XBP1s条件性过表达定点敲入小鼠模型的建立

目的获得可进行条件性过表达XBP1s基因的Rosa 26定点敲入杂合子小鼠。 方法通过In-Fusion Cloning的方法构建胚胎干细胞(ES细胞)打靶载体,并进行线性化,电转染JM8A3 ES细胞。药物筛选获得抗性ES细胞克隆,经长片段PCR鉴定获得正确同源重组的阳性克隆。阳性ES细胞经克隆扩增后,注射入C57BL/6J小鼠的囊胚中,获得嵌合鼠,筛选出高比例嵌合小鼠与野生型C57BL/6J小鼠交配后获得阳性F1代小鼠,并分别进行PCR和测序鉴定。 结果经酶切鉴定证明打靶质粒构建成功,经胚胎干细胞打靶共获得144个抗性ES细胞克隆,通过长片段PCR的方式对同源重组阳性克隆进行筛选和克隆经测序确认,共获得21个正确同源重组的阳性克隆。阳性ES细胞克隆E3、C6经扩增后注射C57BL/6J小鼠囊胚96个,通过胚胎移植,共获得2只高嵌合雄鼠,与野生型C57BL/6J小鼠交配后获得3只F1代杂合小鼠,经PCR及测序鉴定正确。 结论成功建立了XBP1s基因的Rosa26定点敲入F1代杂合子小鼠,为未来获得免疫细胞、肾脏固有细胞及腹膜间皮细胞XBP1s条件性敲入小鼠奠定了基础。     

生长激素促分泌素受体基因敲除小鼠胚胎干细胞的建立

目的建立生长激素促分泌素受体（ghrelin receptor，GHS-R）基因敲除小鼠胚胎干细胞（ES细胞）杂合子模型，为研究GHS—R基因的功能奠定基础。方法用TK-neo置换原X-pPNT载体的PGK—neo构建目标载体。以小鼠基因组DNA为模板，用PCR方法扩增2条同源臂，将其按照一定方向装入含有TK—neo的X—pPNT载体，并测序鉴定。载体线性化及纯化后电穿孔转染小鼠ES细胞，用G418和更昔洛韦（Gancyclovir）对电穿孔转染后的ES细胞进行正、负筛选培养，得到双药抗性ES细胞，克隆后抽提基因组DNA，分别用PCR方法鉴定2条同源臂，并测序确定成功同源重组的ES细胞克隆。结果改建X—pPNT载体成功，PCR获得2条同源臂片段，测序正确，并按一定方向装入打靶载体，ES细胞转染后经双药筛选得到328个阳性ES细胞克隆，PCR及测序鉴定证实3个克隆发生同源重组。结论本研究成功获得了GHS-R（-／＋）杂合子小鼠ES细胞克隆，为进一步通过显微注射及杂交育种获得GHS—R基因敲除小鼠打下了基础。     

