Gornung E
'Charles Darwin' Department of Biology and Biotechnologies, University of Rome 'La Sapienza', Rome, Italy.
Cytogenet Genome Res. 2013;141(2-3):90-102. doi: 10.1159/000354832. Epub 2013 Sep 28.
Molecular cytogenetic data on the number and position of 45S ribosomal RNA genes (rDNA; located in nucleolus organizing regions, NORs) detected by FISH in 330 species of 77 families and 22 orders of bony fishes (Teleostei) and, additionally, 11 species of basal ray-finned fishes are compiled and analyzed. The portion of species with single rDNA sites in the sample amounts to 72%. The percentage of species with multiple NORs decreases with increasing numbers of rDNA loci per genome, i.e. scarcely 3% of species carry 4 or more rDNA-bearing chromosome pairs. 43% of all rDNA sites analyzed occur terminally on the short arms of chromosomes or constitute them. In general, terminal rDNA sites account for 87% of all examined cases. Interspecific variation in the location of single rDNA sites among related taxa, polymorphisms of multiple NORs in some groups of teleosts and analytical outcomes on the subject are reviewed.
汇编并分析了通过荧光原位杂交（FISH）在77科22目硬骨鱼（真骨鱼类）的330个物种以及另外11种基干辐鳍鱼中检测到的45S核糖体RNA基因（rDNA；位于核仁组织区，NORs）的数量和位置的分子细胞遗传学数据。样本中具有单个rDNA位点的物种比例为72%。具有多个NORs的物种百分比随着每个基因组中rDNA位点数量的增加而降低，即几乎只有3%的物种携带4个或更多含rDNA的染色体对。分析的所有rDNA位点中有43%位于染色体短臂末端或构成短臂。总体而言，末端rDNA位点占所有检查案例的87%。回顾了相关分类群中单rDNA位点位置的种间变异、一些硬骨鱼群体中多个NORs的多态性以及该主题的分析结果。
