Development of gynogenetic eggs in the mouse: implications for parthenogenetic embryos

Mouse eggs with different genetic constitutions were prepared by micromanipulation of fertilized diploids and triploids. The diploid gynogenones, activated by the male gamete which was then removed, developed at best to about the 25-somite stage as did the genetically similar diploid parthenogenones stimulated to develop in the complete absence of the male gamete. The failure of development to term in both cases may be due to homozygosity and does not appear to be due to a lack of extragenetic contribution from spermatozoa.     

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.     

牛体外成熟卵母细胞死精子微注射受精研究

本研究主要目的是应用死精子微注射法探索一种提高牛成熟卵母细胞体外受精的方法。试验划分为三个部分：试验１体外成熟卵母细胞分为４个处理组。１组和３组成熟卵母细胞分别用１μｍｏＬ·Ｌ－１和５μｍｏＬ·Ｌ－１的钙离子Ａ２３１８７激活；２组和４组卵母细胞在１μｍｏＬ·Ｌ－１和５μｍｏＬ·Ｌ－１的钙离子Ａ２３１８７激活前去除颗粒细胞。精子获能用４０ｍｇ·Ｌ－１肝素。在试验２和试验３，成熟卵母细胞的激活方法和颗粒细胞的去除同试验１，精子获能分别用５０ｍｇ·Ｌ－１和１００ｍｇ·Ｌ－１肝素。当卵和精子经上述处理后，一个获能后的死精子微注射到卵细胞质中。试验结果表明：体外成熟的牛卵母细胞，当用５μｍｏＬ·Ｌ－１钙离子Ａ２３１８７激活后，经死精子显微注射，受精率明显地高于１μｍｏＬ·Ｌ－１的钙离子激活组。当精子获能用不同剂量的肝素处理后，对牛体外成熟的卵母细胞受精率未产生明显的影响。在死精子显微注射受精过程中，当成熟牛卵细胞在钙离子激活前去除颗粒细胞将明显地降低其受精率。     

利用水平微注射技术制备转基因兔的研究（英文）

利用常规微注射系统进行原核胚转基因时,由于其透光性能较差,操作不便等原因,使外源基因导入效率很低,另外其开放构造也易造成污染。为了解决这些问题,本研究有针对性地设计了新型的水平微注射系统,利用此系统,可明显缩短常规注射原核胚的平均时间,注射后原核胚的分裂率、8～16细胞胚胎发育率也明显提高。此外,利用该系统还可在低倍镜下（×100）将DNA常规注射量减半注射,提高了原核胚注射后的成活率,其注射胚的外源基因整合率亦明显提高。采用水平微注射系统,以pMT-hIGF-1为目的基因,在移植产下的24只仔兔中,有5只经Southern blot检测,证明为整合外源基因的转基因兔。     

Human beta-globin gene sequences injected into mouse eggs, retained in adults, and transmitted to progeny

Foreign gene sequences were retained in two adult mice (out of 62 analyzed) from fertilized eggs injected with a recombinant plasmid containing the human beta-globin genomic region and the herpes simplex viral thymidine kinase gene. The intact human and viral genes were found in DNA of one of the animals and, in the other, at least part of the human globin gene was present. The latter individual transmitted these sequences to its progeny in a Mendelian ration. Thus, human DNA may be incorporated into the germ line of mice for in vivo studies of regulation of gene expression in development, genetic diseases, and malignancy.     

转人MCP和CD59双基因小鼠的制备

采用显微混合注射的方法制备转人MCP(膜辅因子蛋白)和CD59(膜反应性溶解抑制物)双基因小鼠,共注射478枚受精卵,移植于21只受体,其中14只受孕,8只受孕小鼠中途流产,从6只受孕小鼠获得18只仔鼠,经检测,其中9只仔鼠单基因阳性(50％),6只仔鼠双基因阳性(33．3％)。结果表明：通过显微混合注射的方法可以获得转人MCP和CD59双基因小鼠。     

显微注射胚胎干细胞对长爪沙鼠胚胎发育的影响

将不同数量的成系的小鼠胚胎干细胞(ES细胞)显微注射注入长爪沙鼠(Merionesunguiculatus)的不同胚期的胚胎中,研究其对胚胎发育的影响,以期初步探索嵌合胚胎制作的条件。试验结果表明,显微注射2～5、6～10和11～15个ES细胞数量之间对早囊/囊胚期胚胎的成活率和孵化率的影响均不显著,但显微注射11～15个ES细胞的成活率和孵化率较低,分别为82.14%和64.29%;显微注射2～5个ES细胞的成活率和孵化率均较高,分别为90.90%和78.79%。显微注射11～15个ES细胞和未经显微注射的胚胎成活率分别为95.12%和82.14%,差异极显著(P<0.01);孵化率分别为90.48%和64.29%,差异极显著(P<0.01)。不经显微注射的桑椹/囊胚、经显微注射的8～16-细胞期胚胎和早囊/囊胚,其成活率分别为94.92%、91.53%和87.50%,差异均不显著(P>0.05);从孵化率来看,未经显微注射的桑椹/囊胚和经显微注射的8～16-细胞期胚胎其孵化率分别为89.83%和61.02%,差异极显著(P<0.01)。     

