Dingerkus G, Howell W M
Science. 1976 Nov 19;194(4267):842-4. doi: 10.1126/science.982045.
A model chromosome number of 120 was obtained for the ancient fish. Polyodon spathula (Pisces: Chondrostei). The karyotype consists of 48 macrochromosomes and 72 microchromosomes. The microchromosomes are like those found in certain other primitive fishes as well as in reptiles and birds. The possiblity that Polyodon is a species of tetraploid origin is strongly suggested by the fact that the 120 chromosomes are easily arranged into 30 groups of four homologs each. Evolutionary comparisons are made with other primitive fish groups.
已确定古老鱼类匙吻鲟（硬骨鱼纲：软骨硬鳞鱼亚纲）的染色体模式数为120。其核型由48条大染色体和72条小染色体组成。这些小染色体与某些其他原始鱼类以及爬行动物和鸟类中的小染色体相似。匙吻鲟是四倍体起源物种的可能性因120条染色体很容易被分成30组、每组有四条同源染色体这一事实而得到有力证明。文中还与其他原始鱼类群体进行了进化比较。
