不同培养条件对猪卵母细胞IVM、IVF的影响

通过优化猪卵母细胞体外成熟、体外受精和胚胎体外发育体系,以进一步提高体外胚胎的生产效率和质量.研究了激素存在时间、不同激素和不同血清对猪卵母细胞体外成熟的影响;共培养体系、精卵作用时间、去除卵丘细胞的方法对猪体外受精及早期胚胎发育的影响.猪卵母细胞IVM培养48h,前24h内加入PMSG、hCG,后24h将其去除,卵母细胞总成熟率为79.54%;培养液添加15?S或15%NCS,卵母细胞成熟率分别为79.48%和74.81%;PMSG、HCG和E2配合使用后卵母细胞成熟率为81.42%.在IVF前用吹打法获得的卵裂率、桑椹胚率分别为37.89%和8.54%,精卵共孵育6h或8h的卵裂率(40.52%,37.24%)、桑椹胚率(8.42%,7.85%),以及用输卵管上皮细胞共培养所获得的卵裂率(40.84%)、桑椹胚率(9.53%)均显著高于其它各组.     

早期人胚胎cDNA文库构建及目的基因筛选

收集受精后３、４和５周龄药物流产胚胎,用改良一步法提取总ＲＮＡ,ｏｌｉｇｏ（ｄＴ）纤维素柱纯化ｍＲＮＡ,逆转录合成一链ｃＤＮＡ,完成二链ｃＤＮＡ的合成后,经碱变性电泳检测,合成ｃＤＮＡ的大小为０．４～９．０ｋｂ之间,且主要集中在１．０～２．０ｋｂ。除去多余的接头,收集大于４００ｂｐ的ｃＤＮＡ片段,与载体ｐＳＰＯＲＴ１和和γＺｉｐＬｏｘ连接,分别得到３、４、５周龄人胚胎质粒文加和噬菌体文库。另外,采     

药用植物栀子的组织培养

栀子(Gardenia jasminoides)为药用木本植物。以栀子果皮、种子团和种子为外植体,研究不同激素配比及不同培养方式对愈伤组织诱导和芽分化的影响。研究结果表明,培养基成分为MS+0.5 mg·L–12,4-D+0.25 mg·L–16-BA较适宜果皮和种子愈伤组织的诱导,诱导率分别为83.3%和88.5%;培养基成分为MS+1.0 mg·L–12,4-D+1.0 mg·L–16-BA较适宜种子团愈伤组织的诱导,诱导率为78.1%。3种外植体诱导的愈伤组织中,只有种子愈伤组织能通过液体培养分化出芽;TDZ对芽分化有明显的促进作用;最佳的芽分化培养基为MS+0.05 mg·L–1NAA+0.10 mg·L–1TDZ,其愈伤组织分化率为8.75%。该研究以栀子种子为外植体,并获得了再生植株,为药用植物栀子转基因体系的建立奠定了基础。     

Microbial 2,3-butanediol production: a state-of-the-art review

2,3-Butanediol is a promising bulk chemical due to its extensive industry applications. The state-of-the-art nature of microbial 2,3-butanediol production is reviewed in this paper. Various strategies for efficient and economical microbial 2,3-butanediol production, including strain improvement, substrate alternation, and process development, are reviewed and compared with regard to their pros and cons. This review also summarizes value added derivatives of biologically produced 2,3-butanediol and different strategies for downstream processing. The future prospects of microbial 2,3-butanediol production are discussed in light of the current progress, challenges, and trends in this field. Guidelines for future studies are also proposed.     

A combined A431 cell membrane chromatography and online high performance liquid chromatography/mass spectrometry method for screening compounds from total alkaloid of Radix Caulophylli acting on the human EGFR

We have developed an online analytical method that combines A431 cell membrane chromatography (A431/CMC) with high performance liquid chromatography and mass spectrometry (LC/MS) for identifying active components from Radix Caulophylli acting on human EGFR. Retention fractions on A431/CMC model were captured onto an enrichment column and the components were directly analyzed by combining a 10-port column switcher with an LC/MS system for separation and preliminary identification. Using Sorafenib tosylate as a positive control, taspine and caulophine from Radix Caulophylli were identified as the active molecules which could act on the EGFR. This A431/CMC-online-LC/MS method can be applied for screening active components acting on EGFR from traditional Chinese medicines exemplified by Radix Caulophylli and will be of great utility in drug discovery using natural medicinal herbs as a source of novel compounds.     

