微注射MT-hGH融合基因后小鼠原核卵体外发育和移植的研究

将MT-hGH(小鼠金属巯因启动子--人生长激素基因)融合基因,用微注射的方法注入昆明白小鼠原核卵的雄原核中,观察注射外源基因对原核卵的存活,卵裂及2细胞胚胎体外发育的影响。实验结果表明,昆明白小鼠原核卵在雄原核内注射2p1 MT-hGH基因悬液后存活率为86.71％,其存活率与只穿刺雄原核不注射:注射培养液;注射TE缓衡液后存活率相近(分别为84.94％,84.4％和86.42％)。基因注射后原核卵存活率降低主要由注射针机械刺激引起的。原核卵在注射MT-hGH基因后注射胚卵裂率显著降低,以培养24h统计。注射培养液组活胚卵裂率为93.98％,丽注射基因组仅为87.96％(P<0.01)。注射MT-hGH基因组在体外培养条件下,2细胞到胚泡的发育率为40.66％,而注射培养液的对照组为64.09％(P<0.05)。注射基因组胚胎发育速度延缓,部分胚胎延缓12h。将基因注射后的原核卵经体外培养形成的198枚2细胞胚。45枚桑椹胚和161枚胚泡,移植给54只假孕受体,其中16只受体妊娠,产仔49只。目前存活25只。85日龄时。有6只小鼠体重为对照组平均体重的1.207～1.353倍,生长速度较快。经检测其中有5只呈阳性反应为转基因小鼠。     

Vill转基因小鼠的制备

摘要:目的　通过制备Vill转基因小鼠研究该基因的功能。 方法与结果　首先由RT-PRC方法获得全长约2605bp的Vill基因;经T载体克隆测序验证后,以克隆载体pMD19-T-Vill为模板,设计引物并引入酶切位点,将PRC扩增产物与pEF6/V5-His-LacZ同时进行酶切、连接,构建表达载体pEF6/V5His-Vill;经真核表达验证后,酶切获得含Vill基因的显微注射DNA构件;显微注射390枚受精卵后,在出生存活的77只仔鼠中获得转基因阳性GO代小鼠19只,其中16只能够稳定遗传并建系,转基因阳性小鼠外观未有明显改变。 结论　Vill转基因小鼠为该基因的功能研究准备了实验材料。     

产生乳腺定位表达人CD14的转基因小鼠研究

将来自ＰＣＲ法合成的绵羊β－乳球蛋白基因（ＢＬＧ）５’端８９８ｂｐ上游区和人单核细胞表面分化抗原基因（ｈＣＤ１４）成熟肽１２４５ｂｐ片段构建的ＢＬＧ－ｈＣＤ１４融合基因纯化后,注入小鼠受精卵原核。实验共注射受精卵１１４９枚,经体外培养发育到２－细胞期的胚胎计９６８枚,发育率为８４．２％。从发育的胚胎中选择６３４枚移植到４６只假孕受体。其中１４只妊娠产仔,妊娠率３０．４％。妊娠受体共移植胚移２０７枚     

小鼠转基因及传代研究

综述了湖北省农科院生物技术研究所近年来有关转基因小鼠的主要研究进展。应用原核注射技术 ,将POMT PGH、hDAF、pBHSA、pSHSA、PT HBV 1 3、Bcl xL、hCD5 9、hCD5 9+hMCP等 8种外源基因 ,注入并移植 4 874枚小鼠的受精卵 ,得到 5 5 6只小鼠 ;经PCR和Southern杂交检测 ,确认原代转基因小鼠 10 8只。基因整合率平均 19.4 % ,转基因效率平均 2 .2 %。应用混合注射的方法得到了转双基因小鼠 ,双基因共整合率 2 2 .2 %。表达外源蛋白的转基因小鼠在 5 0 %～ 10 0 %之间。研究了小鼠的超数排卵和影响转基因效率的几个因素。通过转Bcl xL小鼠与非转基因小鼠连续五个世代的传代交配和检测 ,研究了转基因小鼠外源基因的遗传规律 ,表明四只原代小鼠中 ,只有一只能稳定地将外源基因传递给后代。并非所有的转基因小鼠都具有遗传的稳定性 ,欲建立小鼠的转基因品系 ,尚需对原代转基因小鼠进行筛选。     

