HUMAN GENOME ORGANIZATION
HUMAN GENOME ORGANIZATION
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DOI：
10.1016/0959-437x(95)80045-x
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发表时间：
1995-06-01
影响因子：
4
通讯作者：
GARDINER, K
中科院分区：
文献类型：
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作者：
GARDINER, K
最近的进展已经在解决三个有趣的方面人类基因组的组织：染色体内的蛋白质编码序列的组织，中期染色体带型的结构基础，和非蛋白质编码DNA的功能。在细胞遗传学水平上，R带异质性已被研究荧光原位杂交使用复杂的基因组DNA片段作为探针。根据GC含量和CpG岛密度进行DNA分级，产生与G和R带相关的模式，并直接显示基因密度的区域差异。已经提出了中期带的结构基础，其基于G带与R带中DNA环和基质附着位点的不同大小和包装。该模型为结构/功能和组织调查提供了有趣的机会。在分子水平上，人类基因组计划已经导致了许多大的染色体区域的广泛的基因组克隆覆盖，允许详细记录CpG岛，碱基组成和重复序列内容，以及推动全面的基因搜索。序列和功能特征正在被检查在DNA酶水平，并提示新的建议的作用，'垃圾' DNA。由于这些发展，现在出现了直接评估单个中期条带的分子特征的机会。
Recent advances have been made in addressing three intriguing aspects of human genome organization: the organization of protein-coding sequences within chromosomes, the structural basis of the metaphase chromosomal banding pattern, and the function of non protein coding DNA. At the cytogenetic level, R band heterogeneity has been examined by fluorescence in situ hybridization using complex fractions of genomic DNA as probes. DNA fractionated according to GC content and CpG island density both generated patterns related to G and R bands and directly demonstrated regional variations in gene densities. A structural basis for metaphase bands has been proposed that is based on the differential size and packing oi DNA loops and matrix attachment sites in G versus R bands. The model presents interesting opportunities for structure/function and organization investigations. At the molecular level, the human genome initiative has resulted in extensive genomic clone coverage for many large chromosomal regions, permitting detailed documentation of CpG islands, base composition and repeat sequence content, as well as fueling comprehensive gene searches. Sequence and functional characteristics are being examined at the kilobase level and are prompting new suggestions of roles for 'junk' DNA. Because of these developments, opportunities are now emerging for direct assessment of the molecular characteristics of individual metaphase bands.