TRANSCRIPTION OF A SATELLITE DNA ON 2 Y-CHROMOSOME LOOPS OF DROSOPHILA-MELANOGASTER
TRANSCRIPTION OF A SATELLITE DNA ON 2 Y-CHROMOSOME LOOPS OF DROSOPHILA-MELANOGASTER
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DOI：
10.1007/bf01731701
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发表时间：
1990-08-01
期刊：
影响因子：
1.6
通讯作者：
LOHE, A
中科院分区：
文献类型：
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作者：
BONACCORSI, S;GATTI, M;LOHE, A
果蝇（Drosophilamelanogaster）初级精母细胞核呈现三个巨大的由Y染色体育性因子kl-5、kl-3和ks-1形成的灯刷状环。最近对Y染色体上卫星DNA序列沿着的详细作图表明，AA-GAC卫星重复序列是kl-5和ks-1环形成区的重要组成部分。为了确定这些简单的重复序列是否在环结构上转录，我们使用克隆的AAGAC重复序列作为探针对固定的环制备物进行了一系列DNA-RNA原位杂交实验。这些实验表明，探针杂交同源转录物特异性地与kl-5和ks-1环。这些成绩单检测在所有阶段的发展，这两个环，不出现迁移到细胞质和降解时，环解体在第一次减数分裂前期。此外，对睾丸的检查显示，AAGAC序列的转录仅限于初级精母细胞的环;黑腹精子发生不表现出核或细胞质标记。通过RNA印迹分析证实了这些实验，RNA印迹分析显示AAGAC序列的转录发生在野生型睾丸中，但不发生在X/O睾丸中。与RNA印迹杂交的模式表明，转录本的大小是高度异质性的，从大（在限制迁移率的迁移）到小于1 kb。我们讨论了AAGAC卫星转录本的可能功能，根据现有的信息，在Y染色体环的D。黑腹菌
Primary spermatocyte nuclei of Drosophila melanogaster exhibit three giant lampbrush-like loops formed by the kl-5, kl-3 and ks-1 Y chromosome fertility factors. Detailed mapping of satellite DNA sequences along the Y chromosome has recently shown that AA-GAC satellite repeats are a significant component of the kl-5 and ks-1 loop-forming regions. To determine whether these simple repeated sequences are transcribed on the loop structures we performed a series of DNA-RNA in situ hybridization experiments to fixed loop preparations using as a probe cloned AAGAC repeats. These experiments showed that the probe hybridizes with homologous transcripts specifically associated with the kl-5 and ks-1 loops. These transcripts are detected at all stages of development of these two loops, do not appear to migrate to the cytoplasm and are degraded when loops disintegrate during the first meiotic prophase. Moreover, an examination of the testes revealed that the transcription of the AAGAC sequences is restricted to the loops of primary spermatocytes; the other cell types of D. melanogaster spermatogenesis do not exhibit nuclear or cytoplasmic labeling. These experiments were confirmed by RNA blotting analysis which showed that transcription of the AAGAC sequences occurs in wild-type testes but not in X/O testes. The patterns of hybridization to the RNA blots indicated that the transcripts are highly heterogeneous in size, from large (migration at limiting mobility) to less than 1 kb. We discuss the possible function of the AAGAC satellite transcripts, in the light of the available information on the Y chromosome loops of D. melanogaster.