小鼠精子微注射受精卵的体外发育与移植的研究

用显微注射方法,将精子注入小鼠卵母细胞卵周隙中,使精卵体外受精获得受精卵。并对精子注射后卵母细胞的成活率、受精率和受精卵的发育率以及移植后受胎率等方面进行了系统的研究,结果表明:卵子存活率为75.36％(1309/1737),其中264枚卵裂,受精率为20·17％(264/1309),卵裂卵经体外培养后有192枚发育到桑椹胚及胚泡期,发育率为72.73％(192/264)。将其中73枚(桑椹胚10枚,肛泡63枚)胚胎移植到10只假孕受体子宫中,一只受体妊娠产仔9只,仔鼠发育正常。     

Plcd1转基因小鼠的制备

通过制备Plcd1转基因小鼠研究Plcd1基因功能.首先逆转录PCR获得约2.2kb的Plcd1基因全长,T载体克隆后测序验证;以pMD19-T-Plcd1为模板,通过设计引物及PCR扩增引入酶切位点,与pEF6/V5-His同时进行酶切、连接,构建pEF6/V5-His-Plcd1表达载体;经真核表达验证后,酶切获得目标片段,显微注射681枚受精卵,在82只仔鼠中获得转基因阳性首建鼠15只,其中13只稳定遗传并建系.PLCD1-HIS融合蛋白在睾丸组织中表达,在皮肤组织中无表达.Plcd1转基因小鼠为Plcd1功能研究奠定了基础.     

乙型肝炎病毒转基因小鼠外源基因的复制和传代稳定性观察

目的研究乙型肝炎病毒(HBV)转基因小鼠外源基因的复制、传代稳定性.方法通过nest-PCR和Southern分子杂交等检测方法,对48#、87#、90#三个系列中各15只整合阳性小鼠定期进行血清中HBV DNA存在情况以及对各系列繁育F1-F5代小鼠外源基因整合传代进行检测.结果各系列转基因鼠血清都有HBV DNA存在,并以1月龄时血清中HBV DNA阳性率最高,但随月龄改变,其DNA阳性率也变化,并存在系列、个体及月龄上的差异.结论HBV基因可在转基因小鼠体内复制、传代,且目前已稳定传至第五代(F5).     

以精子载体法制备转基因小鼠的初步研究

将外源融合基因BaLA-HI与DOSPER脂质体等比较混合,加入获能精子悬液中,37度,5％CO2共培养0．5h,以这种处理精子作为转基因载体乾鼠的体外受精及胚胎移植,在获得的40只移植后代后,经PCR特异片段扩增和Southern杂交,共检测出2只呈相性的转基因小鼠,证明人胰 基因已在小鼠染色体上实现了整合,基因整合率为5％。     

微注射MT-hGH融合基因后,小鼠原核卵体外发育和移植的研究

用微注射方法,将MT-hGH融合基因注入昆明白小鼠原核卵的雄原核中,观察外源基因或其它成分(培养液,TE缓冲液),注入原核后对原核卵的存活率,卵裂率和体外培养条件下胚胎发育的影响。原核卵在雄原核内注入2pl MT-hGH基因悬液后存活率为86.17％,与只穿刺雄原核但不注射,注射培养液或TE缓冲液后存活率相近(分别为84.94％,84.49％和86.42％)。原核卵在注射MT-hGH基因后体外培养24h,活胚卵裂率显著降低(对照组为93.98％,注射组为87.96％P<0.01),注射MT-hGH基因组在体外培养下,2细胞胚到胚泡期的发育率明显低于对照组(分别为40.66％和64.09％,P<0.05)。注射组胚胎发育速度延缓。     

转基因小鼠乳腺表达人乳过氧化物酶的初步研究

从人基因组PAC文库中筛选出人乳过氧化物酶（hLPO）基因,利用长片段PCR的方法获得hLPO基因5’端约3kb片段,通过酶切方法获得hLPO基因3’端约27kb片段,将这两部分拼接并克隆到乳腺特异性表达载体pBC1上,构建以山羊β-casein启动区指导的hLPO的转基因表达载体pBC1-hLPO。利用显微注射的方法获得28只FO代小鼠,经PCR检测和Southerm杂交分析证实,有5只小鼠（4♂,1♀）为整合hLPO基因的转基因阳性小鼠,整合率为17.86％,整合拷贝数在1至5之间。利用SDS-PAGE凝胶电泳和Western blot印迹分析FO、F1代共3只雌性转基因小鼠乳样,结果表明hLPO重组蛋白的特异条带不明显。     

Specific expression of an elastase-human growth hormone fusion gene in pancreatic acinar cells of transgenic mice

