不同贮藏年限老芒麦种胚线粒体抗氧化功能的变化规律

种子在自然贮藏过程中常常伴随着内部生理机能的恶化，线粒体作为种子内活性氧（reactive oxide species，ROS）产生的主要位点是最先遭到破坏的细胞器。为探讨不同贮藏年限对老芒麦种胚线粒体抗氧化功能的影响，本试验以室温贮藏0～4年的老芒麦种子为材料，分析比较其老化规律及种胚线粒体抗氧化特性的变化规律。结果表明：随着贮藏年限的延长，老芒麦种子发芽势、发芽率和种苗鲜重逐渐下降，死种子逐渐增多，种胚线粒体苹果酸脱氢酶（mitochondria malate dehydrogenase，MDH）、谷胱甘肽还原酶（glutathione reductase，GR）、单脱氢抗坏血酸还原酶（monodehydroascorbate reductase，MDHAR）活性逐渐下降，但在死种子中超氧化物歧化酶（superoxide dismutase，SOD）活性显著升高。此外，在贮藏过程中老芒麦种胚线粒体O₂^·-产生速率不断上升，而H₂O₂含量则呈现逐渐降低的趋势，表明线粒体中O₂^·-的积累与细胞氧化损伤密切相关。     

猪胚胎干细胞的分离克隆

本文从分化抑制物、培养基的选择内细胞团的分离,胚胎干细胞的分离及鉴定方法等方面系统地综述了猪胚胎干细胞分离克隆的研究进展;并对其未来的应用前景进行展望。     

长寿花胚性愈伤组织的诱导及胚状体再生

 研究了长寿花胚性愈伤组织的筛选，胚状体的诱导发生、发育过程及植株再生。经过对外观及细胞学观察，看出外观质地疏松、颗粒状的淡黄色愈伤组织细胞圆形且形状规则，是胚性愈伤组织。诱导胚性愈伤组织的最适培养基为：MS+2，4-D 2 mg·L^-1 +BA 0.2 mg·L^-1；胚状体的诱导培养基为MS+BA 2 mg·L^-1 +NAA 0.2 mg·L^-1 +活性炭4 g·L^-1+蔗糖30 g·L^-1，胚状体诱导率可达185个胚状体；胚状体的再生培养基为MS+蔗糖30 g·L^-1。利用石蜡切片对胚状体的发生过程进行了观察。     

Comparison of different conditions inducing embryonic stem cells

AIM: To evaluate the different conditions inducing mouse embryonic stem cells (ESC) in vitro to differentiate into cardiomyocytes. METHODS: BRL conditioned medium was used to promote the growth of ESC and maintain them in an undifferentiated state. During the inducing process, retinoic acid (RA), DMSO, activin-A and TGF-β₁ were used as inducing reagents, and made up six kinds of differentiating medium. Then a three-step method inducing ESC cultured in hanging drops, in suspension and in plating was used to induce the differentiation of ESC. RESULTS: ESC were induced in vitro to differentiate into cardiomyocytes. Of all groups, the highest differentiating rate was observed in the group induced by activin-A (20 μg/L) and TGF-β₁ (2 μg/L). CONCLUSION: The inducing conditions including activin-A (20 μg/L) and TGF-β₁ (2 μg/L) is very valuable in inducing ESC differentiation into cardiomyocytes.     

新疆灌溉农业发展与节水潜力分析

分析了新疆灌溉农业的大发展及取得的成就，针对经济社会可持续发展对水资源有续利用的客观要求，对农业灌区的节水现状进行了探讨，并从地表水资源可利用量、输水系统节水潜力、平原水库增蓄水潜力及田间灌溉节水潜力等方面对灌溉用水的节水潜力问题进行了较全面的分析和研究。     

Construction of mouse ESC line stably expressing Pdx1 by Tet-On system

AIM To construct the mouse embryonic stem cell （ESC） line with stable pancreatic and duodenal homeobox 1 （Pdx1） expression by Tet-On system, which may lay a foundation for further research on the differentiation of Pdx1⁺ definitive endoderm cells into pancreatic cells. METHODS The Pdx1-overexpressing lentiviral vector with green fluorescent protein marker and puromycin resistance was constructed by Tet-On system and was used to infect the mouse ESC. The cells were divided into 3 groups： blank control group （ESC group）, empty lentivirus control group （PDX1^- ESC group） and Pdx1 lentivirus transfection group （PDX1⁺ ESC group）. Flow cytometry was used to detect the transfected cells after screening by doxycycline （DOX）. The function of Tet-On system and the expression of Pdx1 gene were detected. The transfected cells in PDX1^- ESC group and PDX1⁺ ESC group were sorted by flow cytometry, and constructed ESC line with stable expression of Pdx1 and negative control ESC line were verified. RESULTS （1） The positive rates of transfected cells in PDX1^- ESC group and PDX1⁺ ESC group were 90.72% and 94.01% after screening by DOX, respectively. The positive rates of transfected cells in PDX1^- ESC group and PDX1⁺ ESC group was 97.84% and 98.13% after sorting by flow cytometry, respectively. （2） With DOX, green fluorescence was observed in PDX1^- ESC group and PDX1⁺ ESC group. The mRNA and protein expression of Pdx1 was significantly increased in PDX1⁺ ESC group （P<0.05）. Without DOX, no green fluorescence was observed in the cells of the 3 groups, and no significant difference in the mRNA and protein expression of Pdx1 was observed （P>0.05）. （3） After 3 months of cryopreservation, the cell lines still survived in resuscitation culture and were regulated by DOX. CONCLUSION Using Tet-On system, the mouse ESC line with inducible Pdx1 expression were successfully established and could be used as an effective cell model to research the differentiation of Pdx1⁺ definitive endoderm cells into pancreatic cells.     