大雁卵与鹅卵几种物理性状比较研究

通过对16枚大雁卵和20枚鹅卵的主要物理性状指标的测定、计算,获得它们的蛋形指数、蛋壳厚度以及蛋清、蛋黄和蛋壳在总重量中各自所占比例等指标,经统计分析分别得出了蛋重和蛋黄重,蛋重与蛋壳比例,蛋壳厚度与蛋壳的比例等几对性状之间的相对关系。结果表明,鹅卵重量大于大雁卵,大雁卵蛋壳厚度大于鹅卵,而两者的其他物理性状的变化规律基本一致。     

鸡蛋中沙门氏菌的快速检测

选择江苏省不同地区来源的鸡蛋296枚,分别取蛋黄蛋清混合液以沙门氏菌增菌液快速增菌.取增菌培养物100 μl,离心去上清后,重新悬浮于100 μl超纯水中;以煮沸法制备可能存在的细菌DNA模板.通过对沙门氏菌毒力岛SPI-3的mgtC基因的PCR快速检测,确定其中18.24%的鸡蛋为沙门氏菌阳性.通过与细菌分离检测结果对比,揭示该方法明显提高了沙门氏菌的检出率,表明PCR是一种快速、敏感和高度特异性的沙门氏菌检测方法,值得在畜产品沙门氏菌的检测中推广应用.     

陆良县农函大蚕桑专业办学浅议

蚕种是蚕茧生产的基础,直接影响蚕茧产量、质量和丝厂效益.20世纪90年代,陆良县的当家品种为菁松×皓月,年发种量占总饲养量的90%以上.该品种在全国推广应用已20年,在陆良县饲养已10多年,随着饲养年限的延长,该品种的一些优良特性已逐步退化.     

中华蜜蜂卵冷冻贮存技术

以中华蜜蜂（Ａｐｉｓｃｅｒａｎａｃｅｒａｎａ）为材料，用玻璃化法进行了反复多次的卵冷冻试验．结果表明：卵冷冻的最适剂型为颗粒冷冻，最适的冷冻保护剂为体积分数为０．２５甘油＋０．２５乙二醇＋１．０ｍｏｌＬ－１蔗糖，预冻的时间为２ｍｉｎ，离液面的高度为２ｃｍ，脱除冷冻保护剂用的稀释液以６．５ｇＬ－１的生理盐水为最好．现已初步获得成功：冷冻后的中华蜜蜂卵能正常孵化为幼虫，但其孵化率较低（２５．０％～３７．５％），育王时尚不能被工蜂所接受．对此，今后仍需进一步试验．     

鸡蛋磺胺间甲氧嘧啶残留研究

随机选择32周龄、体质量1.6 kg的蛋鸡80羽进行试验,在饮水中分别添加159 mg·L^-1(标签推荐最高剂量)和79.5 mg·L^-1的磺胺间甲氧嘧啶,连续用药5 d,分别作为高剂量组和低剂量组,停药后收集鸡蛋样品。鸡蛋样品采用QuEChERS方法进行前处理,采用超高效液相色谱-串联质谱(UPLC-MS/MS)对鸡蛋样品中磺胺间甲氧嘧啶的残留量进行定量测定。结果发现,高剂量组在休药后第1、3、5、10、16、20、24天鸡蛋磺胺间甲氧嘧啶残留量分别为2 497.3、220.1、38.9、6.0、1.3、0.5、0.1 μg·kg^-1,低剂量组在休药后第1、3、5、10、16天鸡蛋磺胺间甲氧嘧啶残留量分别为694.3、45.2、15.5、1.5、0.1 μg·kg^-1。磺胺间甲氧嘧啶在鸡蛋中的消除速率为0.4~0.6 μg·kg^-1·d^-1。高、低剂量组分别在停药后第5天和第3天鸡蛋中磺胺间甲氧嘧啶残留量低于国家限量标准。从食品安全角度考虑,如采用标签推荐最高剂量,建议休药期控制在5 d以上。     

The Effect of Intra-cerebral Microinjection with Daidzein on the Plasma LH Level in the Castrated Boars

Daidzein (DA) was microinjected into mediobasal hypothalamus (MBH) and nucleus ventromeplasma luteinizing hormone (LH) levels were compared between the prior and the posterior treatment. The result showed that LH levels after the cerebral administration (ad) tended to increase compared to the levels before ad. In MBH, LH levels in 4 cases (4/5), rose and were not changed in 1 case at 0.5 - 2 hours after ad compared to those before ad. There were no significant changes at 2.5 hours after ad. When it was injected in VM, LH levels in 3 cases (3/4) rose, and were not changed in 1 case after ad compared to those before ad. In the control, there were no changes in plasma LH levels between the pre-and post-treatment except 1 case in MBH. This study suggested that DA could up-regulate LH secretion through hypothalamus level in the castrated boars.