Temperature shift coordinately changes the activity and the methylation state of transposon Tam3 in Antirrhinum majus
Temperature shift coordinately changes the activity and the methylation state of transposon Tam3 in Antirrhinum majus
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DOI：
10.1104/pp.102.017533
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发表时间：
2003-07-01
期刊：
影响因子：
7.4
通讯作者：
Kishima, Y
中科院分区：
文献类型：
--
作者：
Hashida, S;Kitamura, K;Kishima, Y
与大多数其他剪切粘贴型转座子不同，金鱼草中Tam3的转座频率受到温度的严格控制：Tam3在25 ℃时很少转座，但在15 ℃时转座频率要高得多。在这里，我们研究了低温依赖性转座（LTDT）的Tam3的机制。我们的研究结果强烈表明，LTDT是不太可能是由于转录调控或转录后调控的Tam3 Tclase基因。我们发现，温度变化诱导了基因组中Tam3序列特有的甲基化状态的显着变化：较高的温度导致超甲基化，而较低的温度导致甲基化降低。甲基化状态是可逆的，在一个单一的代内响应于温度变化。虽然我们的数据表明LTDT和Tam3甲基化之间存在密切联系，但它们也表明除DNA甲基化以外的次要因素参与Tam3转座的抑制。
The transposition frequency of Tam3 in Antirrhinum majus, unlike that of most other cut-and-paste-type transposons, is tightly controlled by temperature: Tam3 transposes rarely at 25degreesC, but much more frequently at 15degreesC. Here, we studied the mechanism of the low-temperature-dependent transposition (LTDT) of Tam3. Our results strongly suggest that LTDT is not likely to be due to either transcriptional regulation or posttranscriptional regulation of the Tam3 TPase gene. We found that temperature shift induced a remarkable change of the methylation state unique to Tam3 sequences in the genome: Higher temperature resulted in hypermethylation, whereas lower temperature resulted in reduced methylation. The methylation state was reversible within a single generation in response to a temperature shift. Although our data demonstrate a close link between LTDT and the methylation of Tam3, they also suggest that secondary factor(s) other than DNA methylation is involved in repression of Tam3 transposition.