Pathak Rupak, Koturbash Igor, Hauer-Jensen Martin
Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences;
Department of Environmental Health, Fay W. Boozman School of Public Health, University of Arkansas for Medical Sciences.
J Vis Exp. 2017 Jan 11(119):55162. doi: 10.3791/55162.
Ionizing radiation (IR) induces numerous stable and unstable chromosomal aberrations. Unstable aberrations, where chromosome morphology is substantially compromised, can easily be identified by conventional chromosome staining techniques. However, detection of stable aberrations, which involve exchange or translocation of genetic materials without considerable modification in the chromosome morphology, requires sophisticated chromosome painting techniques that rely on in situ hybridization of fluorescently labeled DNA probes, a chromosome painting technique popularly known as fluorescence in situ hybridization (FISH). FISH probes can be specific for whole chromosome/s or precise sub-region on chromosome/s. The method not only allows visualization of stable aberrations, but it can also allow detection of the chromosome/s or specific DNA sequence/s involved in a particular aberration formation. A variety of chromosome painting techniques are available in cytogenetics; here two highly sensitive methods, multiple fluorescence in situ hybridization (mFISH) and spectral karyotyping (SKY), are discussed to identify inter-chromosomal stable aberrations that form in the bone marrow cells of mice after exposure to total body irradiation. Although both techniques rely on fluorescent labeled DNA probes, the method of detection and the process of image acquisition of the fluorescent signals are different. These two techniques have been used in various research areas, such as radiation biology, cancer cytogenetics, retrospective radiation biodosimetry, clinical cytogenetics, evolutionary cytogenetics, and comparative cytogenetics.
电离辐射（IR）可诱导产生大量稳定和不稳定的染色体畸变。不稳定畸变会使染色体形态严重受损，通过传统的染色体染色技术即可轻松识别。然而，稳定畸变涉及遗传物质的交换或易位，而染色体形态并无显著改变，检测此类畸变需要复杂的染色体涂染技术，该技术依赖于荧光标记DNA探针的原位杂交，这是一种通常被称为荧光原位杂交（FISH）的染色体涂染技术。FISH探针可以针对整条染色体或染色体上的精确亚区域具有特异性。该方法不仅能够可视化稳定畸变，还能检测特定畸变形成过程中涉及的染色体或特定DNA序列。细胞遗传学中有多种染色体涂染技术；在此讨论两种高度灵敏的方法，即多重荧光原位杂交（mFISH）和光谱核型分析（SKY），以识别全身照射后小鼠骨髓细胞中形成的染色体间稳定畸变。尽管这两种技术都依赖于荧光标记的DNA探针，但荧光信号的检测方法和图像采集过程有所不同。这两种技术已应用于多个研究领域，如辐射生物学、癌症细胞遗传学、回顾性辐射生物剂量测定、临床细胞遗传学、进化细胞遗传学和比较细胞遗传学。
