Takahashi Chigusa
Faculty of Education and Regional Sciences, Tottori University, Tottori 680-8551, Japan.
J Plant Res. 2003 Aug;116(4):331-6. doi: 10.1007/s10265-003-0104-8. Epub 2003 Jun 19.
The chromosomal locations of the 18S-5.8S-26S rDNA and 5S rDNA sequences were examined in four cytotypes of Ranunculus silerifolius (the Matsuyama, Mugi, Otaru, and Karatsu types) using fluorescence in situ hybridization (FISH). Using the 18S-5.8S-26S rDNA probe, one pair of probe hybridization sites was detected by FISH in the interstitial region corresponding to the secondary constriction on the short arm of a satellite chromosome (chromosome pair 6) in all four karyotypes. FISH using 5S rDNA identified one pair of sites. The 5S rDNA locus was on different chromosomes in the four karyotypes: in the interstitial region of the short arm of the largest metacentric chromosome (chromosome pair 1) in the Matsuyama type, in the interstitial region of the short arm of the subtelocentric chromosome (pair 2) in the Mugi and Otaru types, and in the interstitial region of the short arm of the metacentric chromosome (pair 2) in the Karatsu type. This physical mapping of the 5S rDNA provides valuable information about karyotype evolution in R. silerifolius. Possible mechanisms of chromosome evolution are discussed.
利用荧光原位杂交（FISH）技术，在毛茛叶毛茛（松山型、麦型、小樽型和唐津型）的四种细胞型中检测了18S - 5.8S - 26S rDNA和5S rDNA序列的染色体定位。使用18S - 5.8S - 26S rDNA探针，通过FISH在所有四种核型中与随体染色体（第6号染色体对）短臂上的次缢痕相对应的中间区域检测到一对探针杂交位点。使用5S rDNA的FISH鉴定出一对位点。5S rDNA基因座在四种核型中的不同染色体上：松山型位于最大中着丝粒染色体（第1号染色体对）短臂的中间区域，麦型和小樽型位于亚端着丝粒染色体（第2号染色体对）短臂的中间区域，唐津型位于中着丝粒染色体（第2号染色体对）短臂的中间区域。5S rDNA的这种物理图谱为毛茛叶毛茛的核型进化提供了有价值的信息。文中还讨论了染色体进化的可能机制。
