Introduction of human DNA into mouse eggs by injection of dissected chromosome fragments

A procedure has been developed for introducing exogenous DNA into mouse eggs by injection of chromosome fragments. Chromosome fragments were dissected from human metaphase spreads and microinjected into the pronuclei of fertilized mouse eggs. Many of the injected eggs subsequently exhibited normal pre- and postimplantation development. Embryos obtained from eggs injected with centromeric fragments retained human centromeric DNA as demonstrated by in situ hybridization analysis. From eggs injected with noncentromeric fragments, a mouse was obtained whose tail tissue exhibited the presence of human DNA. This procedure should facilitate incorporation of very large (more than 10 megabases) DNA fragments into cells and embryos without the need for cloned sequences.     

胚胎注射谷氨酰胺对肉仔鸡早期小肠发育的影响

选用已孵化18 d的肉仔鸡活胚蛋240枚,随机分成4组,每组6个重复,每重复10枚蛋。Ⅰ组注射1 mL 7.5 mg/mL生理盐水作为对照,Ⅱ、Ⅲ、Ⅳ组分别向鸡胚羊膜腔内注射质量浓度为5、10、15 mg/mL的谷氨酰胺营养液1 mL。结果表明:注射谷氨酰胺能不同程度提高肉仔鸡早期小肠绒毛高度,降低隐窝深度,提高绒毛高度与隐窝深度的比值,但作用效果因观察时段、肠段及营养液质量浓度的不同而有所差异。     

Continuous gas chromatography

Continuous gas chromatography has been achieved with a radialflow chromatographic channel free of packing and formed between two closely spaced (50 to 75 microns) disc surfaces (optically flat and solvent-coated) rotating at one-half or one revolution per second. This technique provides high capacity and immediate response (in a fraction of a second). Mixtures of hydrocarbon gases have been separated at flow rates of 6 to 30 cubic centimeters per minute with 100 to 150 cubic centimeters per minute of nitrogen carrier gas in a chromatographic channel only 39 millimeters long.     

Increased litter size in the rat x-irradiated during the estrous cycle before mating

Average numbers of ovulations, implantations, and living fetuses obtained from rats x-irradiated during the estrous cycle before mating are a function of both the radiation dose and the time of exposure during the cycle. Animals irradiated during metestrus or the day thereafter exhibit significant increases in the factors studied, while those irradiated on the 3rd day after metestrus maintain fewer implantations after exposure to 300, 500, and 600 roentgens, and fewer living fetuses after exposure to 100 to 600 roentgens.     

澄湖似刺鳊鮈个体繁殖力的研究

对澄湖48尾产卵前成熟似刺鳊鮈雌鱼的个体绝对繁殖力(F)、体长相对繁殖力(F_L)和体重相对繁殖力(F_W)分布特征、变化规律及与体型若干形态学指标的关系进行了研究。结果显示,似刺鳊鮈样本由1~5龄鱼组成,F主要变幅在1.71×10⁴~3.83×10⁴粒之间(平均为2.45×10⁴粒);F_L主要变幅在0.94×10³~1.52×10³粒/cm之间(平均为1.13×10³粒/cm);FW主要变幅在95~155粒/g之间(平均为119粒/g)。F与体长、体重和年龄分别呈二次函数、直线和三次函数相关,F_L与体长、体重均呈三次函数关系,F_W与它们相关不显著。综合分析,在进行渔业生产时以体长21~23 cm、年龄2~3龄鱼为人工催产亲本为宜。采用SPSS软件的曲线回归分析其F和F_L均与体长、体重和成熟系数密切相关,而F_W仅与成熟系数相关,在实际中可直接用体长、体重同繁殖力的关系来预测似刺鳊鮈的绝对繁殖力。     

Deoxyribonucleic acid in germinal vesicles of oocytes of Rana pipiens

The amount of DNA isolated from germinal vesicles of Rana pipiens oocytes is similar to that isolated from whole unfertilized eggs, and this suggests that oocyte nuclei are the source ofmuch of the DNA obtained from whole eggs. Fluorometric determinations of the isolated DNA show the presence of 0.004 microgram of DNA equivalents per germinal vesicle. Similar values were obtained by estimations from comparisons of the cesium chloride densitygradient profiles of sample DNA and a known amount of reference DNA from Pseudomonas aeruginosa. The buoyant density of DNA prepared from isolated germinal vesicles is the same as that of frog-liver DNA, 1.706 grams per cubic centimeter, as determined by equilibrium sedimentation in a cesium chloride density gradient.     

Requirement of CD9 on the egg plasma membrane for fertilization

CD9 is an integral membrane protein associated with integrins and other membrane proteins. Mice lacking CD9 were produced by homologous recombination. Both male and female CD9-/- mice were born healthy and grew normally. However, the litter size from CD9-/- females was less than 2% of that of the wild type. In vitro fertilization experiments indicated that the cause of this infertility was due to the failure of sperm-egg fusion. When sperm were injected into oocytes with assisted microfertilization techniques, however, the fertilized eggs developed to term. These results indicate that CD9 has a crucial role in sperm-egg fusion.     

