-NORs、CMA3/DA/DAPI及FISH等系列研究.结果表明,①在对照组泥鳅×泥鳅(2n×2n)杂交后代的间期核和中期分裂相中最高银染点数为2个,杂交组2n×4n杂种后代的间期核和中期分裂相中最高银染点数为3个;②在对照组2n×2n杂交后代有丝分裂中期...     

Mycoplasma hyopneumoniae-derived lipid-associated membrane proteins induce apoptosis in porcine alveolar macrophage via increasing nitric oxide production,oxidative stress,and caspase-3 activation

Mycoplasma hyopneumoniae is the primary etiological agent of enzootic pneumonia in swine. Lipid-associated membrane proteins (LAMP) of mycoplasma are the main pathogenicity factors in mycoplasma diseases. In this study, we investigated the effects of M. hyopneumoniae LAMP on porcine alveolar macrophage (PAM) 3D4/21 cell line. Apoptotic features, such as chromatin condensation and apoptotic bodies, were observed in LAMP-treated PAM 3D4/21 cells. Moreover, LAMP significantly increased the number of TUNEL positive apoptotic cells in PAM 3D4/21 cells compared with the untreated control. In addition, flow cytometric analysis using dual staining with annexin-V-FITC and propidium iodide (PI) showed that LAMP of M. hyopneumoniae induced a time-dependent apoptosis in PAM 3D4/21 cells. Moreover, increased levels of superoxide anion production and activated caspase-3 in PAM 3D4/21 cells were observed after exposure to LAMP. Increased production of nitric oxide (NO) was also confirmed in the cell supernatants. Besides, apoptotic rates increase and caspase-3 activation were suppressed by NOS inhibitor or antioxidant. It is suggested that LAMP of M. hyopneumoniae induced apoptosis in porcine alveolar macrophage via NO production, superoxide anion production, and caspase-3 activation.     

利用荧光原位杂交技术分析新合成异源四倍体拟南芥

在植物异源倍化育种中或者通过异源多倍化导入有利基因时,初级杂交后代异源多倍体减数分裂期间,避免部分同源染色体干扰,使同源染色体正常联会和配对以及正确分离是产生功能性雌雄配子的细胞学基础。本研究通过种间杂交技术,获得初级杂交后代异源四倍体拟南芥A. suecica,并重点分析其花粉母细胞减数分裂期同源染色体联会和配对情况。利用DAPI技术染色证明了花粉母细胞减数分裂期间核内染色体数目的正确性和均等分裂;而用荧光原位杂交技术进一步证明了核内染色体组的来源的正确性和同源染色体联会和配对的精准性。该结果证实新合成异源多倍体能进行正常的减数分裂和产生功能性雌雄配子,为种属间杂交和异源多倍体育种以及植物杂种优势利用提供了有利的细胞遗传学证据。