软骨细胞条件性敲除PTEN基因的FGFR3功能增强型点突变小鼠的获得及其表型初步分析

目的 获得在软骨细胞中条件性敲除PIEN基因的FGFR3增强型点突变小鼠并进行初步表型分析.方法 通过FTEN条件性基因敲除小鼠(Ptenflox/flox小鼠),与软骨细胞特异表达Cre重组酶的小鼠(Col2aCre)交配,获得在软骨细胞中特异敲除PTEN基因小鼠(Col2aCre:Ptenfolox/flox);同时,利用Ptenflox/flox小鼠与FGFR3增强型点突变小鼠(Fgfr3G369C/+小鼠,即ACH小鼠)交配,子代杂合子小鼠(Ptenflax/:ACH)之间再交配,获得Ptenflox/flox:ACH小鼠;通过Col2aCre:Ptenflox/flox和Ptenflox/flox:ACH交配即可获得在软骨细胞中特异性敲除PTEN基因的FGFB3增强型点突变小鼠((Col2aCre:Ptenflox/flox:ACH).采用PCR对小鼠基冈型进行鉴定,免疫荧光染色检测PTEN基因的敲除效率,通过X光平片摄影对小鼠的表型进行初步分析.结果 获得了在软骨细胞中敲除PTEN的FGFR3点突变小鼠,免疫荧光染色证实Col2aCre:Ptenflox/flox:ACH小鼠软骨细胞中PTEN蛋白因为基因敲除而表达很低.初步的表型分析显示:Col2aCre:Ptenflox/flox:ACH小鼠身长、尾长均较Pten flox/flox:ACH小鼠长(P＜0.05,n=5).Col2aCre:Ptenflox/flox:ACH小鼠表型,较Ptenflox/flox:ACH小鼠的侏儒表型有所缓解.结论 采用基于Cre/LoxP系统的条件性基因敲除策略,获得了在软骨细胞中敲除PTEN基因的FGFR3增强型突变小鼠,表型分析初步显示,软骨细胞特异性敲除PTEN基因可部分缓解由FGFR3增强型点突变所导致的小鼠侏儒表型.该小鼠的获得,为研究P13K/AKT信号通路在FGFR3突变介导的软骨生长抑制中的作用提供了实验动物平台.     

利用新型DNDF7和携带LoxP位点的LPL4质粒快速构建S-Sox5基因打靶载体

目的体外实验已证实S-SOX5蛋白转录调节运动纤毛基因Spag6,为进一步探索其在体内的作用,拟构建S-Sox5基因的敲除载体。方法利用新型DNDF-7和携带LoxP位点的LPL4载体,选择S-Sox5基因第1外显子作为条件性敲除目的片段,SV129系ES细胞DNA为模板分步扩增包括S-Sox5第1外显子的中间段(middle piece),上游同源左臂4.8kb(upper arm)及下游同源右臂2.5kb(down arm)的基因片段;构建upper-arm-DNDF7、down-armDNDF7和middle-piece-LPL4质粒,将middle-piece-LPL4的酶切产物LoxP-middle-piece-LoxP和down-arm-DNDF7酶切产物相连,形成携带LoxP位点的middle-down-arms-DNDF7重组质粒,该质粒与upper-arm-DNDF7酶切产物相连,获得S-Sox5基因打靶载体。结果经酶切鉴定及测序证实,构建的upper-arm—DNDF7、middle-piece—LPL4、down-arm—DNDF7重组质粒和S-Sox5基因打靶载体结构正确,与设计相符。结论成功构建小鼠S-Sox5条件基因打靶载体,为进一步建立S-Sox5条件敲除小鼠,在体内研究其功能打下基础。     

小鼠成纤维活化蛋白真核表达载体的构建及表达

目的 构建小鼠成纤维活化蛋白(FAP)基因的真核表达载体,并检测其在人胚肾细胞及小鼠体内的表达.方法 根据Gene Bank中mFAP基因(NM_007986)全序列设计聚合酶链反应(PCR)引物,获得其开放式阅读框(ORF).将目的基因片段克隆至真核表达载体pcDNA6/myc-His-B,转化并筛选.将重组质粒注射入小鼠尾静脉,在注射后1、3、5、7 d抽提小鼠腓肠肌组织的总RNA,检测FAP表达.结果 经过酶切鉴定、测序比对,确定所筛选的阳性克隆为pcDNA6-mFAP重组子,其可在真核细胞及小鼠体内正常表达,并产生相应蛋白质产物.在小鼠体内注射后第5天,重组子的基因(0.841±0.040)和蛋白表达量(85.380±4.425)%最高,和空白对照组比较差异有统计学意义(P<0.01).结论 成功构建FAP真核表达载体,为研究该基因产物的功能和进行疫苗抗肿瘤实验提供基础.     