两种激活处理促进小鼠孤雌胚胎原核形成

不同人工处理方法激活哺乳动物卵母细胞的机理相似,但其激活效率存在差异。本研究以昆明（KM）、129/Sv×KM F1和C3H×KM F1雌鼠来源的卵母细胞为对象,利用氯化锶（SrCl2,Sr2＋）联合细胞松弛素B（cytochalasin B,CB）（Sr2＋＋CB）和离子霉素（ionomycin,Ion）联合6-二甲胺基嘌呤（6-dimethylaminopurine,6-DMAP）（Ion＋6-DMAP）两种激活方法处理下对比分析不同品系小鼠卵母细胞的激活效率,并以卵母细胞原核形成率、原核数量和孤雌胚胎体外发育来评价两种激活剂的激活效率。研究结果表明,Ion＋6-DMAP激活卵的1原核比率显著高于2原核（p〈0.05）,Sr2＋＋CB激活卵的2原核比率显著高于1原核（p〈0.05）;KM、129/Sv×KM F1和C3H×KM F1各组孤雌胚胎卵裂率和激活率没有显著差异（P〉0.05）,但129/Sv×KM F1和C3H×KM F1囊胚发育率显著高于KM组（p〈0.05）。3种小鼠品系的卵母细胞用Sr2＋＋CB处理的孤雌胚胎发育率显著高于Ion＋6-DMAP。结果证明,Sr2＋＋CB处理小鼠卵母细胞的激活效率明显优于Ion＋6-DMAP;129/Sv×KM F1和C3H×KM F1的孤雌胚胎体外发育率显著高于KM小鼠,为研究小鼠遗传背景影响孤雌胚胎发育的机理提供参考。     

改良大豆胚尖再生体系的研究

为了研究利用Thidiazuron(TDZ)建立大豆胚尖高效再生体系的可行性。跃进10号的成熟种子浸泡16 h后,收集胚尖转入添加了不同浓度的TDZ芽诱导培养基中,4周后计算出芽率,并对拔高培养基和生根培养基进行优化。TDZ浓度为0.08 mg/L时,出芽率最高,达92.6%,平均每个外植体产生的丛生芽的数目也最多。适宜大豆胚尖的芽诱导分化培养基为MS+0.08 mg/L TDZ,拔高培养基为MS+2.0 mg/L KT+0.2 mg/L NNN,生根培养基为1/2MS+1.0 mg/L IBA。利用TDZ建立大豆胚尖高效再生体系是可行的,提高了丛生芽的分化率,为快繁和提高遗传转化效率奠定了坚实的基础。     

鳗鲡（Anguilla japonica）胚胎发育与水温和盐度的关系

实验结果表明，鳗鲡胚胎发育与水温和盐度关系密切，在一定的水温范围内，胚胎发育所需时间与水温呈负相关关系，ｙ＝２４６．７７５ｅ＾－０．０８２ｘ。其合适水温范围是２０－２６℃，临界水温上限３０℃，下限１６℃；胚胎发育的合适盐度范围是１５－３５‰，临界盐度上限４０－４５‰，下限５－１０‰。胚胎孵化率与盐度呈二次曲线相关关系，ｙ＝３６．９３＋０．２３ｘ－０．１９ｘ＾２。     

Optimal conditions for egg storage, incubation and post-hatching growth for the freshwater turtle, Chelodina rugosa: Science in support of an indigenous enterprise

Incubation of northern snake-necked turtle (Chelodina rugosa) eggs and subsequent sale of hatchlings for the pet industry has the potential to provide culturally suitable employment for indigenous communities in northern Australia. Developmental arrest in response to egg inundation is unique to C. rugosa. Eggs can be stored under water for up to 10 weeks without appreciable impact on egg or embryo survival, allowing the transport and sale of eggs into niche markets without high levels of mortality, and permitting eggs to accumulate in diapause until there are sufficient numbers to incubate as batches. Eggs that are not inundated or inundated for short periods experience similar survival rates to eggs inundated for lengthy periods. Incubation temperature influences embryo survival and development period in C. rugosa. Embryonic survival is greatest at 26 °C, steadily declining as temperature increases to 32 °C. A similar increase in incubation temperature decreases incubation period by approximately 40 days, however almost half of this variation is attributed to the increase in incubation temperature from 26 to 28 °C. Hatchling growth in C. rugosa is characterized by two phases. There is an initial phase of relatively slow growth under the partial influence of initial egg size and incubation duration, followed by a second phase of relatively rapid growth under the partial influence of water temperature and mass at hatching. Post-hatching survival is negatively correlated with duration of egg inundation and water temperature. Evidence suggests that inundation of C. rugosa eggs for 6 weeks, incubation of embryos at 28 °C and raising hatchlings in 28 °C water will yield the best overall outcomes.