Transposable element numbers in cosmopolitan inversions from a natural population of Drosophila melanogaster.
Transposable element numbers in cosmopolitan inversions from a natural population of Drosophila melanogaster.
复制标题
果蝇自然群体的世界性反转中的转座元件数量。
DOI：
10.1093/genetics/137.3.815
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发表时间：
1994
期刊：
影响因子：
3.3
通讯作者：
Charlesworth,B
中科院分区：
文献类型：
--
作者：
Sniegowski,PD;Charlesworth,B
对黑腹果蝇（Drosophila melanogaster）染色体上转座因子（te）分布的种群研究表明，由于转座而增加的拷贝数被某种形式的自然选择所平衡。理论表明，由于TE之间有害的异位减数分裂交换，选择倾向于TE拷贝数较低的基因组。这预示着te在重组减少的染色体区域的危害性更小，因此更丰富。为了验证这一点，我们从一个自然群体中调查了10个te家族在重组抑制染色体倒位中的丰度和位置。49条染色体的样本包括7种不同倒位的多个独立分离株和相应的一组标准染色体。对于所有10个TE家族，在低频反转内的拷贝数明显高于标准染色体相应区域内的拷贝数。te在In(3R)Mo和In(3R)K倒位中占据染色体位点的频率明显高于标准3R染色体的相应区域。这些结果与异位交换模型的预测一致。
Population studies of the distribution of transposable elements (TEs) on the chromosomes of Drosophila melanogaster have suggested that their copy number increase due to transposition is balanced by some form of natural selection. Theory suggests that, as a consequence of deleterious ectopic meiotic exchange between TEs, selection can favor genomes with lower TE copy numbers. This predicts that TEs should be less deleterious, and hence more abundant, in chromosomal regions in which recombination is reduced. To test this, we surveyed the abundance and locations of 10 families of TEs in recombination-suppressing chromosomal inversions from a natural population. The sample of 49 chromosomes included multiple independent isolates of seven different inversions and a corresponding set of standard chromosomes. For all 10 TE families pooled, copy numbers were significantly higher overall within low frequency inversions than within corresponding regions of standard chromosomes. TEs occupied chromosomal sites at significantly higher frequencies within the In(3R)Mo and In(3R)K inversions than within the corresponding regions of standard 3R chromosomes. These results are consistent with the predictions of the ectopic exchange model.