携带白蛋白启动子和IDO基因重组腺病毒的构建

目的 构建携带小鼠白蛋白启动子和IDO基因的重组腺病毒载体,研究肝脏Hepa l石细胞的IDO基因mRNA及蛋白表达情况.方法 酶切含有小鼠全长IDO cDNA的IDO质粒,亚克隆至穿梭载体pAdTrack.ALB上,在BJ5183细菌中和AdEasy-1进行同源重组,生成并筛选阳性克隆,测序、鉴定正确后,转染AD-293细胞进行包装、扩增,检测病毒滴度,RT-PCR和荧光显微镜鉴定重组腺病毒转染AD-293细胞后IDO的表达.重组腺病毒进一步感染Hepa 1-6细胞,RT-PCR和WesternBlot法分别检测IDO基因在细胞内表达情况.结果 经酶切及测序证实携带白蛋白启动子和IDO基因重组腺病毒载体构建成功,RT-PCR检测到转染后AD-293细胞内IDO的表达,病毒感染滴度为2.9×10~6pfu/ml.感染Hepa 1-6细胞后,RT-PCR和Western Blot可以检测到IDO mRNA水平和蛋白水平表达.结论 构建了携带白蛋白启动子和IDO基因的重组腺病毒载体.     

克隆与表达产甲酸草酸杆菌代谢基因Frc及临床意义

目的研究产甲酸草酸杆菌草酸代谢基因Frc转化大肠杆菌BL21后稳定表达代谢草酸相关性酶--甲酰辅酶A转移酶(FCoAT)对草酸的降解效能。方法成功培养产甲酸草酸杆菌后,采用PCR方法从产甲酸草酸基因组中获得Frc基因,克隆到pMDTM19-T载体上进行测序,得到正确的基因片段。经双酶切将目的基因片段插入到原核表达载体PGEX-4T-2上,测序正确后,转化大肠杆菌BL-21,IPTG诱导表达GST-FCoAT融合蛋白,表达产物行western-blot鉴定分析。结果重组克隆载体pMDTM19-Frc经测序鉴定序列正确。成功构建融合原核表达质粒PGEX-4T-2-Frc,大肠杆菌BL21成为载体,并稳定表达可溶性融合蛋白GST-FCoAT的同时获得代谢草酸潜能。结论克隆产甲酸草酸杆菌Frc基因,成功构建PGEX-4T-2-Frc载体,并转化大肠杆菌BL21,能稳定表达可溶性融合蛋白GST-FCoAT,具有代谢草酸潜能,为肠道细菌获得代谢草酸潜能,减少胃肠道内草酸的吸收,降低尿液中草酸含量和临床防治草酸结石的研究奠定理论基础。     

成骨诱导双基因共表达腺病毒载体的构建

目的 探讨用一条Link序列T2A连接骨形态发生蛋白-2(BMP-2)基因与碱性成纤维细胞生长因子(bFGF)基因构建含目的 基因的腺病毒载体的可行性.方法 先从cDNA中扩增得到全长BMP-2和bFGF基因片段,再接于Link序列T2A的两端.通过T2A Peptide的互补.延伸得到BMP2-T2A-bFGF的全长PCR产物,利用上游引物的Bgl Ⅱ酶切位点和下游引物的EeoRV酶切位点将其插入到pShuttle-IRES载体中,酶切、测序鉴定;利用同源重组技术将目的 基因表达框从穿梭质粒转移到腺病毒载体,鉴定阳性克隆;将PacI线性化后的腺病毒载体转染到293A细胞,观察GFP表达,PCR鉴定后进行大量扩增,并用CsCl梯度离心法进行纯化;测量A260,计算病毒感染滴度.结果 克隆得到的BMP-2与bFGF基因测序正确.经BglⅡ和EeoR Ⅴ双酶切得到的BMP2-bFGF 2个基因全长序列完全克隆到穿梭质粒和重组腺病毒载体质粒中;转染293A细胞2周后观察到明显的GFP聚集表达,即病毒包装成功,扩增纯化后滴度为3.6×1011 VP/ml.结论 经酶切鉴定BMP-2与bFGF双基因共表达腺病毒载体构建成功.     

