牛胎儿成纤维细胞分离与体外培养

本研究以 4 5d牛胎儿为材料 ,使用 0 .2 5 %胰酶 + 0 .0 4 %EDTA消化液 ,分离得到牛胎儿成纤维细胞 ,体外培养传代至第 2 8代。本实验描绘出牛胎儿成纤维细胞生长曲线 ,并发现α MEM是一种适合牛胎儿成纤维细胞生长的培养基。分离得到的牛胎儿成纤维细胞传至第 1 8代时核型仍然正常 ,冷冻、解冻后细胞可继续传代     

牛胎儿成纤维细胞的分离培养

研究了牛胎儿组织成纤维细胞的分离、培养、纯化方法和生长特征,并对培养细胞的冷冻保存和复苏进行了观察.采取组织块培养法进行原代培养,在接种第5天到第6天成纤维细胞生长旺盛;用0.25%胰蛋白酶消化,传代培养细胞生长状态良好;用液氮冷冻法保存传代细胞,解冻后持续传代至第12代仍生长良好,第8代细胞冻存前和复苏后的活率分别为97.0% 和94.3%,无显著差异(P>0.05);分离纯化的胎牛成纤维细胞的生长曲线都正常;成功地建立了牛胎儿成纤维细胞系.该细胞可经多次传代培养和冷冻保存.     

牛胎儿皮肤成纤维细胞的分离培养及转染Ipr1基因

为了为核移植提供供体细胞,本研究构建了真核表达载体PEGFP-SRA-Ipr1,并研究了牛胎儿皮肤成纤维细胞的体外分离培养,进行了Ipr1基因转染.克隆Ipr1基因和SR-A启动子,并构建了巨噬细胞特异性真核表达载体.用组织块贴壁法分离培养牛胎儿皮肤成纤维细胞,在体外经传代、纯化后,用电穿孔法将真核表达载体PEGFP-SRA-Ipr1转染至经体外纯化的第4～10代牛胎儿成纤维细胞,24 h后观察荧光表达,48 h后加入600μg·mL-1 G418,筛选1周,300 p.g·mL-1持续筛选,然后挑选单克隆,继续扩大培养.对稳定转染的牛胎儿成纤维细胞进行PCR检测和核型分析.结果,转染24 h后有绿色荧光蛋白表达,并经G418筛选获得稳定转染PEGFP-SRA-Ipr1的牛胎儿成纤维细胞株,经PCR检测在大约1500 bp处有目的片段,经流式细胞仪分析转染细胞染色体倍型未发生变化,仍是二倍体.说明目的基因已经成功整合,同时保持了遗传稳定性.可以作为核移植进行转基因克隆牛研究.     

猪胎儿成纤维细胞和耳皮肤成纤维细胞培养方法的研究

为了研究猪胎儿成纤维细胞和耳皮肤成纤维细胞的分离培养体系,根据取样组织的不同,筛选出最佳的培养方法,试验以猪胎儿和耳皮肤为试验材料,用4种不同的培养分离方法,即胰酶热消化法、胰酶冷热结合消化法、胰酶室温消化法和组织块培养法,分离培养猪胎儿成纤维细胞和耳皮肤成纤维细胞,对比培养效果,筛选出最佳的培养方法。结果表明:胰酶室温消化法分离的猪胎儿成纤维细胞存活率显著高于胰酶热消化法和胰酶冷热结合消化法(P<0.05),细胞贴壁效果好,且操作简单;猪耳皮肤成纤维细胞原代培养中,胰酶热消化法和胰酶室温消化法分离的细胞数量少,组织块培养法所需的组织量少,且较胰酶冷热结合消化法操作简单。试验中培养的细胞呈典型的成纤维细胞形态,生长曲线呈"S"型,经冻存复苏后生长状态良好,说明胰酶室温消化法是猪胎儿成纤维细胞较好的培养方法,胰酶热消化法和胰酶室温消化法是猪耳皮肤成纤维细胞原代培养的理想培养方法。     

VPA对牛胎儿成纤维细胞体外培养的影响

为了研究组蛋白去乙酰化酶抑制剂(HDACIs)丙戊酸(VPA)处理对牛胎儿成纤维细胞体外培养的影响,试验采用培养到第3代的牛胎儿成纤维细胞经VPA处理后,进行细胞生长曲线绘制及形态、活力、细胞周期的检测,并通过Real-time PCR检测Oct4和Cdx2的表达情况,经梯度浓度的VPA处理牛胎儿成纤维细胞,于24 h后观察细胞形态。结果表明:当VPA浓度高于0.5 mmol/L时,细胞开始出现异常形态,死细胞数目增多。0.5 mmol/L VPA处理牛成纤维细胞24 h可以显著抑制细胞活力,可将60%以上细胞的周期阻滞在G0/G1期;但处理48 h将导致细胞染色体整倍率显著下降。与对照组相比,VPA处理后,Oct4的表达量显著升高,而Cdx2基因的表达量则显著降低。说明用HDACIs VPA处理过的牛成纤维细胞作为体细胞核移植的供体细胞,可能更有利于克隆胚胎重编程及发育。     

