HCK基因在大鼠胚胎心脏发育过程中的表达

目的检测HCK基因在大鼠胚胎心脏过程中的mRNA表达变化,分析其与心脏发育的关系。方法取大鼠胚胎d12、d15、d19心脏,采用半定量反转录聚合酶链反应(RT-PCR)技术检测心脏组织中HCK基因mRNA的表达丰度,并应用原位杂交的方法对其进行定位分析。结果在胚胎d12、d15、d19心脏中,HCK基因均有表达,但主要表达于心脏间质,在心肌细胞中不表达,其表达丰度分别为(0.19±0.09),(0.38±0.07),(0.59±0.10),随胚龄的增长有上调趋势(P<0.05)。结论HCK基因表达于心脏间质,在心肌细胞中不表达,并随大鼠胚胎心脏的生长发育呈动态表达,HCK可能与心脏发育相关。     

韧黏素在大鼠胚胎心脏发育过程中的表达

目的 检测韧黏素-C(TN-c)和韧黏素-X(TN-X)在大鼠胚胎心脏中的表达,探讨其在胚胎心脏发育过程中的作用.方法 雌性SD大鼠64只,雄性SD大鼠20只,雌雄同笼,以观察到雌鼠排出阴栓为妊娠0.5 d(ED 0.5),分别于ED 12.5、ED 15.5、ED 19.5处死孕鼠,取出心脏.半定量反转录酶聚合酶链反应(RT-PCR)检测上述各孕龄大鼠胚胎心脏中TN-C和TN-X mRNA表达;免疫组织化学染色法观察上述各孕龄大鼠心脏TN-C和TN-X蛋白表达.结果 TN-C mRNA在ED 12.5大鼠胚胎心脏中高表达(0.6837±00431),ED 15.5(0.4543±0.0388)和ED 19.5(0.2505 ±0.0384)大鼠胚胎心脏TN-C mRNA表达下降,与ED 12.5比较有显著性差异(Pa<0.05);ED 12.5、ED 15.5、ED 19.5大鼠心脏TN-X mRNA相对表达量分别为0.74711±0.0433、0.7584±0.070、0.767 1 ±0.088,各组间表达无显著性差异.免疫组织化学显示TN-c在ED 12.5大鼠胎心有表达,在ED 15.5少量表达,在ED 19.5大鼠心脏未见表达;TN-X在ED 12.5大鼠胎心的心室肌的细胞中有表达,在ED 15.5、ED 19.5胎鼠心脏中表达于整个心脏的心肌及房室间隔.结论 TN-c在胚胎心脏早期发育过程中可能占有重要作用,而TN-X可能是心脏存活所必须的.     

叶酸缺乏对孕鼠子代心脏中NKx2.5基因表达的影响

目的探讨叶酸缺乏孕鼠子代心脏发育过程中NKx2.5基因和蛋白表达改变。方法成熟雌性36只SD大鼠随机分为实验组和对照组各18只,分别喂以缺乏叶酸和添加叶酸的纯合饲料。2周后与成熟SD雄性大鼠交配,分别取孕13.5 d、孕17.5 d胚胎鼠及新生鼠心脏。用RT-PCR检测NKx2.5基因mRNA表达。Western-blotting测GATA-4蛋白表达水平。结果NKx2.5基因mRNA及其蛋白在孕13.5 d、孕17.5 d胚胎心脏及新生鼠心脏中的表达量,实验组均显著低于对照组(P均<0.05)。结论叶酸缺乏影响NKx2.5基因和蛋白表达水平,可能导致心脏发生发育中形态改变,从而造成心脏功能缺陷。     