间质细胞双尾C基因条件性敲除小鼠模型建立及其表型分析

目的构建间质细胞双尾C(Bicc1)基因条件性敲除小鼠模型, 并对其表型进行分析。方法将CRISPR Cas9方法构建的Bicc1f/+小鼠子代与Pdgfra启动子驱动的Cre小鼠进行杂交, 获得子代小鼠, 饲养1～2周后提取其脚趾及鼠尾组织基因组DNA, 经PCR扩增及琼脂糖凝胶电泳后, 在DNA水平检测小鼠基因型;选取经鉴定后生长至3周龄的Bicc1基因条件性敲除小鼠(实验组)、野生型小鼠(对照组)各3只进行后续实验:通过腹腔注射他莫昔芬进行诱导敲除Bicc1基因, 于1周后取小鼠肾脏、骨骼肌、皮肤及脂肪组织, 一部分组织通过实时定量PCR(RT-qPCR)鉴定其中的Bicc1 mRNA表达水平;另一部分组织以10%多聚甲醛固定, 随后进行HE染色和Masson染色, 在光镜下观察分析。应用SPSS 28.0软件对数据进行分析, 组间比较采用t检验, P<0.05表示差异有统计学意义。结果通过繁育获得间质细胞Bicc1基因条件性敲除小鼠, 基因型为Bicc1f/fCre+/-, 野生型小鼠基因型为Bicc1f/fCre-/-;RT-qPCR检测结果显示, 实验组小鼠肾脏、骨骼...     

骨形态发生蛋白-2基因的克隆及重组真核表达质粒的构建

目的 克隆骨形态发生蛋白-2(BMP-2)基因,并构建重组BMP-2基因真核表达质粒.方法 从兔骨髓细胞中分离提取BMP-2的mRNA,RT-PCR扩增后,克隆入pGEM-T载体,PCR鉴定重组子;酶切下目的 基因BMP-2,再亚克隆入载体pEGFP-C3质粒,酶切鉴定亚克隆重组子并进行DNA序列分析.结果 经过RT-PCR扩增得到BMP-2cDNA条带:PCR扩增鉴定得到pGEM-T-BMP-2.酶切鉴定得到亚克隆重组子pEGFP-C3-BMP-2,经测序鉴定证实插入DNA序列与设计完全一致.结论 成功克隆兔BMP-2基因,构建出重组真核表达载体BMP-2,为进一步采用BMP-2基因治疗关节软骨缺损奠定了实验基础.     

Up-Regulation of Donor Dendritic Cell PD-L1 Expression Reduced Recipient Lymphocyte Activation and Proliferation In Vitro

ObjectiveTo observe the effects of dendritic cells (DC) in donor C57BL/6 (H-2^b) micetransfected with recombinant adenovirus vector Ad-PD-L1 on proliferation and activation of lymphocytes in recipient DBA/2 (H-2^d) mice.MethodsThe pSport 1-mSD274 plasmid containing the full-length PD-L1 cDNA of the mouse was digested and subcloned to the shuttle plasmid pShuttle-GFP-CMV(-), and then the adenovirus skeleton plasmid pAdxsi-GFP-CMV-PD-L1 was constructed by enzymolysis and ligation, transformed into DH5α sensitive bacteria, and screened for positive clones. After enzyme digestion, sequencing, and identification, 293 cells were transfected with liposome after linearization for packaging and amplification, and the virus was purified by cesium chloride density gradient centrifugation. DC of donor C57BL/6 mice were isolated, cultured, and divided into the following 3 groups: group A, adenovirus vector Ad-PD-L1 transfection group; group B, empty vector transfection group; and group C, control group. Western blot was used to detect the expression of PD-L1 in each group of cells after transfection. Isolate lymphocytes from recipient DBA/2 mice were labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE) and mixed with DC of donor C57BL/6 mice with lymphocytes of recipient DBA/2 mice. Flow cytometry was performed to observe the proliferation of lymphocytes.ResultsDigestion and sequencing confirmed that the recombinant adenovirus vector Ad-PD-L1 containing PD-L1 was successfully constructed. After transfection with DC of donor C57BL/6 mice, the expression of PD-L1 increased by 37% (P < .05), and the PD-L1 transfected DC and recipient DBA/2. Mouse lymphocytes were cocultured. Compared with the control group, the increased expression of PD-L1 significantly inhibited the proliferation and activation of lymphocytes. The lymphocyte proliferation of DBA/2 mice decreased by 41% (P < .01).ConclusionThe recombinant adenovirus vector Ad-PD-L1 containing the mouse PD-L1 gene was successfully constructed. After transfection with dendritic cells of donor C57BL/6 mice, PD-1/PD-L1 inhibited lymphocytes proliferation and activation of recipient DBA/2 mice through costimulatory pathway.     

