Kogan G L, Tulin A V, Aravin A A, Abramov Yu A, Kalmykova A I, Maisonhaute C, Gvozdev V A
Department of Animal Molecular Genetics, Institute of Molecular Genetics, 123182 Moscow, Russia.
Mol Genet Genomics. 2003 May;269(2):234-42. doi: 10.1007/s00438-003-0827-1. Epub 2003 Mar 14.
A full-length copy of the retrotransposon GATE was identified as an insertion in the tandemly repeated, heterochromatic, Stellate genes, which are expressed in the testis of Drosophila melanogaster. Sequencing of this heterochromatic GATE copy revealed that it is closely related to the BEL retrotransposon, a representative of the recently defined BEL-like group of LTR retrotransposons. This copy contains identical LTRs, indicating that the insertion is a recent event. By contrast, the euchromatic part of the D. melanogaster genome contains only profoundly damaged GATE copies or fragments of the transposon. The preferential localization of GATE sequences in heterochromatin was confirmed for the other species in the melanogaster subgroup. The level of GATE expression is dramatically increased in ovaries, but not in testes, of spn-E(1) homozygous flies. We speculate that spn-E is involved in the silencing of GATE via an RNA interference mechanism.
反转录转座子GATE的一个全长拷贝被鉴定为插入到串联重复的异染色质星状基因中，这些基因在黑腹果蝇的睾丸中表达。对这个异染色质GATE拷贝的测序显示，它与BEL反转录转座子密切相关，BEL反转录转座子是最近定义的LTR反转录转座子BEL样组的代表。这个拷贝包含相同的长末端重复序列（LTRs），表明该插入是一个近期事件。相比之下，黑腹果蝇基因组的常染色质部分仅包含严重受损的GATE拷贝或转座子片段。在黑腹果蝇亚组的其他物种中也证实了GATE序列在异染色质中的优先定位。在spn-E(1)纯合果蝇的卵巢中，GATE的表达水平显著增加，但在睾丸中没有增加。我们推测spn-E通过RNA干扰机制参与了GATE的沉默。
