Role of kisspeptin/GPR54 signaling pathways in prompting formation of precocious puberty

AIM: To explore the role of kisspeptin/GPR54 signaling pathway in the pathogenesis of precocious puberty based on female precocious puberty rat model induced by the single dose of danazol. METHODS: Female SD rats aged 3 d were randomly divided into normal group, vehicle group and model group. On the 5th day, the model rats were given a single subcutaneous injection of danazol with ethanol and ethylene glycol mixture. All rats were executed on 15 d, 25 d, 30 d, 35 d and 40 d, and the samples were collected to observe the sexual organ development. The levels of E₂, FSH and LH in peripheral blood were measured by ELISA. The Kiss-1 mRNA expression of Kiss-1, GPR54 and GnRH in hypothalamus was detected by real-time PCR. The kisspeptin expression in rat hypothalamus was observed by immunofluorescence. RESULTS: The time for puberty onset and sexual maturation in the model rats was significantly earlier than that in normal group and vehicle group. On days 25 and 30, the levels of peripheral sex hormones and uterine coefficients in model group were significantly higher than those in normal group and vehicle group. On days 25 and 30, the ovarian morphological development in the model rats was significantly earlier than that in normal group. On day 25, the mRNA expression of hypothalamic Kiss-1 and GnRH, and kisspeptin expression of hypothalamic arcuate nucleus in the model rats significantly increased compared with normal group and vehicle group. On day 30, kisspeptin expression of hypothalamic arcuate nucleus in the model rats decreased compared with normal group and vehicle group. On day 35, the mRNA expression of Kiss-1 and GnRH in the model rats decreased compared with normal group and vehicle group. The mRNA expression of GPR54 had no obvious difference among all groups. CONCLUSION: The Kiss-1 mRNA and kisspeptin expression in the model rats with precocious puberty is significantly increased in the hypothalamus during onset of puberty, suggesting that kisspeptin is an initiating factor for precocious puberty. Kisspeptin/GPR54 signaling pathway may play an important role in the occurrence of precocious puberty.     

籽瓜不同生育期不同部位总黄酮和总皂苷含量测定

以籽瓜为试材,分别以芦丁和葫芦素B为标准品,采用亚硝酸钠-硝酸铝显色法和香草醛-硫酸比色法分别测定籽瓜中总黄酮和总皂苷含量,为籽瓜质量控制提供科学依据。结果表明:总黄酮线性方程为Y=0.0059C-0.0081,R2=0.9994;总皂苷线性方程为Y=0.005C-0.0335,R2=0.9991。数据表明这2种测定方法准确,且重复性好。籽瓜不同部位的总黄酮和总皂苷含量分别在这2种方法下随生长时期变化而变化,根据这些数据可以为籽瓜的综合开发利用提供参考依据。     

DPC与DTA-6复配对转基因抗虫棉苗期生长发育的调控

无论浸种还是叶面喷施,与单独使用DPC相比,DPC与DTA6复配在促进转基因抗虫棉幼苗根长和侧根原基增加的同时,显著减弱了DPC对地上部生长的延缓作用,中棉所30下胚轴长度较对照仅缩短3%左右,中棉所30、新棉99B和sGK321的苗期叶面积均相当于对照的93%～94%,这可能与复配调节剂处理后转基因抗虫棉幼苗各部位的IAA浓度较DPC单独处理明显提高有关。DPC与DTA6复配还可显著增加转基因抗虫棉苗期功能叶叶绿体的基粒类囊体垛叠程度,提高光合作用。     

牛GDF-9基因的克隆与组织表达的分析

为了检测牛GDF-9基因mRNA在怀孕期牛生殖系统的表达情况,为GDF-9基因在雌性动物繁殖上的研究提供一定的理论依据。本试验根据GenBank中报道的牛GDF-9基因序列设计引物,从牛卵巢、输卵管、子宫、肾脏中提取RNA,采用RT-PCR技术进行cDNA扩增,扩增产物与载体pGM-T连接,转化大肠杆菌DH5α,筛选阳性克隆,测序。结果表明,已成功克隆的阳性重组子经测序鉴定其片段大小与预期大小完全一致,为264 bp。序列同源性分析比较表明,该cDNA及其推导的氨基酸序列与绵羊GDF-9cDNA和氨基酸序列同源性分别为97%和94%。以-βactin为内参照物,采用RT-PCR技术进行半定量分析,通过检测比较牛GDF-9基因在卵巢、输卵管、子宫、肾脏组织中mRNA的表达情况。结果表明,牛GDF-9基因在卵巢中表达量最高,在输卵管、子宫、肾脏中均有表达,但表达量不高。     