小鼠主要组织相容性复合物基因各位点的提取和质粒的构建

目的 提取小鼠的主要组织相容性复合物(MHC)基因各个位点,构建质粒,以用于转基因实验.方法 提取小鼠RNA,逆转录cDNA,以嵌套聚合酶链反应(PCR)的方法扩增,将产物与T载体连接、克隆和测序;用内切酶切下,再与表达型载体连接,再次测序挑选克隆.结果 嵌套PCR后,产物通过测序证实为目的 基因序列,与T载体、表达型载体的连接和克隆后,经测序证实并挑选得到了正确的克隆.结论 MHC各位点基因可以通过嵌套PCR扩增获得;构建的表达型载体质粒可用于今后转入受者的实验.     

Deletion of nicotinamide nucleotide transhydrogenase: a new quantitive trait locus accounting for glucose intolerance in C57BL/6J mice

The C57BL/6J mouse displays glucose intolerance and reduced insulin secretion. The genetic locus underlying this phenotype was mapped to nicotinamide nucleotide transhydrogenase (Nnt) on mouse chromosome 13, a nuclear-encoded mitochondrial protein involved in beta-cell mitochondrial metabolism. C57BL/6J mice have a naturally occurring in-frame five-exon deletion in Nnt that removes exons 7-11. This results in a complete absence of Nnt protein in these mice. We show that transgenic expression of the entire Nnt gene in C57BL/6J mice rescues their impaired insulin secretion and glucose-intolerant phenotype. This study provides direct evidence that Nnt deficiency results in defective insulin secretion and inappropriate glucose homeostasis in male C57BL/6J mice.     

Control of expression of insulin resistance and hyperglycemia by different genetic factors in diabetic C57BL/6J mice

The inheritance of the tendency to develop diet-induced non-insulin-dependent (type II) diabetes was analyzed in crosses between diabetes-prone C57BL/6J (BL/6) mice and diabetes-resistant A/J mice. The effects of a diabetogenic diet on blood glucose and insulin levels, insulin sensitivity, and weight were evaluated in F1 and both (BL/6 X A/J) F1 X BL/6 and (BL/6 X A/J) F1 X A/J backcross mice. These results suggest that diet-induced hyperglycemia is largely determined by a recessive gene and diet-induced insulin resistance by a dominant gene. Analyses of both backcrosses indicated that insulin sensitivity and blood glucose levels were unrelated, suggesting that they are controlled by different genetic factors. This conclusion was supported by data from nine recombinant inbred BXA strains in which no correlation was observed between these variables. Furthermore, insulin sensitivity and body weight correlated differently in the two backcross groups, suggesting that insulin resistance is not simply a function of obesity. The number of genes that predominantly influence diabetic traits was estimated by comparing the variance observed in (BL/6 X A/J) F1 X BL/6 backcross mice with that observed in parental mice. The data suggest that relatively few genes predominantly affect the diabetic phenotype in this murine model.     

