Accumulation of Spock and Worf, two novel non-LTR retrotransposons, on the neo-Y chromosome of Drosophila miranda
Accumulation of Spock and Worf, two novel non-LTR retrotransposons, on the neo-Y chromosome of Drosophila miranda
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DOI：
10.1093/molbev/msg035
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发表时间：
2003-02-01
影响因子：
10.7
通讯作者：
Bachtrog, D
中科院分区：
文献类型：
--
作者：
Bachtrog, D
转座元件构成真核基因组的主要部分。在这里，我描述了从米兰达果蝇的新 Y 染色体克隆的两个新型非 LTR 逆转录转座子。 Worf 大小为 4.1 kb，与按蚊中表征的 TI-2 非 LTR 转座子具有同源性。 Spock 大小为 4.9 kb，与黑腹果蝇的 Doc 元素相似。两种元素的 Southern 印迹分析产生了更强的男性 DNA 信号。多线染色体原位杂交表明，这两个元件都积累在米兰达 D. miranda 的 Neo-Y 染色体上。进行 PCR 分析以调查 12 个 D. miranda 品系的各个染色体位点上 spock 和 worf 以及先前鉴定的转座子 TRIM 和 TRAM 的频率。与果蝇各个位点的元件频率通常保持较低的观察相反，所研究的四个转座子固定在新 Y 染色体上的基因组位置。这些结果支持转座子在非重组区域积累并可能是性染色体异态性的原因之一的假设。
Transposable elements constitute a major fraction of eukaryotic genomes. Here, I characterize two novel non-LTR retrotransposons, cloned from the neo-Y chromosome of Drosophila miranda. Worf is 4.1 kb in size and shows homology to the TI-2 non-LTR transposon characterized in Anopheles. Spock is 4.9 kb in size and shows similarity to the Doc element of D. melanogaster. Southern blot analysis of both elements yielded stronger signals for male DNA. In situ hybridization to polytene chromosomes revealed that both elements are accumulating on the neo-Y chromosome of D. miranda. PCR analysis was conducted to investigate the frequency of spock and worf and of the previously identified transposons, TRIM and TRAM, at individual chromosomal sites among 12 strains of D. miranda. Contrary to the observation that element frequencies are usually kept low at individual sites in Drosophila, the four transposons investigated are fixed at their genomic locations on the neo-Y chromosome. These results support the hypothesis that transposons accumulate in nonrecombining regions and may be one cause of the heteromorphism of sex chromosomes.