Mitotic arrest by deuterium oxide

In marine invertebrate eggs, where cell divisions occur without growth, deuterium oxide produces arrest of, or serious delay in, mitosis and cytokinesis. All stages requiring assembly or operation of mechanical structures in the cytoplasm are sensitive to D.O. The block is reversible in some cells.     

Blockade of deoxyribonucleic acid synthesis by deuterium oxide

Interference with deoxyribonucleic acid replication need not be a primary mechanism in the blockade of cell division by deuterium oxide, but current hypotheses on the molecular basis of the blockade do suggest that such interference might take place under appropriate conditions. Autoradiographic experiments support the suggestion, for whereas normal sea urchin eggs incorporate H(3)-thymidine into deoxyribonucleic acid from almost the beginning of development, cells immersed in deuterium-enriched media do not. Blockade of mitosis and inhibition of thymidine incorporation are simultaneously relieved when the eggs are returned to normal water.     

Production of urinary bladder carcinomas in mice by sodium saccharin

Pellets weighing 20 to 24 milligrams and containing 20 percent sodium saccharin suspended in cholesterol were surgically implanted into the urinary bladder lumens of female Swiss mice (60 to 90 days old) under ether anesthesia. Incidences of mouse bladder carcinomas in animals exposed to these pellets were 47 and 52 percent as compared with incidences of 13 and 12 percent in control mice exposed to pellets of pure cholesterol. The exposure of the mouse bladder to saccharin was very brief, because the time required for 50 percent of the compound to be eluted from the pellets was about 5.5 hours.     

Dynamic structure of membranes by deuterium NMR

Progress in our understanding of the dynamic structure of membrane lipids and proteins has recently been made possible by the advent of high-field "solid-state" nuclear magnetic resonance spectroscopic studies of specifically deuterium-labeled systems. Major features of lipid and protein dynamics have been deduced.     

Circadian activity rhythm of the deer mouse, Peromyscus: effect of deuterium oxide

Chemical modification of a vertebrate activity rhythm, the circadian (approximately 24-hour) rhythm of Peromyscus leucopus noveboracensis, has been demonstrated. Activity in a running wheel was used to measure the rhythms of mice kept individually in conditions of continuous darkness. Deuterium oxide was presented in the drinking water. The length of the periods of rhythm increased directly and linearly with the increase in concentration of deuterium oxide. There is no threshold for this effect, and the maximum concentration of deuterium oxide (30 percent) that was presented resulted in a 6 percent lengthening of the period of circadian rhythm. The mice reverted to rhythms similar in period length to control values after deuterium oxide was withdrawn from their drinking water.     

棉花雄性不育材料的组织培养初探

利用组织培养方法繁殖棉花不育系。通过优化培养基组合程序研究,对污染较严重的棉花不育系单株材料,先用70%酒精浸泡10~15 s,倒出后马上用无菌水冲洗,加入0.1%升汞灭菌8 min,用无菌水冲洗5~6次。愈伤组织诱导培养基诱导效果最佳的是MSB 2,4-D 0.1 mg/L IAA 0.1 mg/L KT 0.1 mg/L,最适合愈伤组织分化的培养基为MSB IAA 0.1 mg/L 2-IP 3.0 mg/L CM 100 ml/L AC 2.5 g/L。     

Male sterility induced in tomato by sodium 2, 3-dichloroisobutyrate

Increasing the pH from 3.0 to 10.8 increased the uterine weight three-fold and the number of positive vaginal smears from 0 to 78 percent in immature rats injected with chorionic gonadotropin in aqueous solution. Activity of a solution held at pH 2.6 and 5 degrees C for 24 hours was restored by neutralization.     

