Teruel M, Cabrero J, Perfectti F, Acosta M J, Sánchez A, Camacho J P M
Departamento de Genética, Universidad de Granada, Granada, Spain.
Cytogenet Genome Res. 2009;125(4):286-91. doi: 10.1159/000235935. Epub 2009 Oct 27.
The relative location of 2 repetitive DNAs, i.e. ribosomal (rDNA) and a tandemly repeated satellite DNA (satDNA), with respect to the centromere, suggested that B chromosomes in the grasshopper Eyprepocnemis plorans derived intraspecifically from the X chromosome. To test this hypothesis, we microdissected X and B chromosomes and amplified the obtained DNA by 2 different procedures, the conventional DOP-PCR method and the single-cell whole-genome amplification GenomePlex method. We then generated DNA probes to perform chromosome painting. Our results have confirmed that X and B chromosomes share many DNA sequences between them and with most of the autosomes, especially at locations where the satDNA and rDNA reside, in consistency with previous information. This supports the hypothesis of an intraspecific origin of B chromosomes in E. plorans. Nevertheless, the present results did not help to clarify whether Bs were derived from the X chromosome or else from 1 or more autosomes.
两种重复DNA，即核糖体DNA（rDNA）和串联重复卫星DNA（satDNA），相对于着丝粒的相对位置表明，蚱蜢Eyprepocnemis plorans中的B染色体是在种内从X染色体衍生而来的。为了验证这一假设，我们对X染色体和B染色体进行了显微切割，并通过两种不同的方法对获得的DNA进行扩增，即传统的DOP-PCR方法和单细胞全基因组扩增GenomePlex方法。然后我们制备了DNA探针进行染色体涂染。我们的结果证实，X染色体和B染色体之间以及与大多数常染色体共享许多DNA序列，特别是在satDNA和rDNA所在的位置，这与先前的信息一致。这支持了E. plorans中B染色体种内起源的假设。然而，目前的结果无助于阐明B染色体是源自X染色体，还是源自一条或多条常染色体。
