Common origin of B chromosome variants in the grasshopper Eyprepocnemis plorans
Common origin of B chromosome variants in the grasshopper Eyprepocnemis plorans
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DOI：
10.1038/sj.hdy.6885960
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发表时间：
1999-10-01
期刊：
影响因子：
3.8
通讯作者：
Camacho, JPM
中科院分区：
文献类型：
--
作者：
Cabrero, J;López-León, MD;Camacho, JPM
从西班牙的4个地点和摩洛哥的3个地点采集的7个不同的Eypropocnemis plorans种群中的9个B染色体变异体已被证明主要由两个DNA序列组成，即180 bp的串联重复序列和核糖体DNA。然而，B型在两种序列的相对量上不同。分布最广的一个（B-1）具有大约相同量的rDNA和180 bp重复，但是通过在较小区域中替换B-1而达到多态性的另外三个变体（B-2、B-5和B-24）具有明显更大量的180 bp重复。在摩洛哥，最普遍的B变异也是B-1，一种出现在单个个体中的罕见变异也是用相同的两个DNA序列构建的。所有这些数据都表明这些B染色体有一个共同的起源，B-1可能是最初的一个。讨论了不同B类型的起源以及180 bp DNA重复序列的相对数量与B驱动的可能关系。
Nine B chromosome variants, from seven different populations of Eyprepocnemis plorans collected at four localities in Spain and three in Morocco, have been shown to be mainly composed of two DNA sequences, i.e. a 180-bp tandem repeat and ribosomal DNA. B types, however, differ in the relative amounts of the two sequences. The most widespread one (B-1) bears about the same amount of rDNA and 180 bp repeat, but three other variants that have reached a polymorphism by replacing B-1 in smaller areas (B-2, B-5 and B-24) carry a conspicuously larger amount of the 180 bp repeat. In Morocco, the most widespread B variant is also B-1, and a rare variant that appeared in a single individual is also built with the same two DNA sequences. All these data point to a common origin for these B chromosomes, with B-1 probably being the original one. The origin of the different B types and the possible relationship of the relative amount of 180 bp DNA repeat with B drive are discussed.