Zhou Y, Cambareri E B, Kinsey J A
Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City 66160, USA.
Mol Genet Genomics. 2001 Jun;265(4):748-54. doi: 10.1007/s004380100472.
Tad is a LINE-like retrotransposon of the filamentous fungus Neurospora crassa. We have analyzed both expression and transposition of this element using strains with a single copy of Tad located in the 5' noncoding sequences of the am (glutamate dehydrogenase) gene. Tad in this position has been shown to carry a de novo cytosine methylation signal which causes reversible methylation of both Tad and am upstream sequences. Here we find that methylation of the Tad sequences inhibits both Tad expression and transposition. This inhibition can be relieved by the use of 5-azacytidine, a drug which reduces cytosine methylation, or by placing the Tad/am sequences in a dim-2 genetic background.
Tad是丝状真菌粗糙脉孢菌中的一种类LINE反转录转座子。我们使用在am（谷氨酸脱氢酶）基因5'非编码序列中含有单个Tad拷贝的菌株，分析了该元件的表达和转座情况。已证明处于此位置的Tad携带一个从头胞嘧啶甲基化信号，该信号会导致Tad和am上游序列的可逆甲基化。在此我们发现，Tad序列的甲基化会抑制Tad的表达和转座。使用5-氮杂胞苷（一种可降低胞嘧啶甲基化的药物），或将Tad/am序列置于dim-2遗传背景中，均可解除这种抑制作用。