Transfection of genes into tissue culture cell lines has demonstrated that relatively short DNA sequences can allow expression of immunoglobulin, insulin and chymotrypsin genes in their appropriate cell types. A definitive test of cell-specific gene expression, however, requires testing genes in every possible cell type, an experiment performed easily by introducing the gene in question into the germ line of an animal. Transfer of intact genes into mice has demonstrated that a mouse immunoglobulin kappa gene is expressed specifically in B lymphocytes, a rat elastase I gene is expressed specifically in pancreas and a chicken transferrin gene is expressed preferentially in liver. Mouse metallothionein-growth hormone fusion genes introduced into mice are preferentially expressed in the liver, consistent with the expression of endogenous metallothionein genes, but initial experiments with beta-globin genes have not revealed proper regulation. To identify the DNA elements required for pancreas-specific expression of the rat elastase I gene, we joined the 5'-flanking region of this gene to the human growth hormone (hGH) structural gene and introduced the fusion gene into mice. Here we demonstrate that a fusion gene containing only 213 base pairs (bp) of elastase I gene sequence directs expression of hGH in pancreatic acinar cells.     

Novel developmental specificity in the nervous system of transgenic animals expressing growth hormone fusion genes

The development of methods for introducing foreign genes into the germ line of mice provides an approach for studying mechanisms underlying inducible and developmental gene regulation. Transgenic animals expressing foreign genes have thus been used to test models of the role played by specific DNA sequences in determining cell-specific expression. Results from these experiments suggest that tissue-specific expression is the consequence of a cis-acting regulatory sequence. However, these results do not exclude the possibility that cell-specific expression of some genes might be 'coded' by combinations of regulatory elements. We have previously described the production of transgenic mice from eggs microinjected with metallothionein-I/growth hormone (MGH) fusion genes, and now demonstrate that the juxtaposition of sequences from two different genes can be deciphered by cells to generate novel tissue specificities. Although expression of the endogenous metallothionein and growth hormone genes has not been detected in neuronal cells, transgenic mice clearly express an MGH fusion gene in a restricted subset of neurones. These results suggest a model in which tissue-specific patterns of expression of certain genes are determined by combinations of cis-acting regulatory sequences.     

Production of transgenic rabbits, sheep and pigs by microinjection

Direct microinjection has been used to introduce foreign DNA into a number of terminally differentiated cell types as well as embryos of several species including sea urchin, Candida elegans, Xenopus, Drosophila and mice. Various genes have been successfully introduced into mice including constructs consisting of the mouse metallothionein-I (MT) promoter/regulator region fused to either the rat or human growth hormone (hGH) structural genes. Transgenic mice harbouring such genes commonly exhibit high, metal-inducible levels of the fusion messenger RNA in several organs, substantial quantities of the foreign growth hormone in serum and enhanced growth. In addition, the gene is stably incorporated into the germ line, making the phenotype heritable. Because of the scientific importance and potential economic value of transgenic livestock containing foreign genes, we initiated studies on large animals by microinjecting the fusion gene, MT-hGH, into the pronuclei or nuclei of eggs from superovulated rabbits, sheep and pigs. We report here integration of the gene in all three species and expression of the gene in transgenic rabbits and pigs.     

HIV-1和HBV复合型DNA免疫的初步研究

近年的研究表明,在啮齿类和非人灵长类免疫带有编码病毒和细菌抗原基因的质粒ＤＮＡ可以激发体液和细胞免疫应答．在本实验中,将ＨＢＶ的Ｓ基因和ＨＩＶ－１的ｇｐ１６０基因以融合形式插入到载体ｐｃＤＮＡ３中,其能表达ＨＢｓＡｇ和ｇｐ１６０的融合蛋白,并将此质粒ＤＮＡ分别直接注射到Ｂａｌｂ／ｃ小鼠和Ｓｗｉｓ小鼠．三次免疫后,用ＥＬＩＳＡ的方法初步检测ＨＢｓＡｇ和ｇｐ１６０抗原特异的抗体免疫应答均为阳性．结果说明,带有ＨＢＶ和ＨＩＶ－１融合基因的质粒ＤＮＡ直接免疫小鼠后,均激发了小鼠产生相应的免疫应答反应,这个结果为研究和生产多价疫苗提供了新的思路     

SV40 enhancer and large-T antigen are instrumental in development of choroid plexus tumours in transgenic mice

