Zhu H P, Ma D M, Gui J F
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Wuhan, 430072, China.
Chromosome Res. 2006;14(7):767-76. doi: 10.1007/s10577-006-1083-0. Epub 2006 Nov 22.
5S ribosomal DNA (rDNA) was isolated and sequenced from the gibel carp Carassius auratus gibelio with 162 chromosomes and crucian carp Carassius auratus with 100 chromosomes, and fluorescent probes for chromosome localization were prepared to ascertain the ploidy origin and evolutionary relationship between the two species. Using fluorescence in-situ hybridization (FISH), major 5S rDNA signals were localized to the short arms of three subtelocentric chromosomes in the gibel carp and to the short arms of two subtelocentrics in the crucian carp. In addition, some minor signals were detected on other chromosomes of both species. Simultaneously, six chromosomes were microdissected from the gibel carp metaphase spreads using glass needles, and the isolated chromosomes were amplified in vitro by degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR). Significantly, when the DOP-PCR-generated probes prepared from each single chromosome were hybridized, three same-sized chromosomes were painted in each gibel carp metaphase, whereas only two painted chromosomes were observed in each crucian carp metaphase spread. The data indicate that gibel carp is of triploid origin in comparison with diploid crucian carp.
从具有162条染色体的银鲫（Carassius auratus gibelio）和具有100条染色体的鲫鱼（Carassius auratus）中分离并测序了5S核糖体DNA（rDNA），并制备了用于染色体定位的荧光探针，以确定这两个物种的倍性起源和进化关系。使用荧光原位杂交（FISH）技术，主要的5S rDNA信号定位于银鲫三条亚端着丝粒染色体的短臂上，以及鲫鱼两条亚端着丝粒染色体的短臂上。此外，在两个物种的其他染色体上也检测到了一些次要信号。同时，使用玻璃针从银鲫中期染色体铺片中显微切割出六条染色体，并通过简并寡核苷酸引物聚合酶链反应（DOP-PCR）对分离出的染色体进行体外扩增。值得注意的是，当用从每条单染色体制备的DOP-PCR产生的探针进行杂交时，在每个银鲫中期染色体铺片中可观察到三条大小相同的染色体被标记，而在每个鲫鱼中期染色体铺片中仅观察到两条被标记的染色体。数据表明，与二倍体鲫鱼相比，银鲫起源于三倍体。