青花菜雄性不育系组培快繁技术研究

青花菜原产意大利,近几年在欧美各国及日本等发达国家迅速发展,中国引种较迟,大规模栽培种植的时间很短,但发展迅猛。由于中国90％左右的种子都是从国外引进,价格昂贵,且大部分为雄性不育,留种困难,给中国青花菜的生产带来了一定困难[1]。采用组织培养的方法保存不育株在育种上具有重要的应用价值。Anderson等[2]最早采用青花菜花芽建立雄性不育系快繁技术体系,用青花菜花蕾、花器官、叶片[3-4]、带柄子叶[5]及腋芽[6]作外植体进行组织培养研究均有过报道。本试验以国外引进的不育系杂交种植株上的腋芽和无菌苗的茎尖为外植体进行快繁研究,以期为青花菜繁殖及应用提供有效途径。     

Production of immunoglobulin isotypes by Ly-1+ B cells in viable motheaten and normal mice

Almost all B cells in autoimmune mice with the viable motheaten (mev) mutation express the Ly-1 cell surface antigen, which marks a minor population of B cells constituting a separate lineage in normal mice. Immunoglobulins primarily of the M and G3 classes, which in both normal and mev mice contain high levels of lambda light chain, are produced in excess in mev mice. These and other observations suggest that the development of B cells that express Ly-1 is regulated independently from the development of B cells that do not express Ly-1. B cells bearing the Ly-1 surface antigen may play specialized roles in the normal immune system and in autoimmunity by regulating other B cells via lymphokines, by producing antibodies to self and certain foreign antigens, and by preferentially secreting immunoglobulin M and immunoglobulin G3.     

慢病毒活体介导精原干细胞生产转基因小鼠

【目的】用慢病毒在体内感染精原干细胞,建立转基因动物生产技术平台。【方法】用三质粒慢病毒载体系统转染293T细胞包装慢病毒,转染后裂解细胞,收集携带绿色荧光蛋白(EGFP)基因的慢病毒。将慢病毒液注射到小鼠曲细精管,获得F0代小鼠,制备小鼠睾丸组织切片,进行免疫双荧光检测。将F0代小鼠与野生型母鼠交配,获得F1代小鼠,PCR检测F1代是否为转基因小鼠。【结果】通过裂解细胞的方法成功制得慢病毒,将其注射到小鼠曲细精管,获得了10只F0代小鼠,经免疫双荧光检测,发现慢病毒可在活体上感染精原干细胞。8只F0代小鼠与野生型母鼠交配后共获得了41只F1代小鼠,经PCR检测,21只携带慢病毒基因片段,转基成功率为51.22%,表明慢病毒介导的基因改造是可遗传的。【结论】建立了一种操作简单、花费少、易于实施的慢病毒活体介导精原干细胞生产转基因小鼠的技术体系,该技术也可以推广到其他动物上,对于加速功能基因鉴定、疾病模型构建和家畜转基因育种等领域的研究有促进作用。     

GENESIS诱导小麦雄性不育的形态学和细胞学观察

从形态学和细胞学方面,观察了GENESIS诱导小麦雄性不育的过程.结果表明,喷药处理后,抽穗后穗部为浅绿色,小穗排列松散,麦穗呈"爆裂状"且透亮,雄蕊退化;Feek'sstage8.0时期喷施,大部分表现为无花粉型,药室内花粉母细胞解体,只留下空腔;Feek'sstage9.0时期喷施大多为花粉败育型,败育花粉中大都只发育到单核期,部分发育到二核期,小孢子畸形,细胞核解体,细胞质稀薄,也发现有多核花粉粒存在;喷施时期越早,败育得越彻底,在3kg·hm-2剂量处理下,败育发生较为彻底,而且对花粉囊壁影响较小.     

C-type cytoplasmic male sterility in corn

It is shown experimentally that late break of anthers in C-type CMS corn is controlled by modifier genes, probably of complementary action, localized in the cytoplasm of the maternal line as well.     

Radio-wave heating of iron oxide nanoparticles can regulate plasma glucose in mice

Medical applications of nanotechnology typically focus on drug delivery and biosensors. Here, we combine nanotechnology and bioengineering to demonstrate that nanoparticles can be used to remotely regulate protein production in vivo. We decorated a modified temperature-sensitive channel, TRPV1, with antibody-coated iron oxide nanoparticles that are heated in a low-frequency magnetic field. When local temperature rises, TRPV1 gates calcium to stimulate synthesis and release of bioengineered insulin driven by a Ca(2+)-sensitive promoter. Studying tumor xenografts expressing the bioengineered insulin gene, we show that exposure to radio waves stimulates insulin release from the tumors and lowers blood glucose in mice. We further show that cells can be engineered to synthesize genetically encoded ferritin nanoparticles and inducibly release insulin. These approaches provide a platform for using nanotechnology to activate cells.     