水稻新品种松粳6号的引进与推广

松粳6号是兴安盟农业科学研究所2001年从黑龙江省农科院第二水稻研究所引进的优质水稻新品种.该品种具有抗病性强、分蘖力强、米质优、产量高、适应性强、活秆成熟等特点,通过4年的试验、示范,适宜在兴安盟地区2550～2650℃积温区大面积推广应用,对水稻品种更新换代做出了重大贡献.     

四川不同生态区高产栽培条件下的杂交籼稻的稻米品质

郫县、汉源、射洪、邻水是四川具代表性的4个生态区,郫县位于成都平原区,土壤肥沃但受弱光限制;汉源位于攀西高海拔地区,温光充足;射洪位于川中丘陵区,受地形制约而气温日差较小;邻水则位于川东丘陵区,水资源缺乏且受干旱等灾害制约。本文以位于这4个典型生态区实施的水稻高产示范片为研究对象,分别对4个生态区及各生态区不同栽培方式、不同高产水平的杂交籼稻稻米碾米品质、外观品质、蛋白质含量、直链淀粉含量及淀粉RVA谱特征值进行比较研究。结果表明:(1)生态条件与稻米品质有密切关系,受气温和土壤肥力影响较大,郫县的稻米品质最优,邻水相对较劣;齐穗前后气温略高及较高的土壤全氮、全钾、速效磷含量有利于高碾米品质的形成;土壤全磷含量的降低可显著增加米粒长宽比;灌浆成熟期的高温会增加稻米的垩白粒率和垩白度,而土壤速效磷含量高则有利于降低垩白粒率和垩白度;灌浆结实期的高温也会降低稻米蛋白质含量;直链淀粉含量随土壤有机质含量的升高而升高;峰值黏度与土壤全钾含量显著负相关,崩解值与土壤全钾、速效磷显著负相关,还与齐穗前8~21 d的日最高气温显著正相关,回复值、峰值时间与齐穗前14~21 d日最高气温、抽穗至成熟期日最高气温呈显著或极显著负相关,与土壤碱解氮呈显著正相关。(2)各栽培方式间,机直播的碾米品质较优,优化定抛的直链淀粉含量较高,而机插的峰值黏度、崩解值较高,消减值较低,蒸煮食味品质较好。(3)高产及超高产田块的碾米品质整体较优,而外观品质和蒸煮食味品质相对较差。本研究可为四川杂交中籼稻高产优质栽培技术提供理论参考。     

应用型大学转型背景下食品工程实践类课程多元化评价体系

应用型大学转型是当前许多地方性本科院校办学的重要发展方向.在此背景下,优化食品工程实践类课程的考核评价体系,可以有效提高食品工程实践类课程的培养效率,增加食品专业毕业生的就业竞争力.     

Application of Swimming Pool Heating with Solar Energy

Solar energy sourcei s regenerative source,reasonable use of it is an effective way to solve the problem of exiguousness of the traditional energy. But the usage of the solar energy is limited. To achieve the satisfactory effect, we must use a reasonable system style combined with the traditional energy. Through the application of swimming pool heating with solar energy. It is pointed out that more attention should be puid to reason dispose the collectors,store up heating tank,assistant thermal resource and dependable auto control. Solar energy can take place of the traditional energy, it is obviously that the solar energy can save the money and the energy and protect the environment.     

棉花黄萎病菌分子生物学研究新进展

本文以分子生物学研究手段为纲 ,从RFLP、RAPD、ITS等方面 ,综述了国内外在棉花黄萎病菌种内划分及致病力分化上的研究状况及最新进展     

基于ISTA标准的种苗评价专家系统

文章阐述了种苗评价专家系统知识库的体系结构，介绍了事实知识数据库的设计方法和系统的推理方式，开发了一种基于Windows平台通用的种苗评价专家系统单机版应用软件——ESSE，该软件对系统配置要求低，界面友好，功能丰富，非常适合我国各地的种子站、种子公司以及互联网覆盖不发达的广大农村地区使用。