Ocalewicz Konrad, Jankun Malgorzata, Luczynski Miroslaw
Department of Evolutionary Genetics, WM University in Olsztyn, Oczapowskiego 5, 10-718 Olsztyn-Kortowo, Poland.
Folia Biol (Krakow). 2003;51(1-2):41-6.
The development of high resolution methods of chromosome banding helped the finding of homologous chromosomes, detecting chromosomal abnormalities, and assigning the gene loci to particular chromosomes in mammals. Unfortunately, small and numerous fish chromosomes do not show GC rich and GC poor compartments, this preventing the establishment of G banding pattern. The combination of techniques enabling the identification of constitutive heterochromatin (C-banding), heterochromatin resistant to restriction endonucleas, NOR bearing chromosomes (AgNO3 banding), or AT rich regions on chromosomes (DAPI banding) in sequential staining provides a better characteristic of fish chromosomes. In this work sequentially DAPI, DdeI, AgNO3 stained chromosomes of rainbow trout resulted in the characteristic banding pattern of some homologous chromosomes. Procedure of FISH with telomere probe and DAPI as a counterstaining fluorochrome visualized simultaneous hybridization signals and DAPI banding. Possibility of detection both FISH and DAPI signals can help in procedures of gene mapping on chromosomes.
高分辨率染色体显带方法的发展有助于在哺乳动物中寻找同源染色体、检测染色体异常以及将基因位点定位到特定染色体上。不幸的是，鱼类的染色体小且数量众多，没有显示出富含GC和缺乏GC的区域，这使得无法建立G带模式。通过连续染色，能够鉴定组成型异染色质（C带）、抗限制性内切酶的异染色质、携带核仁组织区的染色体（硝酸银显带）或染色体上富含AT的区域（DAPI显带）的技术组合，可以更好地描绘鱼类染色体的特征。在这项工作中，对虹鳟鱼的染色体依次进行DAPI、DdeI、硝酸银染色，得到了一些同源染色体的特征性显带模式。用端粒探针进行荧光原位杂交（FISH）并以DAPI作为复染荧光染料的程序，可以同时观察到杂交信号和DAPI显带。检测FISH和DAPI信号的可能性有助于染色体上的基因定位过程。