3种新型化学杂交剂诱导小麦雄性不育效果比较

以杂种小麦新品种西杂一号和 1 6个小麦常规品种为供试材料 ,应用混合线形模型研究了 3种化学杂交剂 SQ- 1 ,GENESIS和 BAU94 0 3诱导小麦雄性不育的效果及对种子性状的影响。结果表明 ,SQ- 1在 3种化学杂交剂中的杀雄效果最好 ,并对杂交种种子的千粒重有提高作用 ;GENESIS和 BAU94 0 3不同程度对杂交种种子千粒重有降低作用 ,其中 BAU94 0 3影响更大 ;SQ- 1和 GENESIS对杂交种发芽率、发芽势和容重的影响与对照不喷药无显著差异 ,但 BAU94 0 3与对照有显著差异     

GENESIS诱导小麦雄性不育与幼穗中乙烯含量的关系

在小麦发育的 Feekes8.5时期用化学杂交剂 GENESIS进行处理 ,分别在小麦花药发育的单核期、二核期和三核期测定幼穗中乙烯释放量的变化 ,研究 GENESIS诱导小麦雄性不育与乙烯的关系。结果表明 :经化学杂交剂 GENESIS诱导后 ,幼穗中乙烯释放量在 3个时期均明显高于对照。随着 GENESIS喷施剂量的增加 ,诱导小麦雄性不育率也相应增加 ,同时幼穗中乙烯释放量也表现出相同的增长趋势。表明 GENESIS诱导小麦雄性不育的生化机理在于 GENESIS诱导小麦幼穗中乙烯释放量增加 ,乙烯释放量的变化与小麦雄性不育有直接关系。同时 ,利用乙烯合成抑制剂 (AVG)处理细胞核质互作雄性不育系后 ,内源乙烯释放速率降低 ,育性得到部分恢复     

红莲型细胞质雄性不育水稻线粒体atp6基因转录本的编辑位点研究

\t\t\t\t\t目的\t\t\t\t\t探讨亚洲栽培稻CMS基因起源及水稻线粒体atp6特异性引物作为稻属DNA条形码标记的应用。\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t方法\t\t\t\t\t用水稻atp6特异性引物通过PCR检测产于中国的4种水稻,共720个个体,并对111个个体测序。\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t结果\t\t\t\t\t普通野生稻和亚洲栽培稻中均检测到atp6保守序列。药用野生稻中没检测到扩增产物。疣粒野生稻中检测到的5个单倍型间共计17个变异位点。澜沧、普洱、勐海居群共同拥有H1,单倍型H2、H3、H4和H5分别为新平、墨江、保亭和崖城居群特有。云南组和海南组,组内平均遗传距离为0,组间为0.02;组间遗传分化系数F_st为92.08%;变异位点数(S)、单倍型数(h)、核苷酸多样性(P_i)均显示：云南组(4、3、0.002 01)遗传多样性大于海南组(1、2、0.001 31);云南组单倍型多样性H_d为0.6,海南组为1。5个单倍型与水稻atp6保守序列的相似度最高为45.19%。最大似然法ML进化树显示：澜沧、普洱及勐海一带可能是疣粒野生稻的起源地,海南疣粒野生稻可能源自大陆。\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t结论\t\t\t\t\t水稻atp6特异性引物可作为疣粒野生稻种内条形码标记,该标记也可区分普通野生稻、药用野生稻和疣粒野生稻。从线粒体DNA角度证实亚洲栽培稻CMS基因源自普通野生稻。\t\t\t\t\t\t\t\t\t     

化学杂交剂SQ－1诱导小麦雄性不育及与不同小麦品种互作效应的研究

以 18个小麦品种和不同剂量化学杂交剂 SQ- 1为处理 ,研究了 SQ- 1的杀雄效果及不同基因型小麦对 SQ- 1反应的遗传差异。结果表明 ,在适宜的 SQ- 1喷施剂量与时期下 ,供试品种均能被诱导产生大于95 %的雄性不育率。对参试品种而言 ,适宜时期为 Feekes8.0 - Feekes8.5 ,适宜剂量为 3.0～ 5 .0 kg/ hm2 ,以5 .0 kg/ hm2 效果最好。 SQ- 1与不同基因型小麦品种不存在明显的互作效应。