负载PCA3启动子及CD-TK自杀基因腺病毒载体的构建及包装

目的 构建负载PCA3启动子联合CD-TK基因的腺病毒载体,并对其进行包装及滴度测定.方法 将PCA3启动子无缝克隆到pHBAd-U6-GFP上,取代原有U6启动子形成pHBAd-PCA3-GFP,AgeI单酶切该重组载体,将CD-TK基因片段无缝克隆至线性化pH-BAd-PCA3-GFP上,抽提质粒抗性筛选后经PCR及测序鉴定为pHBAd-PCA3-CD-TK载体.取上述重组载体质粒及骨架质粒pHBAd-BHG,用LipofiterTM转染试剂进行转染HEK293细胞包装成病毒,大量扩增并测定病毒感染性滴度.结果 经PCR及测序验证证实成功构建负载PCA3启动子及CD-TK自杀基因的重组腺病毒pHBAd-PCA3-CD-TK并包装扩增,病毒滴度为1×1010PFU/mL.结论 构建负载PCA3启动子及CD-TK自杀基因的重组腺病毒,为进一步体内外对前列腺癌细胞的杀伤效应研究奠定了基础.     

胚胎干细胞移植修复脊髓损伤的实验研究

目的观察胚胎干细胞（embryonic stem cell,ES）诱导的神经前体细胞移植,对小鼠脊髓损伤神经功能恢复的影响。方法取由上海市发育生物学重点实验室提供的ES进行细胞培养和体外诱导,收集ES衍生细胞。并进行RT-PCR检测。将50只C57/BL6J小鼠制备为T9、10脊髓半横断模型,将存活的28只小鼠随机分为三组。假手术组（A组）：9只,未作任何处理;手术/细胞组（B组）：10只,于距损伤区域以远约1cm的椎管内注射2~3μl制备的ES衍生细胞,总细胞数为9×105个;手术/DMEM组（C组）：9只,按B组方法注射2~3μl DMEM。术后1、2、4、6和8周采用BBB后肢功能评分观察小鼠神经功能恢复情况,取损伤脊髓进行X-gal染色和免疫组织化学染色观察。结果ES经体外诱导培养,呈圆形或椭圆形小集落生长,有1个或多个核仁。RT-PCR检测,ES细胞诱导后表达巢蛋白及微管相关蛋白,但未表达胶质纤维酸性蛋白。小鼠实验,BBB后肢功能评分显示术后各时间点A组与B、C组比较,差异均有统计学意义（P〈0.01）。B组与C组比较,1、2和4周时,差异有统计学意义（P〈0.01）;6、8周时,组间差异无统计学意义（P〉0.05）。X-gal染色观察,B组呈阳性染色,A、C组均为阴性。免疫组织化学染色观察,B组在损伤脊髓部位,表达兔抗神经微丝蛋白,未表达胶质纤维酸性蛋白。结论将ES培养诱导分化为神经前体细胞移植后,能够存活、迁移,并分化为神经元,但未明显改善神经功能。     

pET14b-His-TAT-ERK2和无活性突变体pET14b-His-TAT-ERK2(AF)原核表达载体的构建和表达

目的：构建基于转录激活因子（TAT）技术的细胞外信号调节激酶（ERK）2及其无活性突变体ERK2（AF）原核载体并在大肠杆菌BL21（DE3）中表达。方法：采用聚合酶链式反应（PCR）技术从pcDNA3-Flag-ERK2和pcDNA3-Flag-ERK2（AF）质粒中扩增出ERK2和ERK2（AF）基因,插入pET14b-His-TAT载体中,构建重组质粒pET14b-His-TAT-ERK2和pET14b-His-TAT-ERK2（AF）,并诱导原核表达、纯化融合蛋白。采用Western blot方法检测表达蛋白的His标签。结果：酶切和测序结果表明,扩增的ERK2和ERK2（AF）基因正确,大小为1082bp;10%SDS-PAGE凝胶电泳可见原核表达纯化得到高纯度目的蛋白,大小为41 kD;Western blot检测显示,原核蛋白带有His标签。结论：成功构建了ERK2和ERK2（AF）的原核表达载体,该载体能在大肠杆菌中表达,纯化得到了His-TAT-ERK2和His-TAT-ERK2（AF）蛋白,为研究ERK2蛋白的功能提供了重要工具。     