Induction of choline phosphotransferase and lecithin synthesis in the fetal lung by corticosteroids

Rabbit fetuses 23 to 24 days of gestation were injected with either 9-fluoroprednisolone acetate or saline. Three days later the lungs of steroid-treated animals showed a significant increase in lecithin concentration and cholinephosphotransferase activity. In addition, lung slices from these animals incorporated more [(14)C]choline into lecithin. The rise in enzyme activity and [(14)C]choline incorporation was blocked by prior treatment of fetuses with cycloheximide but not by treatment with actinomycin D. It is proposed that the corticosteroids induce de novo synthesis of the lung enzyme, which in turn leads to increased synthesis of lecithin through the choline incorporation pathway. Furthermore, it appears that the site of regulation involves translation of messenger RNA.     

小鼠受精卵在体内外发育成桑椹胚的对比研究

用１０单位孕马血清和１０单位人绒毛膜促性腺素使小白鼠超数排卵,自然交配后分两组,一组取受精卵,统计受精卵个数,并在ＣＺＢ培养基微滴内培养７８ｈ,统计发育成又桑椹胚的个数。另一组,让受精卵在体内自然发育７２ｈ,收集桑椹胚,统计其个数。比较研究受精卵在体内外发育到桑椹胚的能力。实验结果表明,每只鼠的平均冲出受精卵数为２８．２枚;受精诳在体外培养时桑椹胚的发育率为８８％;因此在体外培养时从每只鼠平均可得     

Serum protein synthesis by the fetal rat

Injection of C(14)-labeled amino acids intraperitoneally into rat fetuses in utero results in greater labeling of fetal serum proteins than when the amino acid is injected into the mother. Maternal partial hepatectomy leads to only minimal changes in serum protein synthesis. Rat fetuses synthesize at least some of their serum proteins during the last 3 days of gestation.     

禽流感高免卵黄抗体的研制与应用

用禽流感Ｈ９亚型油乳剂灭活苗多次免疫产蛋鸡,获得高免蛋,并禽流感高免卵黄液,在发病初期给禽流感病鸡肌注高免卵黄液,获得了满意的治疗效果。     

细胸金针虫(Agriotes fuscicollis Miwa)的饲养方法及其生活史观察

本文对细胸金针虫的饲养方法作了系统的报道.在蛹、成虫和卵的饲养中,成活率均高,方法简便且易于观察;虽然幼虫自相残食和饲养期间遭受微生物侵袭,死亡率偏高,但仍得出预期的饲养结果.经1981—1987年室内饲养和田间观察得知,该虫有世代上的多态现象(Polymorphism),在武威、民勤一带3年1代,亦有2年或4—5年1代者.主要以幼虫越冬,幼虫期平均958.5天,蛹期平均15天,当代成虫寿命30—68天,少数越冬成虫270天左右,卵期平均14天.     

Vascular smooth muscle: quantitation of cell thickness in the wall of arterioles in the living animal in situ

The wall of microarterial vessels, in the living animal in situ, was examined at magnification up to x 6500 on the television screen. The optical resolution af the cell components of the wall was sufficiently clear to permit image formation and splitting for permanent recording and quantitation. Thickness of single smooth muscle cells at rest was estimated to be 2.08 microns (S.D. +/- 0.24 micron) and 2.78 microns (S.D. +/- 0.59 micron) by two different approaches. Changes in cell thickness during activity were also recorded and quantitated.     

沙塘鳢室内繁殖研究

[目的]探索沙塘鳢繁育技术,为规模化养殖提供基础。[方法]采用了人工繁殖和自然繁殖两种方法对沙塘鳢天然捕捞成熟个体进行室内繁殖研究。人工繁殖分别用催产剂HCG、催产合剂LRH-A2＋DOM催产亲本;自然繁殖选择性腺成熟雌雄鱼按1.0∶1.2比例放入塑料箱中交配产卵,定期收集卵粒、统计产卵雌鱼数。[结果]注射HCG人工催产沙塘鳢雌鱼易发生流产现象,获得的受精卵在卵巢中分散粘附,孵化第2天卵粒开始发白、脱落,未孵化出鱼苗;催产合剂LRH-A2＋DOM催产亲本未获得受精卵。自然繁殖组中沙塘鳢自然产卵率70%,受精卵在鱼巢上粘附规则,经孵化获得鱼苗,孵化率50%。[结论]沙塘鳢宜采取自然繁殖方式进行繁殖。     

Congenital malformations induced by mescaline, lysergic acid diethylamide, and bromolysergic acid in the hamster

Malformations of the brain, spinal cord, liver, and other viscera; body edema; and localized hemorrhages were found in fetal hamsters from mothers injected subcutaneously with a single dose of mescaline, lysergic acid diethylamide, or 2-bromo-D lysergic acid diethylamide on the 8th day of pregnancy. In addition, all three drugs produced an increase in the percentages of small fetuses per litter, of resorptions, and of fetal mortality.     