dhfr基因过表达对乙醇致斑马鱼胚胎心血管发育异常的效应研究

目的 观察二氢叶酸还原酶基因（dhfr）过表达对乙醇致斑马鱼胚胎心脏和血管发育异常的作用,并初步探讨其机制。方法 体外转录dhfr mRNA并将其显微注射入斑马鱼受精卵内使dhfr基因过表达,并进行过表达的效率验证。将野生型斑马鱼分为正常对照组、乙醇处理组（400?mmol/L乙醇溶液）、乙醇+dhfr mRNA组（显微注射6?nL dhfr mRNA）,观察各组胚胎的整体发育情况。按照上述分组,利用红色荧光蛋白标记心脏的转基因斑马鱼系Tg（cmlc2：mcherry）观察胚胎心房和心室的发育状况;利用荧光显微造影观察野生型斑马鱼胚胎心脏流出道及血管发育情况;通过心率和心室收缩指数评估心功能情况。构建基因探针并通过胚胎整体原位杂交及Real-time PCR法,检测胚胎nkx2.5、tbx1、flk-1的基因表达情况。结果 与乙醇处理组相比,乙醇+dhfr mRNA组斑马鱼胚胎发育异常百分率明显下降,存活百分率显著上升（P < 0.05）;心房、心室、心脏流出道和血管发育的异常表型及心功能情况明显改善。乙醇处理组nkx2.5、tbx1、flk-1 mRNA的表达较对照组下降（P < 0.05）;乙醇+dhfr mRNA组nkx2.5、tbx1、flk-1 mRNA的表达较乙醇处理组上调,但仍未达到正常对照组水平（P < 0.05）。结论 dhfr基因过表达可部分挽救乙醇所致胚胎心脏和血管发育异常,其机制可能与dhfr基因过表达后上调乙醇导致的nkx2.5、tbx1、flk-1水平降低有关。     

Wnt5a及Frizzled-1基因在肛门直肠畸形大鼠直肠发育过程中的表达及义

目的 检测Wnt5a及Frizzled-1(Fzd-1)基因在肛门直肠畸形(anorectal malformations,ARM)胎鼠直肠肠壁的胚胎发育过程中的表达变化,探讨其可能与肠壁神经肌肉发育的关系.方法 将Wistar大鼠随机分为正常组与乙烯硫脲致畸的ARM组,应用免疫组化、Western Blot方法检测正常与ARM组胎鼠直肠末端组织Wnt5a及Fzd-1蛋白的定位及定量表达,RT-PCR方法检测Wnt5a及Fzd-1 mRNA的表达差异.结果 Wnt5a/Fzd-1在正常大鼠胚胎直肠发育过程中,在肠壁肌间神经丛(myenteric nerve plexus,MP)、肠壁平滑肌及黏膜层均有表达,随胚胎发育,表达强度逐渐增强,胚胎晚期主要集中在肠壁平滑肌及MP处;ARM组:越接近直肠末端的肠壁内阳性表达细胞明显减少.western blot及RT-PCR结果显示正常胎鼠直肠末端组织中Wnt5a及Fzd-1总蛋白量及mRNA明显高于畸形组(E21:Wnt5amRNA:0.81±0.14比0.21±0.03;Fzd-1mRNA:0.72±0.11比0.20±0.04;Wnt5a:1.12±0.11比0.48±0.05;Fzd-1:0.91±0.10比0.32±0.04,P<0.05).结论 Wnt5a/Fzd-1基因在肛门直肠畸形的神经肌肉发育过程中表达下调,可能与其发育不良有一定关系.     

HCK基因在小鼠胚胎干细胞向心肌细胞分化过程中的表达

目的 探讨HCK基因在小鼠胚胎干细胞向心肌细胞分化过程中的表达及HCK基因在维持胚胎干细胞未分化状态中的意义.方法 培养小鼠胚胎干细胞,并诱导其向心肌细胞分化.抽提其胚胎干细胞未分化及分化第2、4、6、8天的总RNA,应用反转录聚合酶链反应(RT-PCR)方法对HCK基因mRNA的表达进行半定量分析;同时抽提胚胎干细胞未分化及分化第2、4、6、8天的总蛋白,应用Western-blot方法对HCK蛋白的表达进行半定量分析.采用SPSS 11.5软件进行统计学分析,P＜0.05为有统计学差异.结果 HCK基因mRNA在未分化的胚胎干细胞(D0)及分化的第2天(D2)均有表达,而在分化的第4天(D4)开始已不能检测到有表达,HCK基因mRNA的表达水平随小鼠胚胎干细胞的分化呈急剧下调趋势;HCK蛋白的表达与mRNA的表达相一致,在小鼠胚胎干细胞的分化进程中逐渐下调,至第4天已基本检测不出.结论 HCK基因随着小鼠胚胎干细胞向心肌分化,表达呈下调的趋势,HCK基因可能在维持胚胎干细胞未分化状态中起重要作用.     

