HOMEO BOX GENES IN NON-SEGMENTED ECHINODERMS

将通过分子克隆研究海胆含同源盒基因 以及基因组DNA和cDNA的DNA核苷酸测序。 初始 基因组DNA克隆的选择将基于它们与 果蝇同源盒探针。 这些序列和氨基酸序列 将它们编码的序列与其他物种的序列进行比较， 进化关系;它也将确定是否克隆 基因是相连的。 基因组DNA和cDNA序列将与 阐明转录单位的结构。 的活性 海胆卵母细胞、卵、胚胎和成体组织中的转录单位 将通过探测RNA凝胶转移与克隆 序列的 转录本将被定位在胚胎的组织切片中 通过原位杂交。 蛋白质产物将整体定位 胚胎免疫荧光显微镜使用抗体探针。 自海 海胆是明显的非分割，分析这些发展 海胆中的控制基因将提供一个信息对比， 目前正在研究的其他生物的数据，并可能建立一个 更好地理解homeo box的更一般的功能， 基因在调节位置信息的转导或 细胞命运的确定与建立 同色异谱 人们无法准确预测这些实验的医学意义。 当我们了解基因调控的方式时，我们就有希望 使用此信息来纠正过程中的任何紊乱。 为 poly（A）尾的发现为分离mRNA提供了一种工具， 同源异型盒的发现是否为分离基因提供了一种工具 调节其他基因的表达。 进一步发展中 用于研究基因表达和检查的体内和体外系统 正常或突变的同源异型RNA对这些系统的影响 有一天，含有基因的蛋白质产物可能会使人们有可能 纠正人类发育障碍。 基因表达的调控 也是癌症生物学的中心问题。

Sea urchin homeo box-containing genes will be studied by molecular cloning and DNA nucleotide sequencing of both genomic DNA and cDNA. The initial selection of the genomic DNA clones will be based on their homology to Drosophila homeo box probes. These sequences and the amino acid sequences they encode will be compared to sequences from other species to infer evolutionary relationships; it will also be determined whether the cloned genes are linked. The genomic DNA and cDNA sequences will be compared to elucidate the structure of the transcription units. The activity of the transcription units in sea urchin oocytes, eggs, embryos and adult tissues will be investigated by probing RNA gel transfers with the cloned sequences. The transcripts will be localized in tissue sections of embryos by in situ hybridization. The protein products will be localized in whole embryos by immunofluorescence microscopy using antibody probes. Since sea urchins are distinctly non-segmented, an analysis of these development controlling genes in sea urchins will provide an informative contrast to the data from the other organisms currently under study and may establish a better understanding of the more general functions of homeo box-containing genes in regulating the transduction of positional information or the determination of cell fate versus the limited function of establishing metamerism. One cannot predict exactly the medical significance of these experiments. When we understand the manner in which genes are regulated, we can hope to use this information to correct any disorders in the process. As the discovery of poly(A) tails has provided a tool for isolating mRNA, so too may the discovery of homeo boxes have provided a tool for isolating genes which regulate the expression of other genes. Further development of in vivo and in vitro systems for studying gene expression and an examination of the effects on these systems caused by normal or mutated homeo box-containing gene protein products may one day make it possible to correct human developmental disorders. The regulation of gene expression is also a central problem in cancer biology.