多色-FISH技术的进展及其在分子生物医学上的应用

The Progress in M-FISH and Its Applications in Molecular Biological Medicine

传统显带分析技术以每条染色体独特的显带带型为依据,提供染色体形态结构的基本信息,用于染色体核型的初步分析。然而有些染色体重排由于涉及的片断太小或具有相似的带型,用该方法难以探测或准确描绘。多元荧光原位杂交(M-FISH),光谱核型分析(SKY),FISH-显带分析技术是染色体特异的多色荧光原位杂交技术(mFISH)。它们能够探测出传统显带分析不能发现的染色体异常,提供更准确的核型。M-FISH和SKY均以组合标记的染色体涂染探针共杂交为基础,二者的不同在于观察仪器和分析方法上。它们可对中期染色体涂片进行快速准确分析,描绘复杂核型,确认标记染色体,主要用于恶性疾病的细胞遗传学诊断分析。FISH-显带分析技术以FISH技术为基础,能同时检测多条比染色体臂短的染色体亚区域。符合该定义的FISH-显带分析技术各有特点,其共同特点是都能产生DNA特异的染色体条带。这些条带有更多色彩,能提供更多信息。FISH-显带分析技术已经成功地被用于进化生物学、放射生物学以及核结构的研究,同时也被用于产前、产后以及肿瘤细胞遗传学诊断,是很有潜力的工具。

Classical banding methods, such as G-banding, provide basic information about the identifies and structures of chromosomes on the basis of their unique banding patterns; remain the techniques of choice for the initial screening for karyotypic abnormalities. However, sometimes chromosomal rearrangements involves segments too small or too similarly banded to be detected or described adequately by these techniques. Multiplex fluorescence in situ hybridization （M-FISH）, spectral karytyping （SKY）, and related FISH-banding techniques are chromosome-specific multicolor FISH techniques （mFISH） that augment cytogenetic evaluations by providing additional information and improved characterization of aberrant chromosomes that contain DNA sequences not identifiable using conventional banding methods. M-FISH and SKY are based on cohybridization of combinatorially labeled chromosome painting probes with unique fluorochrome signatures onto human metaphase chromosome preparations. The difference between them is the image acquisition and analysis. They can give rapid analysis of metaphase spread even in complex cases with multiple chromosomal rearrangements, and identification of marker chromosomes. FISH-banding techniques were recently defined as ＂any kind of FISH technique, which provide the possibility to characterize simultaneously several chromosomal subregions smaller than a chromosome arm. FISH- banding methods fitting that definition may have quite different characteristics, but share the ability to produce a DNA-specific chromosomal banding＂. While the standard chromosome banding techniques like GTG lead to a protein-related black and white banding pattern, FISH-banding techniques are DNA-specific, more colorful and, thus, more informative. FISH-banding methods have successfully been applied in research in evolution- and radiation-biology, as well as in all studies on the nuclear architecture. Moreover, their suitability for diagnostic purposes has been proven in prenatal, postnatal and tumor cytogenetics, indicating that they are important tool with potential to partly replace the conventional banding techniques in the future.