鲁西黄牛皮肤成纤维细胞分离与培养的研究

研究了鲁西黄牛耳皮肤成纤维细胞的分离与培养、纯化方法及生长特征,获得了传代培养的鲁西黄牛皮肤成纤维细胞和上皮细胞.鲁西黄牛耳皮肤细胞在体外培养时呈贴壁生长,其原代或早期传代培养物由上皮样细胞与成纤维细胞混合组成.传代培养混合生长的细胞用0.25%胰蛋白酶液37℃下消化处理3～4 min,脱壁悬浮的主要为成纤维细胞.采用反复消化法在传代过程中将二者逐步分离纯化,获得了可正常传代的鲁西黄牛耳上皮细胞系和成纤维细胞系.通过绘制生长曲线研究了鲁西黄牛耳皮肤成纤维细胞的增殖规律.传代培养至12代的鲁西黄牛皮肤成纤维细胞染色体倍性正常.利用第6代成纤维细胞作核供体克隆试验结果证明重构胚体外发育正常,囊胚发育率为27.3%.     

不同冷冻保护剂和冷冻方法对小鼠耳皮肤成纤维细胞冻存效果的影响

通过比较不同冷冻保存方法和冷冻保护剂对小鼠耳皮肤成纤维细胞冷冻-解冻复苏后细胞存活率、48h贴壁率和细胞生长曲线的影响,筛选适宜的小鼠耳皮肤成纤维细胞冷冻保存方法和冷冻保护剂。结果表明,以100mL/L二甲基亚砜(DMSO)作为冷冻保护剂进行小鼠耳皮肤成纤维细胞冷冻保存时,方法3处理组解冻复苏后细胞存活率和培养48h细胞贴壁率均高于方法2处理组(P>0.05),并分别极显著高于方法1和方法4。采用方法3进行冷冻保存时,以100mL/L DMSO作为冷冻剂的细胞贴壁率显著高于100mL/L甘油(GL)组(P<0.05),且冷冻解冻后的细胞呈现正常的分裂增殖生长模式。因此,宜选择100mL/L胎牛血清(FBS)+100mL/L DMSO+DMEM作为冷冻保护液,采用方法3进行小鼠耳皮肤成纤维细胞的冷冻保存。     

兔胎儿成纤维细胞的分离培养和鉴定

本研究旨在建立稳定传代的兔胎儿成纤维细胞系及其鉴定方法。取配种后14~15d的兔胎儿,0.25%胰酶消化胎儿皮肤获得兔胎儿成纤维细胞,体外传代培养;通过观察细胞形态、测定生长曲线、免疫荧光染色、核型分析等鉴定兔胎儿成纤维细胞,PCR扩增SRY基因鉴定2株细胞系性别。研究结果表明,兔胎儿成纤维细胞呈梭形,可在体外快速生长,符合"潜伏期-对数期-平台期"的生长规律;免疫荧光染色结果显示,波形蛋白与纤维连接蛋白染色为阳性,细胞角蛋白染色为阴性,表明兔胎儿成纤维细胞纯度高,活性好;染色体检测结果显示,在传至第5代时,80%的成纤维细胞核型正常,为2n=44,属正常范畴;PCR法检测的2株细胞系均来源于兔雄性胎儿。综上表明,本研究建立了兔胎儿成纤维细胞系体外培养、传代、鉴定及其性别鉴定方法,可为转基因兔、克隆兔、兔诱导性多能性干细胞等研究提供充足、可靠的成纤维细胞来源。     

溶葡萄球菌素基因乳腺特异表达载体的构建与检测及转基因核供体细胞的制备

本研究旨在构建溶葡萄球菌素基因牛乳腺特异表达载体(pEPB),转染牛胎儿成纤维细胞,为制备溶葡萄球菌素基因的转基因克隆牛提供核供体细胞.本研究以pEGFP-C1为载体骨架,通过PCR扩增牛2.6 kb的β-酪蛋白5′调控区及0.6 kb的3′侧翼区(poly A)序列作为调控序列,制备成含有绿色荧光和新霉素筛选标记的牛乳腺特异表达载体,经PCR和酶切鉴定正确后,用转染试剂FuGene HD反复转染牛pEPB乳腺上皮细胞3～5次,用催乳素诱导后,经免疫荧光分析,检测目的蛋白的表达.然后,用电转染法转染牛胎儿成纤维细胞,经G418筛选得到阳性细胞后,把阳性细胞扩大培养并提取其基因组,因为溶葡萄球菌素基因是外源基因,经PCR及Southern blot 检测来确定目的基因是否已经整合到细胞的基因组上.结果表明,溶葡萄球菌素基因在牛乳腺细胞中得到了表达,并整合到牛胎儿成纤维细胞的基因组中,得到了转溶葡萄球菌索基因的核供体细胞.结果显示,本研究所获得的转基因牛胎儿成纤维细胞可作为体细胞核移植的供体细胞进行转基因克隆牛研究.     

