BIOCHEMISTRY OF EARLY MAMMALIAN DEVELOPMENT

影响哺乳动物胚胎发育的两种遗传异常将是 调查过了。少指指(Os)和显性黄(Ay)都是 杂合子形式的突变会导致发育异常 而纯合子形式会导致早期胚胎死亡。自Ay以来 突变似乎与生态嗜好病毒的插入有关， 这种突变的分子基础将使用探针进行研究 针对Ay相关的前病毒整合位点和侧翼开发 宿主DNA序列。刺鼠轨迹的正常mRNA转录本将 在早期胚胎中进行鉴定，并评估突变的影响。 将制备Ay/Ay畸胎癌细胞系，且Ay/Ay等于+/+ 分析了嵌合体。纠正Ay/Ay细胞缺陷的研究 在+/+细胞中复制缺陷将通过显微注射 克隆的DNA。二丁酰cAMP对Ay/Ay胚胎发育能力的影响 将对体外孵化进行评估。两国之间的关系 Os的杂合子表现和发现的有丝分裂缺陷 将对OS/OS胚胎进行分析。OS/+卵细胞的细胞增殖 圆柱体和肢芽的测定，以及补钙的效果 电离机，A23187，经评估。

Two genetic abnormalities affecting mammalian embryonic development will be investigated. Oligosyndactyly (Os) and dominant yellow (Ay) are both mutations which in the heterozygous form cause developmental abnormalities and in the homozygous form cause early embryonic death. Since the Ay mutation appears to be associated with the insertion of an ecotropic virus, the molecular basis of this mutation will be studied using probes to be developed against the Ay-associated proviral integration site and flanking host DNA sequences. The normal mRNA transcripts of the agouti locus will be identified in early embryos and the effects of the mutation assessed. Ay/Ay teratocarcinoma cell lines will be prepared and Ay/Ay equal to +/+ chimeras analyzed. Studies to correct the defect in Ay/Ay cells and to reproduce the defect in +/+ cells will be undertaken by microinjection of cloned DNA. The effect of dibutyryl cAMP on the ability of Ay/Ay embryos to hatch in vitro will be assessed. The relationship between the heterozygous manifestations of Os and the mitotic defect identified in Os/Os embryos will be analyzed. Cellular proliferation in Os/+ egg cylinders and limb buds will be determined, and the effect of the calcium ionophone, A23187, assessed.