Mapping of putative ether-anesthesia resistance gene using C57BL/6J and MSM/Ms mouse strains

Purpose We attempted to identify the locations of major mouse genes responsible for sensitivity to diethylether (ether) anesthesia, using microsatellite linkage analyses including Quantitative Trait Locus (QTL) analysis.Methods To determine the locations of ether anesthesia resistance genes on chromosomes, an ether anesthesia-resistant mouse strain, C57BL/6J (C57BL), and an ether anesthesia-sensitive mouse strain, MSM/Ms (MSM), were used. The sensitivity of mice to ether anesthesia was determined from the latency time required to lose the righting reflex during exposure to 4% ether vapor in air. The (C57BL × MSM) F₁ mice were found to be resistant to ether, showing that the resistant phenotype is genetically dominant. Twelve resistant and 12 sensitive mice were then selected from the 196 backcrossed F₂ mice (F₁ × MSM) at 11–16 weeks of age. Genomic DNA samples were extracted from the tails for mapping ether anesthesia-related genes using microsatellite linkage analyses.Results One major putative gene related to resistance to ether anesthesia was restricted in the region 23 to 37cM from the centromere in chromosome 7 by primary and secondary linkage analyses. The QTL analysis narrowed the position of the gene to 29.0cM, with a maximum logarithm of odds (LOD) score of 3.03, and it was termed Etan1 (ether-anesthesia 1).Conclusion Microsatellite linkage analyses, including QTL analysis, determined the location of the ether-resistance gene, Etan1, within a narrow range. Our findings should be helpful for further experiments, such as cloning of the gene governing the sensitivity to ether anesthesia in mice.     

Lentivirus-based gene delivery in mouse embryonic stem cells

BACKGROUND: Embryonic stem (ES) cells are widely used in therapeutic research as an unlimited source of cell therapy. Therefore, it is of great value to find a way to efficiently manipulate ES cells. HIV-1-derived lentiviral vectors are now considered to be an efficient vehicle for delivering genes into a variety of cells. In this study, we examined the efficacy of lentivirus-based gene delivery into mouse ES (mES) cells. MATERIALS AND METHODS: Recombinant HIV-I-based lentiviral vectors Lt-GFP, expressing green fluorescent protein (GFP), and Lt-LacZ, expressing E. coli LacZ gene in conjunction with neomycin resistance gene, were generated using a FuGENE 6 transduction method and used for transducing ES cells derived from 129Sv mice. Lentiviral transduction efficacy was evaluated by GFP expression assay using flow cytometry and by X-gal staining. The in vivo potential of developing teratoma of such transduced mES cells was examined in severe combined immunodeficiency (SCID) mice. RESULTS: FuGENE 6 showed no considerable transduction-associated cytotoxicity. The expression rate of GFP and LacZ of mES cells increased on a multiplicity of infection (MOI)-dependent manner with the amount of Lt-GFP and Lt-LacZ used. Approximately 42% of mES cells were positive for GFP after infection of Lt-GFP at an MOI of 30. Notably, after G418 selection, nearly 100% of Lt-LacZ-transduced mES cells were positive for LacZ and formed teratomas in SCID mice. CONCLUSIONS: This work demonstrates that HIV-I-based lentiviral vectors are capable of transducing mES cells. Lentiviral vectors may facilitate an advance in the field of gene transfer and expression in various types of ES cells, including human ES cells.