Lee S H, Do G S, Seo B B
Department of Biology, Kyungpook National University, Taegu, Korea.
Chromosome Res. 1999;7(2):89-93. doi: 10.1023/a:1009222411001.
Chromosomal localizations and distribution patterns of the 5S rRNA genes by means of fluorescence in-situ hybridization in diploid Allium species could help to classify species into chromosome types and aid in determining relationships among genomes. All eleven diploid species were classified into five types, A to E. Species of type A showed a pair of 5S rRNA signals on the short arm of chromosome 5 and two pairs of signals on both arms of chromosome 7. Species of types B and C showed one pair and two pairs of signals on the short arm of chromosome 7, respectively. Type D species showed two pairs of signals on the satellite region of the short arm and a pair of signals on the long arm of chromosome 7. Type E species showed three distinct 5S rRNA gene loci signals on the short arm of chromosome 7. Information on chromosomal localization of 5S rRNA gene loci and distribution patterns within chromosomes in diploid Allium species could help to infer the pathway of origin of the three kinds of alloploid species. Data indicate that A. wakegi is an allopolyploid with genomes of types B and C, and A. deltoide-fistulosum is an allotetraploid derived from a natural hybridization between different species within chromosome type A. Results indicate that A. senescens is an allopolyploid with type B chromosomes and an unidentified chromosomal type.
通过荧光原位杂交技术研究二倍体葱属物种中5S rRNA基因的染色体定位和分布模式，有助于将物种分类为染色体类型，并有助于确定基因组之间的关系。所有11个二倍体物种被分为A至E五种类型。A类型的物种在5号染色体短臂上显示一对5S rRNA信号，在7号染色体双臂上显示两对信号。B类型和C类型的物种分别在7号染色体短臂上显示一对和两对信号。D类型的物种在7号染色体短臂的随体区域显示两对信号，在长臂上显示一对信号。E类型的物种在7号染色体短臂上显示三个不同的5S rRNA基因座信号。二倍体葱属物种中5S rRNA基因座的染色体定位信息和染色体内的分布模式有助于推断三种异源多倍体物种的起源途径。数据表明，韭菜是具有B和C类型基因组的异源多倍体，三角葱是源自A染色体类型内不同物种自然杂交的异源四倍体。结果表明，衰老葱是具有B染色体类型和未鉴定染色体类型的异源多倍体。
