Lampert Kathrin P, Lamatsch Dunja K, Fischer Petra, Schartl Manfred
Department of Physiological Chemistry I, University of Wuerzburg, Biozentrum, Am Hubland, 97074 Wuerzburg, Germany.
J Hered. 2008 Mar-Apr;99(2):223-6. doi: 10.1093/jhered/esm102. Epub 2008 Jan 21.
Polyploidization is thought to be an important driving force in evolution as it increases the genetic material on which mutation and selection can act. In the Amazon molly, Poecilia formosa, triploid genotypes can be found in the field and frequently arise from diploid breeding stocks, a tetraploid individual, however, was so far never documented. Here, we report the first tetraploid Amazon molly. Flow cytometry clearly showed the tetraploid DNA content, whereas microsatellite analysis not only confirmed the tetraploidy but also pointed to allotetraploidy. Most likely the fourth genome was received through paternal leakage, namely, by fertilization of a triploid egg with a haploid sperm. The existence of tetraploid individuals offers new explanations for the enormous clonal diversity observed in wild populations of P. formosa.
多倍体化被认为是进化中的一个重要驱动力，因为它增加了可供突变和选择作用的遗传物质。在亚马孙帆鳉（Poecilia formosa）中，三倍体基因型在野外可以发现，并且经常从二倍体繁殖种群中产生，然而，迄今为止从未记录到四倍体个体。在此，我们报告首例四倍体亚马孙帆鳉。流式细胞术清楚地显示了四倍体的DNA含量，而微卫星分析不仅证实了四倍体状态，还表明是异源四倍体。最有可能的是，第四个基因组是通过父本渗漏获得的，即由一个单倍体精子使一个三倍体卵子受精。四倍体个体的存在为在亚马孙帆鳉野生种群中观察到的巨大克隆多样性提供了新的解释。
