The genomic rate of transposable element movement in Drosophila melanogaster.
The genomic rate of transposable element movement in Drosophila melanogaster.
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DOI：
10.1093/oxfordjournals.molbev.a040188
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发表时间：
1995
影响因子：
10.7
通讯作者：
S. Nuzhdin;T. Mackay
中科院分区：
文献类型：
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作者：
S. Nuzhdin;T. Mackay
真核生物DNA的很大一部分是由转座因子（te）组成的（Berg and Howe 1989），当它们转座到新的位点时可能导致突变（Mackay et al. 1992）。TE诱导突变对总基因组突变率的相对贡献取决于所有TE家族平均每代每个基因组的转位和切除率。在对果蝇近交系的独立重复中直接观察到转位和切除的实验中，估计每代每个单倍体基因组的总转位率为0.5 （Eggleston等人1988年）0.3 （Harada等人1990年）和0.6 （Nuzhdin和Mackay 1994年）；总切除率分别为0.04 （Eggleston et al. 1988）、0.003 （Harada et al. 1990）和0.006 （Nuzhdin and Mackay 1994）。这些估计具有非常高的标准误差，因为很少有调换和切除被检测到（Eggleston等人，1988），或者因为只检查了元素家族的一小部分样本（Harada等人，1990；Nuzhdin和Mackay 1994）。我们之前对D. melunogaster TE的总转座率和切除率的估计是基于3个I复制系的5个反转录转座子TE家族（Dot, copia, roo， 297和w2dg3）的细胞学插入位点，这些系来自一个最初高度近交系（Harwith），已经积累了大约170代的突变（Nuzhdin和Mackay 1994）。为了根据更大比例的TE家族获得更精确的估计，我们在10个Harwich突变积累系的样本中确定了12个额外的TE（1731、mdgl、412、gypsy、hobo、FB4、2156、2158、2161、2217、2244和I）的插入位点，这些突变积累系自第一次研究以来经历了大约10代的突变积累。10个品系的平均突变积累世代数为175代。TE插入部位由in确定
A large fraction of eukaryotic DNA is composed of transposable elements (TEs) (Berg and Howe 1989) that can cause mutations when they transpose to novel sites (Mackay et al. 1992). The relative contribution of TE-induced mutations to the total genomic mutation rate depends on the rate of transposition and excision per genome per generation averaged over all TE families. Experiments in which transpositions and excisions have been observed directly in independent replicates of inbred lines of Drosophila melunogaster yield estimates of the total transposition rate per haploid genome per generation of 0.5 (Eggleston et al. 1988) 0.3 (Harada et al. 1990), and 0.6 (Nuzhdin and Mackay 1994); and for the total excision rate of 0.04 (Eggleston et al. 1988), 0.003 (Harada et al. 1990) and 0.006 (Nuzhdin and Mackay 1994). These estimates have very high standard errors because very few transpositions and excisions were detected (Eggleston et al. 1988) or because only a small sample of element families was examined (Harada et al. 1990; Nuzhdin and Mackay 1994). Our previous estimate of the total rate of transposition and excision of D. melunogaster TEs was based on cytological insertion sites of 5 retrotransposon TE families (Dot, copia, roo, 297, and w2dg3) in 3 I replicate lines derived from an initially highly inbred strain (Harwith) that had accumulated mutations for approximately 170 generations (Nuzhdin and Mackay 1994). To obtain a more precise estimate based on a larger proportion of TE families, we have determined insertion sites of 12 additional TEs (1731, mdgl, 412, gypsy, hobo, FB4, 2156, 2158, 2161, 2217, 2244, and I) in a sample of 10 Harwich mutation accumulation lines that had undergone approximately 10 further generations of mutation accumulation since the first study. The average number of generations of mutation accumulation for these 10 lines was 175. TE insertion sites were determined by in