We have shown recently that choroid plexus tumours frequently develop in transgenic mice which have developed from fertilized eggs injected with DNA molecules containing both simian virus 40 (SV40) early-region genes and metallothionein (MT) fusion genes, and several lines of mice have now been established in which all of the offspring that inherit the foreign DNA succumb to these tumours at 3-5 months of age (ref. 1 and our unpublished data). Several other tissues, notably thymus and kidney, occasionally also show pathological changes. SV40 large-T antigen protein and messenger RNA are always present in affected tissues at much greater concentrations than in unaffected tissues, suggesting that SV40 early-region genes are preferentially activated in choroid plexus, thymus and kidney and that this activation frequently leads to tumorigenesis in the choroid plexus. To determine which regions of the original constructs are important for this tumorigenesis, we have now tested several derivatives and report here that the large-T antigen is sufficient, that the MT fusion gene is dispensable and that the SV40 enhancer (72-base-pair repeat region) has an important role in directing tumours to the choroid plexus. Deletion of the SV40 enhancer region alone commonly leads to peripheral neuropathy, as well as liver and pancreatic tumours, which are the subject of the accompanying paper. Evidence is presented that these pathologies may result from an enhancing effect of the MT sequences on large-T antigen genes, made possible by removal of the otherwise dominant SV40 enhancer.     

基因工程小鼠剖宫取胎的适宜条件

目的　净化升级基因工程小鼠。方法　采用统计学方法对基因工程小鼠剖宫取胎净化过程中的大量数据进行分析。结果　①按规律准确判断妊娠天数 ,可使剖得的仔鼠成活率达到 81 0 % ,②CD_1小鼠作为代乳母鼠剖得的仔鼠离乳成活率为 5 1 5 %。结论　适宜的剖宫取胎条件是提高剖出仔鼠和离乳仔鼠成活率的关键。     

Effect of HS2 and HS3 elements on erythroid-specific expression in transgenic mice

The expression plasmids CMV/GFP, HS2ALL, HS3ALL and HS23ALL were selected to investigate the effect of HS2 and HS3 element on erythroid-specific expression in transgenic mice. These plasmids were digested with restriction enzymes and purified. And five DNA fragments, CMV/GFP, HS2/GFP, CMV/HS2/GFP, HS23/GFP and HS3/GFP were obtained. After purification, the above DNA fragments were microinjected into the pre-nuclei of the mice fertilized eggs and transgenic mice were generated, with an integration rate of 10.89%. The green fluorescence protein(GFP) expression in many transgenic mouse tissues was determined by FACS analysis. The results showed that the HS2 and 1.7 kb of β-globin gene promoter were sufficient for the erythroid-specific expression of β-globin gene. The GFP expression of different recombinant constructs was also analyzed in blood of all the transgenic mice with FACS. The results indicated that HS2 and HS3 had the same enhancement activity on the regulation of β-globin gene expression. Moreover, these two elements showed a significant synergistic effect on gene expression at the transgenic mouse level, although the GFP expression varied largely among different transgenic mouse litters.     

Peripheral neuropathies, hepatocellular carcinomas and islet cell adenomas in transgenic mice

The ability to introduce foreign DNA into the genome of mice offers unique opportunities to produce new models of disease process. Recent experiments have shown that integration and expression of simian virus 40 (SV40) T antigen genes and the murine mammary tumour virus (MMTV)-myc genes in transgenic mice can lead to the development of neoplasia in a remarkably tissue-specific manner. In the case of SV40-bearing mice, tumours consistently develop in the choroid plexus. In the accompanying paper, we show that the 72-base pair (bp) enhancer in the SV40 genome is instrumental in directing tumorigenesis to the choroid plexus. However, when the enhancer is deleted from a construction also containing the metallothionein-human growth hormone fusion gene (SV delta e-MGH), an entirely new pattern of pathology results. The present report focuses on transgenic mice carrying this construct; they develop demyelinating peripheral neuropathies, hepatocellular carcinomas and islet cell adenomas.     

Expression of the E. coli uvrA gene is inducible

UvrA+-dependent excision repair is one of the most important systems in Escherichia coli for repairing UV-induced pyrimidine dimers and a variety of other forms of DNA damage. The uvrA protein acts in conjunction with the uvrB and uvrC gene products to introduce a nick at the of a DNA lesion and thus initiate the repair process. We have recently used the Mud(Ap, lac) operon fusion vector to identify a set of genes whose expression is induced by DNA damage. One Mud(Ap, lac) insertion mapped at the uvrA locus and made the cells sensitive to UV light. In this fusion strain, beta-galactosidase expression was induced by DNA-damaging agents in a recA+lexA+-dependent fashion. We were surprised by this result because uvrA+-dependent excision repair is observed both in cells in which protein synthesis has been inhibited and in recA- and lexA- cells, findings which have led to the conclusion that the uvrA gene product is constitutively expressed and not under the control of the complex recA+lexA+ regulatory circuitry (see below). We have investigated this possibility further and describe here the generation and characterization of a set of fusions of the lac genes to the promoter of the uvrA gene. We confirm that the uvrA gene product is induced by DNA damage in a recA+lexA+-dependent fashion.