Makowski E R, Ruzin S E
University of California, Department of Plant Biology, Berkeley 94720.
Biotechniques. 1994 Feb;16(2):256-8, 260-3.
Knob heterochromatin served as the model for the development of fluorescent chromosome in situ hybridization on maize meiotic chromosomes. The meiotic chromosomes were hybridized with a digoxigenin-labeled RNA probe of the knob repeat sequence that is a component of the morphologically determined knob heterochromatin. The fluorescein-labeled knob probe and propidium iodide counter-stained chromosomes were imaged using confocal laser scanning microscopy, which allowed for the individual analysis of each fluorescent probe emission intensity, the ability to utilize image processing techniques and the generation of high-resolution images. A composite, in register, merged image of the knob probe signal and meiotic chromosomes demonstrated exact co-localization of the knob probe and the morphologically identified knobs. The establishment of the fluorescent in situ hybridization technique in maize allows for the expanded study of the biological role of knob heterochromatin and the possibility of locating other repeat sequences on maize chromosomes.
着丝粒异染色质是玉米减数分裂染色体荧光原位杂交技术发展的模型。减数分裂染色体与地高辛标记的着丝粒重复序列RNA探针杂交，该序列是形态学上确定的着丝粒异染色质的组成部分。使用共聚焦激光扫描显微镜对着丝粒荧光探针和碘化丙啶复染的染色体进行成像，这使得能够对每个荧光探针的发射强度进行单独分析，利用图像处理技术并生成高分辨率图像。着丝粒探针信号与减数分裂染色体的合成、对齐、合并图像显示着丝粒探针与形态学鉴定的着丝粒精确共定位。玉米荧光原位杂交技术的建立使得着丝粒异染色质生物学作用的研究得以扩展，并且有可能在玉米染色体上定位其他重复序列。