以两种不同成纤维细胞为饲养层培养牛胚胎干细胞的比较

牛胚胎干细胞的培养一直未能确定最适合的饲养层,寻找一种适合于其生长的饲养层对于成功培养牛胚胎干细胞有重要意义。本研究以胎鼠和牛胎儿为材料,分别以含10%FBS的高糖DMEM和含10%FBS的DMEMF12为培养液,分离并且获得2～5代的胎鼠成纤维细胞和5～6代的牛胎儿成纤维细胞。在上述两种成纤维细胞为饲养层的条件下,采用含10%胎牛血清、0.1 mmol/Lβ-巯基乙醇、0.1 mmol/L非必须氨基酸、100 U/mL青霉素、0.05 mg/mL链霉素、20 ng/mL LIF和10 ng/mL bFGF的DMEMF12培养液培养牛胚胎干细胞,来寻找一种适合于牛胚胎干细胞培养的饲养层。结果表明,在相同的培养体系条件下培养牛胚胎干细胞,以胎鼠成纤维细胞为饲养层的贴壁率显著高于以牛胎儿成纤维细胞为饲养层的贴壁率(P0.05),以牛胎儿成纤维细胞为饲养层更利于胚胎滋养层的去除。     

Autosomal trisomy 20 (61,XX,+20) in a malformed bovine fetus.

A 240-day-gestation female bovine fetus with severe anasarca, palatoschisis, cheiloschisis, mild cranioschisis, and a flattened facies was collected at a slaughterhouse, and a fibroblast line was established from the fetal skin. Chromosome preparations were Q-banded, and chromosome counts were taken that indicated the presence of 61 chromosomes in cells of the fetus (the normal diploid number for domestic cattle is 60). Q-band karyotypes were constructed, and Q-band analysis revealed the presence of three copies of chromosome 20. Trisomy 20 (61,XX,+20) was confirmed through the use of two-color fluorescence in situ hybridization of bovine bacterial artificial chromosome clones that were specific to chromosome 20 and the X chromosome.     

不同培养体系对胎牛成纤维细胞体外培养的影响

研究不同培养体系对胎牛成纤维细胞体外培养的影响及用牛血清白蛋白代替血清培养胎牛成纤维细胞的可行性。利用M199、DMEM、α-MEM、DMEM/F124种培养体系通过组织块贴壁培养对成纤维细胞体外培养液进行筛选,以α-MEM组细胞生长状况较好。分别用含2、4、6、8、10mg/mL BSA的α-MEM培养液对胎牛成纤维细胞进行原代及传代培养,5种浓度的BSA对原代培养时细胞开始游离出组织块的时间影响不明显,均在培养后的48h有成纤维细胞和上皮细胞混合游离出,但在传代培养时,胎牛成纤维细胞在8mg/mL BSA浓度的α-MEM中贴壁率较高。结果表明:培养胎牛成纤维细胞时,可用BSA代替血清,较适宜的培养体系为含8mg/mL BSA的α-MEM培养液。     

马皮肤成纤维细胞的分离与体外培养

研究用小组织块直接培养法和酶消化法成功地分离了马皮肤成纤维细胞,并对其进行了体外培养,同时筛选出消化马皮肤组织块的适宜酶及酶浓度,获得了马皮肤成纤维细胞的生长曲线,并发现至少在传至第12代时有81.3%的染色体还保持正常的倍数(2n=64)。     

Cytogenetical and molecularbiological studies on a bovine XY female.

A bovine XY female in Holstein-Friesian heifer, which appeared as female with uterus and ovaries but did not show the estrus until 23 months old after the birth, was cytogenetically and molecularbiologically examined. As results of chromosome analysis, leucocyte and fibroblasts from skin, spleen and kidney examined had only metaphase plates with 60, XY. From these results and the clinical characteristics, this case was clearly diagnosed as a pure XY female. It was ascertained that the two genes, ZFY and AMG gene which located on the short arm of the Y chromosome (Yp) were detected in normal bulls and a XY female, but were not detected in normal cow, mother cow and half-sib heifer by Southern blotting.     