心脏α肌动蛋白基因在胚胎心脏发育中的时空表达

目的 了解心脏α肌动蛋白（cardiac alpha—actin,CAA）基因在胚胎心脏发育过程中的时空表达规律,探讨其与心脏畸形发生的关系。方法用电刺激方法制备鸡胚心脏畸形模型。用实时荧光定量PCR方法检测胚胎发育不同阶段CAA基因表达量的动态变化;用免疫组化方法检测CAA蛋白在胚胎不同发育时期表达部位的变化。结果（1）CAA基因在胚胎发育早期即开始表达。以后表达量逐渐增加至稳定。CAA主要局限在心脏部位表达,并随着心肌结构的发育成熟表达逐步增强;在肝脏、脑、胃等器官中不表达或微量表达。（2）心脏神经嵴被破坏的实验组胚胎在胚龄第2～7天,CAA基因相对表达量明显低于正常对照组胚胎相对应时期（P=0．013）。实验组心脏组织在第7、9、15天时CAA基因表达量也明显低于正常对照组（P=0．029）。结论CAA基因与心脏发育密切相关。CAA基因表达受到心脏神经嵴细胞调控,剔除心脏神经嵴后其表达减少,影响了心肌细胞的成熟和分化,可能是导致心脏畸形发生的一个重要因素。     

孕鼠叶酸缺乏对子代心脏叶酸结合蛋白1基因及WNT信号转导途径的影响

目的探讨孕鼠叶酸缺乏(FD)对子代心脏发育过程中叶酸结合蛋白1(Folbp1)基因表达及WNT信号转导途径的影响。方法成熟雌性SD大鼠36只随机分为实验组和对照组各18只,分别喂以缺乏叶酸和添加叶酸的纯合饲料。2周后与成熟SD雄性大鼠交配,分别取孕13.51、7.5 d胚胎鼠及新生鼠心脏。用RT-PCR方法检测Folbp1基因及WNT信号转导途径中Wnt和-βcatenin基因mRNA表达。结果Folbp1、Wnt及-βcatenin基因mRNA在孕13.51、7.5 d胚胎心脏及新生鼠心脏中的表达量,实验组均显著低于对照组(P均<0.05)。结论FD影响Folbp1、WNT及-βcatenin基因表达,可能引起叶酸受体功能低下和WNT信号转导途径障碍,从而可能导致心脏发育中形态异常,造成心脏功能缺陷。     

宫内抗雄性物质暴露对胎鼠及新生大鼠阴茎组织p53和细胞周期调节基因表达的影响

目的 观察宫内抗雄性物质暴露对胎鼠及新生大鼠阴茎组织p53和细胞周期调节基因(p21waf/cip1)表达的影响,探讨其与尿道下裂发病机制之间的关系.方法 将定期受孕的SD大鼠随机分为9 g·L-1盐水组(对照组)和氟他胺(Flu)组,于孕12～16 d分别腹部皮下注射Flu及9 g·L-1盐水100 mg·kg-1·d-1,2组动物均于胚胎19 d(GD19)及出生1 d(PND1)、4 d(PND4)、7 d(PND7)各随机取8只,应用反转录.PCR技术检测各组阴茎组织p53和p21waf/cip1基因的表达.结果 1.p53基因的表达:对照组在GD19～PND1随鼠龄增加,表达逐渐减弱,至PND1表达最弱,以后随鼠龄增加逐渐增强.Flu组在GD19～PND1随鼠龄增加逐渐增强,至PND1最强,以后随鼠龄增加而逐渐减弱,且Flu组在GD19和PND1表达均高于对照组(Pa<0.05).2.p21waf/cip1 mRNA的表达:对照组在GD19～PND1随鼠龄增加而增强,至PND1表达最强,以后随鼠龄增加逐渐减弱.而Flu组GD19～PND7随鼠龄增加呈逐渐减弱的趋势,且在GD19和PND4与对照组相比,差异均有统计学意义(Pa<0.05).结论 宫内抗雄性物质暴露可能通过上调p53基因表达,抑制胎鼠及新生大鼠阴茎组织细胞增殖,进而导致其尿道下裂发生.     