大型绿藻浒苔转化表达系统选择标记的筛选

主要研究了条浒苔对抗生素氯霉素和除草剂Basta的敏感性,以确定适合的阳性选择标记基因。应用不同浓度氯霉素(0、25、50、75、100、125μg/ml)和Basta(0、5、12.5、25、37.5、50μg/ml)对不同发育时期条浒苔细胞存活率影响进行了测定。实验结果表明:不同发育时期条浒苔对氯霉素和Basta的敏感性不同。其中最大浓度125μg/ml浓度的氯霉素在15d内对条浒苔孢子和小苗两个不同发育时期的细胞均难以达到全部杀死效果,相对存活率仍分别为1%和20%;而Basta对条浒苔孢子和小苗均具有很强的杀生作用,其中5μg/ml浓度的Basta在3d内可将条浒苔孢子全部杀死,12.5μg/ml浓度下约一周时间可以将浒苔小苗全部致死。本实验结果提示bar基因有可能成为浒苔基因工程较理想的选择标记基因。     

Phenotypic characterization of the Xenorhabdus bacterial symbiont of a Texas strain of the entomopathogenic nematode Steinernema riobrave, and characterization of the Xenorhabdus bovienii bacterial symbiont of a Newfoundland strain of Steinernema feltiae

Two bacterial symbionts of entomopathogenic nematodes, one of which originated from Texas, U.S.A., and the other from Newfoundland, Canada, were characterized phenotypically. These strains belonged to the genus Xenorhabdus. The Newfoundland (NF) strain was shown to be X. bovienii but the Texas (TX) strain was not identified at the species level. Four additional cultures of Xenorhabdus were included in the study. These were a strain of X. bovienii (Ume?), which was from a nematode of European origin, and strains of X. nematophilus, X. beddingii, and X. poinarii. The tests used in this study indicated identical properties for the NF (North American) and Ume? (European) strains of X. bovienii. These could be differentiated from the other strains studied by their failure to grow at 34 degrees C and resistance to low concentrations of a mixture of amoxilline and clavulanic acid. The Xenorhabdus TX strain could be differentiated from the other strains studied by its failure to grow at 10 degrees C. Of the tests done, approximately 30 were useful in distinguishing between the strains and species studied.     

Identification of salt-stress responsive genes in rice (Oryza sativa L.) by cDNA array

To identify salt stress-responsive genes, we constructed a cDNA library with the salttolerant rice cultivar, Lansheng. About 15000 plasmids were extracted and dotted on filters with Biomeck 2000 HDRT system or by hand. Thirty genes were identified to display altered expression levels responding to 150 mmol/L NaCl. Among them eighteen genes were up-regulated and the remainders downregulated. Twenty-seven genes have their homologous genes in GenBank Databases. The expression of twelve genes was studied by Northern analysis. Based on the functions, these genes can be classified into five categories, including photosynthesis-related gene, transportrelated gene, metabolismrelated gene, stress-or resistancerelated gene and the others with various functions. The results showed that salt stress influenced many aspects of rice growth. Some of these genes may play important roles in plant salt tolerance.     

ITE and TCDD Differentially Regulate the Vascular Remodeling of Rat Placenta via the Activation of AhR

Vascular remodeling in the placenta is essential for normal fetal development. The previous studies have demonstrated that in utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, an environmental toxicant) induces the intrauterine fetal death in many species via the activation of aryl hydrocarbon receptor (AhR). In the current study, we compared the effects of 2-(1′H-indole-3′-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) and TCDD on the vascular remodeling of rat placentas. Pregnant rats on gestational day (GD) 15 were randomly assigned into 5 groups, and were exposed to a single dose of 1.6 and 8.0 mg/kg body weight (bw) ITE, 1.6 and 8.0 µg/kg bw TCDD, or an equivalent volume of the vehicle, respectively. The dams were sacrificed on GD20 and the placental tissues were gathered. The intrauterine fetal death was observed only in 8.0 µg/kg bw TCDD-exposed group and no significant difference was seen in either the placental weight or the fetal weight among all these groups. The immunohistochemical and histological analyses revealed that as compared with the vehicle-control, TCDD, but not ITE, suppressed the placental vascular remodeling, including reduced the ratio of the placental labyrinth zone to the basal zone thickness (at least 0.71 fold of control), inhibited the maternal sinusoids dilation and thickened the trophoblastic septa. However, no marked difference was observed in the density of fetal capillaries in the labyrinth zone among these groups, although significant differences were detected in the expression of angiogenic growth factors between ITE and TCDD-exposed groups, especially Angiopoietin-2 (Ang-2), Endoglin, Interferon-γ (IFN-γ) and placenta growth factor (PIGF). These results suggest ITE and TCDD differentially regulate the vascular remodeling of rat placentas, as well as the expression of angiogenic factors and their receptors, which in turn may alter the blood flow in the late gestation and partially resulted in intrauterine fetal death.