昆明犬胎儿成纤维细胞系的建立及生物学特性分析

本研究旨在探索和建立昆明犬胎儿成纤维细胞体外分离、培养的技术方法并观察其生物学特性.试验利用剖腹手术法获得发育30 d的昆明犬胎儿12个,性别鉴定结果为7公5母.公、母胎儿体尺和体重分别为:体长1.90 cm±0.14 cm和2.00 cm±0.05 cm,体宽0.90 cm±0.13 cm和0.90 cm±0.15 cm;体重0.68 g±0.17 g和0.66 g±0.06 g,差异均不显著(P>0.05).以昆明犬胎儿组织为材料,采用胶原酶消化法和细胞冷冻保存技术建立了昆明犬胎儿成纤维细胞系,并对所构建的细胞系进行生物学特性研究.结果表明,分离的胎儿成纤维细胞呈典型的成纤维细胞形态,生长曲线呈S型,倍增时间约为36 h;冻存前和复苏后的存活率分别为96.1%和94.6%;染色体核型分析显示2n=78(XY),并在体外培养多代后仍能保持正常核型.本研究建立的昆明犬胎儿成纤维细胞系可在体外快速贴壁生长、增殖,进行稳定培养,这不仅使昆明犬遗传资源在细胞水平得以保存,且所获成纤维细胞能作为相关研究中所需细胞的来源.     

CRISPR-Cas9介导的蒙古牛MSTN基因敲除细胞系的建立

试验旨在利用CRISPR-Cas9技术对蒙古牛胎儿成纤维细胞肌肉生长抑制素（myostatin,MSTN）基因进行编辑,构建无标记的MSTN基因敲除的蒙古牛细胞系,为培育肌肉发达的蒙古牛提供试验材料。通过组织块贴壁法对妊娠45 d的蒙古牛胎儿建立皮肤成纤维细胞系,同时在第2外显子区域选定1个gRNA靶位点,使用在线软件设计sgRNA序列,并选取评分较高的3个sgRNA,采用试剂盒法构建无标记的Cas9/gRNA载体,随后用T7E1酶酶切法对其进行活性验证,将有活性的载体用电转法转染蒙古牛胎儿成纤维细胞,通过无限稀释法和口吸管法将转染后的单细胞接种于96孔板扩繁后提取DNA,对其进行PCR扩增及测序验证来获取阳性细胞。本试验构建了3个无标记的CRISPR-Cas9载体,经验证1个有活性,对电转染后的单细胞进行筛选共获得96个单细胞株,测序分析后有1个单细胞株发生单碱基突变,使得MSTN基因不能编码正常的蛋白。试验成功建立了1个MSTN基因失活的细胞株,可作为后续体细胞核移植的供体细胞,用于生产无标记的敲除MSTN基因的蒙古牛,对培养产肉率高并具有生物安全性的蒙古牛具有重要的意义。     

Physiologic studies of maturity diagnosis in the calf and its relationship to the postnatal condition

The parameters of kidney, lung, and skin maturity, known from human medicine, were for the first time determined from amniotic fluid of cattle. Given the difference in placentation, it is not known whether the conditions of the human fetus can be fully applied to the bovine fetus, the detectability of such maturity criteria may be indicative of comparable morphokinetic conditions in the bovine fetus. All physiological parameters investigated exhibited difference to the benefit of surviving calves. Positive correlations were found to exist between the lecithin/sphingomyelin quotient and body weight gain in the first week of age as well as drinking behaviour of the calves. Hence, insufficient concentration of surface-active phospholipids in calf breeding has measurable effects on quantitatively definable characteristics.     

Characterization of the bovine immunoglobulin lambda light chain constant IGLC genes

To characterize the bovine immunoglobulin lambda light chain constant region (IGLC) genes, we have isolated a bacterial artificial chromosome (BAC) clone by a PCR based approach from a bovine genomic DNA library, constructed using a genital ridge cell line derived from a male Holstein fetus. The positive BAC clone, containing the bovine IGLC genes, was fully sequenced and had a 138 kb insert. Sequence analysis revealed that the bovine immunoglobulin lambda light chain locus consisted of four joining-constant gene recombination units spanning approximately 20 kb DNA in length. A detailed examination of the recombination signal sequences, RNA splicing sites and coding sequences of the four joining-constant gene recombination units suggested that only two IGLC genes (IGLC2 and IGLC3) were functional while the IGLC1 and IGLC4 appeared to be pseudogenes. This conclusion was further confirmed by a series of RT-PCR amplifications, which also showed that among these four genes the IGLC3 was preferentially expressed in cattle. Phylogenetic analysis indicated that the bovine IGLC genes were more closely related to their equivalents in sheep and goats than that to other mammals.     

Bovine abortion associated with mixed Movar 33/63 type herpesvirus and bovine viral diarrhea virus infection.

A herpesvirus and cytopathogenic bovine viral diarrhea virus were isolated from a bovine fetus aborted in the 6th month of gestation. The herpesvirus was serologically indistinguishable from bovine herpesviruses DN-599 and Movar 33/63.