柯萨奇病毒B3病毒性心肌炎小鼠心肌组织微小RNAl初始体和连接蛋白43的表达

目的 观察柯萨奇病毒B3(CVB3)病毒性心肌炎(VMC)小鼠心肌组织微小RNA1初始体(pri-miRNA-1)和连接蛋白43(Cx43)的表达变化,探讨VMC室性心律失常的发生机制.方法 4周龄雄性Balb/c小鼠70只随机分为VMC组40只(14 d和28 d2个亚组各20只)和对照组30只(14 d和28 d2个亚组各15只).VMC组腹腔注射CVB3Nancy株悬液0.1 mL,对照组腹腔注射不含病毒的RPMI 1640培养基0.1 mL.2组小鼠分别在接种第14、28天无痛苦处死,取心室肌,采用反转录聚合酶链反应(RT-PCR)检测其心室肌组织pri-miRNA-1、dicer1 mRNA的表达,免疫组织化学法检测其Cx43的表达.结果 1. VMC组14 d和28 d小鼠心室肌组织pri-miRNA-1表达水平均显著高于对照组(0.82±0.04 vs 0.64±0.01,0.79±0.03 vs 0.62±0.01 Pa<0.01);2.VMC组14 d和28 d小鼠心室肌组织dicer1 mRNA表达水平均显著高于对照组(0.91±0.03 vs 0.72±0.02,0.87±0.02 vs 0.71±0.02 Pa<0.01);3.VMC组小鼠心室肌组织炎性病灶中变性、坏死周围心肌细胞Cx43表达明显减弱,甚至阴性,分布不规则,VMC组14 d和28 d亚组Cx43蛋白表达均显著低于对照组(0.27±0.01 vs 0.42±0.02,0.22±0.02 vs 0.44±0.02 P.<0.01);4.VMC组小鼠心室肌组织pri-miRNA-1表达水平与Cx43蛋白水平呈显著负相关(r=-0.798 P<0.01),与dicerl mRNA表达水平呈显著正相关(r=0.828 P<0.01).结论 VMC小鼠心肌组织pri-miRNA-1和dicer1参与了CVB3的发生机制,dicer1表达升高可能通过促进miRNA-1生成、抑制Cx43的表达促进室性心律失常的发生.实用儿科临床杂志,2009,24(10):754-756     

Cellular disorganization and extensive apoptosis in the developing heart of mice that lack cardiac muscle alpha-actin: apparent cause of perinatal death

Mice that lack cardiac muscle alpha-actin die during the perinatal period. Approximately 56% of mice that are homozygous null (-/-) for a functional cardiac alpha-actin gene do not survive to term, and the remainder generally die within 2 wk of birth. We found that there were neither morphologic differences nor differences in the extent of apoptosis between the mutant and normal hearts on embryonic day (E) 12 and E14 of development. However, apoptosis was greater in the hearts of homozygous null mice on E17 and postnatal day 1 when compared with wild-type hearts. The antiapoptotic factor Bcl-x/(L) was localized in regions adjacent to where apoptosis was detected. The distribution patterns of the apoptosis triggering protein p53 were similar to those of apoptotic cells. The growth of the prenatal and postnatal hearts of the cardiac alpha-actin-deficient mice was retarded, and the cytoplasmic filaments were disorganized. Although apoptotic cells were observed in both the atria and ventricles in the hearts of the homozygous null animals, the frequency was greater in the ventricles than in the atria. Our results indicate that the functional and structural disturbances in the mice with a homozygous lack of cardiac alpha-actin seem to be due to disorganized development of acto-myosin filaments in the affected cardiomyocytes. Other actin isoforms cannot compensate for the lack of cardiac alpha-actin, and this seems to induce apoptosis in defective cardiac myocytes, which are not able to cope with the increased workload in the perinatal phase.     

妊娠期糖尿病胎鼠心脏T-同源盒转录因子表达研究

目的 探讨T-同源盒转录因子5（TBX-5）在母鼠妊娠糖尿病（GDM）胎鼠心脏中的分布、表达规律及其在胎鼠心脏发育异常中的作用。方法 将成年SD雌鼠随机分成GDM组和对照组,通过阴道涂片确定怀孕后分别注射链脲佐菌素（STZ）及柠檬酸-柠檬酸钠缓冲液（PBS）制备GDM模型,于孕0、3、6、9、12、15、19天对母鼠进行尾静脉采血测血糖,并分别于孕后第12、15、19天进行胎鼠心脏取材,HE染色观察心脏组织病理变化,免疫组化检测TBX-5的表达并进行半定量检测。结果 与对照组相比,GDM组胎鼠出现液化吸收胎、死胎、畸心胎的例数增多（P〈0.01）。在大体观及高倍镜下,GDM组12、15、19天胎鼠心脏发育异常比例多于对照组（P〈0.01）。在正常对照组及GDM组各亚组中,TBX-5均在第12天时表达最强,明显高于15、19天（P〈0.01）。TBX-5在15天及19天时的表达无明显差别（P〉0.05）。孕12、15、19天GDM组TBX-5在心肌细胞表达显著增强,与相应时间点的对照组相比均明显增高（P〈0.01）。结论 TBX-5蛋白在妊娠糖尿病母鼠孕12、15、19天三个观察点胎鼠心脏的表达水平明显增高,提示其过度表达可能与妊娠期糖尿病致胎鼠心脏畸形的发生存在关联。     

