利用辐射与杂交相结合创造小麦优异新种质的研究

利用辐射诱变与杂交育种相结合的方法选育出豫同843等11个小麦优异突变体。介绍了这些突变体的来源、特征特性及应用价值,总结了该方方法在创造小麦新种质方面的经验。     

Microscopic and ultramicroscopic localizations and quantitative analysis of 5-HT receptors in human placentas

The localizations of 5-hydroxytryptamine receptor (5-HTR) at light and electron microscopic levels and its quantitative analysis in human placentas were studied by using immunohistochemistry and in situ hybridization. Both syncytiotrophoblast and cytotrophoblast in placental villi and fetal white blood cells in villose capillary cavity showed 5-HT receptor immunoreactivity, with 5-HT 1A receptor mRNA hybridized signal detected in cytoplasm. But the stromal cells and capillary endothelium in placental villi showed 5-HT receptor immunoreactivity in cytoplasm, without 5_HT\-1A receptor mRNA hybridized signal detected. This suggested that two layers of trophoblast cells may produce 5-HT 1 and 5-HT 2 receptors, that the stromal cells and capillary endothelium in placental villi may only produce 5-HT 2 receptor. By immunohistochemistry at electron microscopic level, the small flattened vesicles and large dense cored vesicle within trophoblast cells showed 5-HT receptor immunoreactivity. This suggested that it may be the result of 5-HT receptors internalization and transportion. Using a quantitative immunohistochemical method, the contents of 5-HT receptor in placenta were higher during the 6th week of gestation, and decreased in 7th and 8th, reoccurred the second peak in the 9th, reduced gradually during the 10th, 20th and 40th of the gestation period. These changes paralleled the contents of 5-HT in the authors' studies, reflecting that 5-HT may be one of the most important bioactive substances in placental self-regulation.     

Physical location of the ricePi-5(t), Glh andRTSV genes by ISH of BAC clones

Mapping of low or single-copy sequences on plant chromosomes has proven difficult because of very low frequency of signal detection. Rice BAC library is being used widely in rice genome research due to its distinctive advantages over other library systems. In this study, two biotin-labeled rice BAC clones closely linked to a rice blast resistance, green leafhopper resistance and tungro spherical virus resistance gene,Pi-5(t), Glh, RTSV, werein situ hybridized to rice chromosomes. They were located on the long arm and short arm of chromosome 4 with FL value of 40% and 100% respectively. The frequency of signal detection reached 46.8% and 59.2%. The signal location were consistent with the selective marker on rice saturated molecular map. The results demonstrated the advantages to locate BAC clones to chromosomes byin situ hybridization and will facilitate the rice low or single-copy gene location by using the BAC library. Supported by the National Natural Science Foundation of China and the Doctorate Vesting Point Foundation of the Education Department of the People's Republic of China Yan Huimin: born in 1964, Lecturer     

青鳉鱼早期胚胎中外源DNA的复制行为的研究

利用显微注射技术将外源ＤＮＡ与标有生物素的ｄＡＴＰ一起导入处于１细胞期的青鱼（Ｍｅｄａｋａ）受精卵细胞质中，鱼卵在２５℃孵化一天至胚孔封闭期，从胚胎细胞质中提取ＤＮＡ，经分子杂交发现外源ＤＮＡ在胚胎中可进行复制。ＤＮＡ样品再经核酸电镜分析，发现了几种类型的复制分子，并发现多复制叉及成熟前复制现象。由此认为外源ＤＮＡ可以多种方式在青鱼早期胚胎细胞质中进行复制。     

环境微生物的分子生物学研究方法

本文介绍了在环境微生物生态研究中的分子生物学方法如分子杂交，聚合链式扩增技术PC震，rRNA基因同源分析法，新型凝胶电泳技术，生物醌谱图法等和应用。这些技术的使用将大大扩展微生物生态学研究的空间，并使得在分子水平研究生态问题的机制成为可能。