CHROMOSOME STRUCTURE DURING DROSOPHILA DEVELOPMENT

染色体是包含一种基因蓝图的DNA分子 有机体。保持染色体的结构完整性是必不可少的 所有真核生物的正常生长和分化。 染色体结构的异常是许多先天性 人类的异常和遗传性疾病。 关于真核生物的结构，仍然存在许多重要的问题 染色体。这项研究的长期目标是阐明 真核生物大规模同色-异色结构域结构 染色体，并确定这些结构域之间的相互作用如何 在发育过程中改变染色体结构。 一种小的、分子易处理的模型染色体，即1300kb的DP(1；f)1187 果蝇的微小染色体提供了一个独特的机会 以解决以前无法解决的关于染色体结构的问题。 初步研究已经证明，DP的限制性片段 (1；f)1187交叉等色-异色函数并扩展 具有极不寻常的性质，包括 在DNA印迹过程中选择性地保留在琼脂糖凝胶中 并经历改变碎片大小的结构变化。这些 不同组织的特性在数量和质量上都有所不同。这个 这项研究的具体目的将是扩大这些观察结果，并： 1)测定不同组织中DP(1；f)1187的结构 染色体结构包括多倍体、多线体、二倍体和单倍体 染色体； 2)通过表征来确定初始观察的概括性 正常染色体异染色区的性质 补码和 3)确定DP异常物理性质的分子基础 (1；f)1187异色DNA。 已经使用该系统进行的观测的新颖性表明 持续的分析将揭示DNA和 染色体结构具有广泛的意义。

Chromosomes are DNA molecules that contain the genetic blueprint of an organism. Maintaining the structural integrity of chromosomes is essential for the normal growth and differentiation of all eukaryotic organisms. Aberrations in chromosome structure are a hallmark of many congenital abnormalities and genetic diseases of humans. Many significant questions remain concerning the structure of eukaryotic chromosomes. The long-term objective of this research is to elucidate the large-scale euchromatic-heterochromatic domain structure of eukaryotic chromosomes, and determine how interactions between these domains can alter chromosome structure during development. A small, molecularly-tractable model chromosome, the 1300 kb Dp (1;f) 1187 mini chromosome of Drosophila melanogaster provides a unique opportunity to address previously inaccessible questions about chromosome structure. Initial studies have already demonstrated that restriction fragments of Dp (1;f) 1187 that cross euchromatic-heterochromatic functions and extend into heterochromatic domains have highly unusual properties including being selectively retained in agarose gels during DNA-blotting protocols and undergoing structural changes that alter fragment size. These properties vary between tissues both quantitatively and qualitatively. The specific aim of this research will be to extend these observations and: 1) determine the structure of Dp (1;f) 1187 in tissues of differing chromosome structure including polyploid, polytene, diploid and haploid chromosomes; 2) determine the generality of the initial observations by characterizing the properties of heterochromatic regions of the normal chromosome complement and 3) determine the molecular basis for the unusual physical properties of Dp (1;f) 1187 heterochromatic DNA. The novel nature of observations already made using this system suggest that continued analysis will reveal unanticipated aspects of DNA and chromosome structure of broad significance.