Perinatal and postnatal expression of Cav1.3 α1D Ca²⁺ channel in the rat heart

The novel Cav1.3 (α1D) L-type Ca2? channel plays a significant role in sinoatrial (SA) and atrioventricular (AV) nodes function and in atrial fibrillation. However, the characterization of α1D Ca2? channel during heart development is very limited. We used real-time RT-PCR, Western blotting, and indirect immunostaining to characterize the developmental expression and localization of α1D Ca2? channel in rat hearts. Both protein and mRNA levels of α1D Ca2? channel decreased postnatally. Two forms of α1D Ca2? channel protein (250 and 190 kD) were observed, with the full-length (250 kD) channel protein being predominant in the prenatal stages. Both Western blots and confocal imaging demonstrated that α1D Ca2? channel protein was expressed in both atria and ventricles at fetal and neonatal stages but was absent in the adult ventricles. Interestingly, α1D Ca2? channel was also found at the nucleus/perinucleus of immature but not adult atrial cells. Furthermore, the nuclear staining was reproduced in adult atrial cell line, HL-1 cells, which possess immature properties. The data are first to show that α1D Ca2? channel has unique age-dependent expression profile and subcellular localization in the heart, suggesting a developmental stage-dependent specific function.     

The Distribution of Tenascin in Rat Embryos with Normal Heart and Cardiovascular Anomalies Induced by Bis-Diamine

The mesenchyme in the truncal ridge and aortico-pulmonary (A-P) septum in the developing heart expresses tenascin (TN), a component of extracellular matrices. We observed immunohistochemically the localization of TN with reference to fibronectin (FN) distribution in rat embryonic hearts at gestation days 12. 13 and 14 and compared the results with those in bis-diamine-induced cardiovascular anomalies. In control rat embryonic hearts, TN was distributed in the dorsal mesocardium and the distal part of the truncal ridge at gestation day 12, and in part of the conal and truncal ridges, A-P septum and proximal wall of aortic arch arteries at gestation days 13 and 14. The conotruncal regions with TN expression may correspond to the areas where cardiac neural crest cells migrate in the heart. In bis-diamine-treated rat hearts showing conotruncal anomalies, TN was localized in incompletely fused and hypoplastic conotruncal ridges, but the intensity and area of staining were decreased suggesting a decreased neural crest cell migration. FN was diffusely distributed in both the normal and anomalous embryonic hearts, including atrioventricular cushion tissue in addition to the region expressing TN. TN was densely distributed in the fusing area of the conal and truncal ridges in comparison to FN, suggesting that TN may be mainly expressed during the time of fusion of conal and truncal ridges to form the A-P septum in the embryonic heart. In conclusion, bis-diamine may cause the poor development of neural crest derived tissue, subsequently bringing about hypoplasia of the A-P septum and truncal and conal ridges.     

Pacemaker development in embryonic rat heart cultured in oculo

Conditions that cause pacemaker formation in the developing heart are poorly understood. Embryonic rat myocardium grafted into the anterior eye chamber of an adult rat provides a promising model system in which to study pacemaker development. Electrophysiologic mapping with two microelectrodes showed that each embryonic heart graft developed a primary pacemaker within the region of contact with the host iris. These single, primary pacemakers were found in the centers of graft-iris junctions both in grafts that originally contained the natural pacemaker (e.g. right atria and whole hearts) and in grafts that excluded the sinoatrial pacemaker region (i.e. ventricles and left atrial appendages). Pacemaker action potentials were recorded in the region identified by mapping as the origin of the impulse in 11 of 11 grafts. Action potentials recorded from surrounding working cells were similar to adult rat heart cells in maximum diastolic potential, overshoot, amplitude, and duration. In contrast, maximum upstroke velocity was consistently slower in grafts than in adult hearts. Beating of grafts slowed or stopped within 3 days after transplantation but resumed by 10-14 days at rates similar to those observed before dissection (265 +/- 12), a pattern consistent with development of a new pacemaker in oculo. The graft-iris junction is the site of blood vessel and nerve ingrowth into the graft and it is a region of contact between differentiated embryonic myocardial cells and nonmyocardial (iris epithelial) cells. The roles of these three factors (vascularization, innervation, and surface contact) in establishing the pacemaker were examined using embryonic heart cultured both in the anterior eye chamber and in vitro.     

