ON THE ROLE OF UNEQUAL EXCHANGE IN THE CONTAINMENT OF TRANSPOSABLE ELEMENT COPY NUMBER
ON THE ROLE OF UNEQUAL EXCHANGE IN THE CONTAINMENT OF TRANSPOSABLE ELEMENT COPY NUMBER
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DOI：
10.1017/s0016672300027695
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发表时间：
1988-12-01
影响因子：
1.5
通讯作者：
CHARLESWORTH, B
中科院分区：
文献类型：
--
作者：
LANGLEY, CH;MONTGOMERY, E;CHARLESWORTH, B
提出并分析了不对称配对和不平等交换在稳定转座因子拷贝数中作用的群体遗传学模型。Monte Carlo模拟表明，纳入分析的近似是强大的相关参数环。鉴于几个简单的假设有关的转座和切除，平等和不平等的交流，染色体结构，预测的相对数量的转座因子在不同地区的果蝇基因组进行比较，观察到的分布roo/B104元素在染色体区域的不同交换率，和X染色体和常染色体之间。没有迹象表明，在染色体的远端区域的元素的积累，这是预期在不平等的交换减少伴随着正常的交换在远端区域。然而，在染色体的近端区域中，相对于物理长度，存在过量元件的指示，其也具有受限的交换。这一观察结果与模型的预测定性一致。所观察到的元素在X染色体中段之间的分布与两种不平等交换模型之一的预测一致。
A population genetics model of the role of asymmetric pairing and unequal exchange in the stabilization of transposable element copy number in populations is proposed and analysed. Monte Carlo simulations indicate that the approximations incorporated into the analysis are robust in the relevant parameter rings. Given several simple assumptions concerning transposition and excision, equal and unequal exchange, and chromosome structure, predictions of the relative numbers of transposable elements in various regions of the Drosophila melanogaster genome are compared to the observed distribution of roo/B104 elements across chromosomal regions with differing rates of exchange, and between X chromosomes and autosomes. There is no indication of an accumulation of elements in the distal regions of chromosomes, which is expected in unequal exchange is reduced concomitantly with normal crossing over in the distal regions. There is, however, an indication of an excess of elements relative to physical length in the proximal regions of the chromosomes, which also have restricted crossing over. This observation is qualitatively consistent with the model''s predictions. The observed distribution of elements between the mid-sections of the X chromosomes and is consistent with the predictions of one of two models of unequal exchange.