草鱼母源免疫的初步研究

用酚灭活的柱状嗜纤维菌对草鱼雌亲鱼每月注射１次，连续注射７次。通过检测草鱼雌亲鱼血液中吞噬细胞的吞噬活性、血清中凝集抗体效价、受精卵和鱼苗中凝集抗体效价，首先证明了草鱼雌亲鱼对免疫原能产生较强的免疫应答，其凝集抗体可以通过受精卵而传递给仔代，而且这种凝集抗体能在孵化后的鱼苗体内持续存在２７ｄ以上。然而，用活菌对１７４日龄的鱼种攻毒的试验结果表明，免疫组与对照不存在显著差异。     

中华蜜蜂卵显微注射试验初报

用显微注射技术给１日龄中华蜜蜂（Ａｐｉｓｃｅｒａｎａｃｅｒａｎａ）卵注射石蜡油,置于（３４±１）℃恒温箱中让其继续发育至孵化．设置只移植不注射石蜡油的卵和在巢房块中的卵分别作对照．注射石蜡油的中蜂卵平均孵化率为３５．１３％;只移植不注射石蜡油的中蜂卵平均孵化率为８０．７４％;在原巢房中的中蜂卵平均孵化率为９９．３３％．经注射石蜡油的中蜂卵胚胎发育时间稍有延长．     

Structure and organization of the living mitotic spindle of Haemanthus endosperm

New details of mitotic spindle structures in the endosperm of Haemanthus katherinae (Bak) have been demonstrated by differential interference microscopy. Spindle fibers are clearly seen in the living spindle extending from the kinetochores to the polar region. Individual spindle fibers consist of a bundle of smaller filaments which diverge slightly from the kinetochore and intermingle with filaments from other spindle fibers as they approach the polar region. The degree of intermingling increases during metaphase and anaphase. The chromosomes stop moving when the spindle fibers are still 5 to 10microns long; then the fibers disappear. These observations explain some aspects of spindle movements which were difficult to reconcile with earlier concepts of spindle organization.     

飞蝗几丁质合成酶2基因的表达特性、功能及调控

【目的】几丁质合成酶（chitin synthase,CHS）是昆虫几丁质合成过程中的关键酶之一,由于高等动物不存在该酶,而被认为是设计安全高效杀虫剂的潜在靶标。论文在已克隆得到飞蝗几丁质合成酶2基因cDNA序列（LmCHS2,GenBank登录号：GU067731）的基础上,进一步深入探讨该基因在不同发育时期的表达特性、功能及调控,为基于RNA干扰技术的飞蝗有效控制提供科学依据。【方法】根据已知LmCHS2 基因核苷酸序列,设计特异性表达引物,运用RT-qPCR技术研究该基因在卵、若虫及成虫期的表达特性;体外合成LmCHS2的dsRNA后,分别注射至成虫期第1天的雌虫和雄虫,收集第5天的中肠样本提取RNA,反转录成cDNA后,采用RT-qPCR方法检测LmCHS2沉默效果。解剖飞蝗整个肠道后,观察中肠的形态变化及围食膜的完整性,探讨该基因在成虫期的生物学功能;饥饿处理飞蝗不同时间后,再重新进食,观察试虫肠道的变化,进一步运用RT-qPCR技术检测LmCHS2的表达。【结果】LmCHS2在飞蝗卵发育的前期和中期几乎没有可检测到的表达,卵发育后期表达量急剧上升,在4龄、5龄若虫和成虫期稳定表达;分别对羽化后第1天的雌、雄成虫注射dsCHS2,与对照组相比,处理组试虫LmCHS2表达量均显著下降,且取食量明显减少,雌虫和雄虫死亡率分别达78%和85%;解剖消化道后发现,注射dsCHS2后飞蝗中肠几乎不含有食物,中肠和胃盲囊长度显著缩短;对中肠的组织学观察结果表明对照组飞蝗围食膜发育完整,而注射dsCHS2后围食膜被严重破坏甚至缺失;饥饿处理飞蝗48 h后,与对照组相比,饥饿组中肠几乎不含有食物,长度亦显著缩短。H&E染色结果表明,饥饿组围食膜被严重破坏,对照组围食膜结构完整,与RNAi的结果非常相似;重新进食后围食膜发育良好;饥饿处理24 h和48 h后LmCHS2的表达被显著抑制,重新进食0.5 h后,其表达量快速上调,表明进食影响LmCHS2的表达。【结论】LmCHS2参与中肠围食膜的形成,对飞蝗的生长发育至关重要,该基因的沉默影响中肠围食膜的完整性,使飞蝗对食物的消化吸收困难,最终因饥饿而死亡;此外,该基因的表达受飞蝗进食的调控。     

Intravenous injection of thalidomide in pregnant rabbits

When administered orally to pregnant strain III rabbits, thalidomide is teratogenic to their fetuses. However, when the drug is injected intravenously to females of the same genetically controlled stock, it has no observable effect. This finding indicates that a metabolite of thalidomide formed in the intestinal tract may be the real teratogenic agent.