Growth factors gene expression in the developing lung

AIM: This is the first systematic study using quantitative real-time PCR to analyze and compare the expression profiles for critical members of the epidermal growth factor (EGF), transforming growth factor beta (TGFbeta), and vascular endothelial growth factor (VEGF) families in developing rat lungs. METHODS: mRNA expression was quantified at embryonic (E) day 15, 17, 19, 21, and postnatal age 1 day, 2 weeks, 12 weeks. RESULTS: EGF and EGFR increased during gestation and development, then decreased in adulthood, whereas TGFalpha was highest at birth and remained unchanged afterwards. All TGFbeta isoforms increased slightly during pregnancy, reached highest expression during development, and returned to neonatal levels in adulthood. TGFbetaRI and TGFbetaRII patterns were similar to TGFbeta2 and TGFbeta1 respectively, whereas TGFbetaRIII expression was lowest at the postnatal time points. VEGF(164) and VEGF(120) showed a steady increase up to 2 weeks and declined at 12 weeks, whereas highest VEGF(188) expression occurred at 12 weeks. VEGF-A receptors expression paralleled the summation of all three isoforms, increasing steadily with age. CONCLUSION: Expression of growth factors in the developing lung is characterized by highly regulated distinctive patterns that may be critical to understand the early origin and progression of pulmonary diseases in childhood as well as in adulthood. Quantitative real-time PCR analysis revealed several differences compared to previously reported expression patterns defined with older methodologies.     

肛门直肠畸形胎鼠直肠末端Gli2、BMP4基因的表达

目的探讨乙烯硫脲（ETU）致畸胎鼠直肠末端Gli2、BMP4基因在胎鼠直肠肛门及其畸形发生过程中的表达和作用。方法取妊娠SD大鼠30只,按受孕时间配对分成2组,实验组（n=15）于孕10d灌胃注入10g／LETU （125mg／kg）,对照组n=15）予等量蒸馏水。两组分别于孕13d、14d、15d、16d和17d剖宫取胎鼠直肠末端1cm提取RNA,采用RT—PCR和RealtimePCR法检测Gli2、BMP4基因在直肠肛门发育不同时期的表达情况。结果采用RT-PCR法检测Gli2、BMP4基冈在直肠肛门发育不同时期的表达情况．发现在胎鼠第13～17天,实验组直肠末端Gli2、BMP4mRNA的表达水平均明显低于正常胎鼠直肠末端（P〈0．05）。而Realtime PCR检测Gli2、BMP4mRNA表达时,发现实验组Gli2的表达在胚胎第13天、第14天、第15天分别为（0．73＋0．07、0．60＋0．09、0．81＋0．06）,勺对照组相比显著降低（P〈0．05）,而在孕第16天、第17天实验组Gli2表达比对照组虽有下降,但无统计学意义;实验组BMP4的表达在孕第3～17天均较对照组下降,差异有统计学意义。结论直肠肛门的正常发育需要Shh信号通路的正常表达,Shh信号通路中转录因子Gli2和靶基囚BMP4的异常表达在肛门直肠畸形发生过程中起重要作用,ETU可能影响Shh信号转导通路和肛门直肠畸形发生。     

乙烯硫脲致畸胎鼠直肠末端Gli2基因的表达

目的　探讨乙烯硫脲致畸胎鼠直肠末端sonichedgehog(Shh)基因转录因子Gli2基因表达水平。方法　妊娠Wistar大鼠 2 4只随机分成 2组 ,实验组 (n =12 )在孕 11、13d分别给予 1%乙烯硫脲 (12 5mg/kg)胃管注入 ,对照组 (n =12 )予等量蒸馏水。孕 16d处死母鼠 ,实验组每只母鼠取 4只体质量相似的无肛畸形胎鼠 ,对照组取 4只体质量相似正常胎鼠 ,各取其直肠末端 1cm提取RNA ,采用RT PCR法检测Gli2基因表达 ,比较两组之间Gli2基因表达水平。结果　先天性无肛胎鼠直肠末端Gli2基因表达水平明显低于正常胎鼠直肠末端 (P =0 .0 0 4)。结论　Gli2基因表达水平减低与先天性无肛畸形的发生密切相关 ,乙烯硫脲致畸机制之一是影响Shh信号转导系统。