Ho Thien, Rusholme Pilcher Rachel L, Edwards Mary-Lou, Cooper Ian, Dalmay Tamas, Wang Hui
NERC/Centre for Ecology and Hydrology (CEH) Oxford, Mansfield Road, Oxford OX1 3SR, UK.
Biochem Biophys Res Commun. 2008 Apr 4;368(2):433-7. doi: 10.1016/j.bbrc.2008.01.110. Epub 2008 Feb 1.
Dicot Dicer-like (DCL) enzymes operate preferably on GC rich regions when producing small interfering (si)RNA and micro (mi)RNA. This GC bias, however, is not generic in monocot miRNA productions. From wild Dactylis glomerata naturally infected by Cocksfoot streak potyvirus (CSV), CSV-siRNAs had a greater GC% than the virus genome, indicating that GC rich regions were also preferred by the grass DCLs. This supports the notion that GC preference is an ancient feature for plant DCLs, and suggests that monocot miRNA genes might have evolved to a high GC% resulting in GC bias being not detectable during mature miRNA production.
双子叶植物中类似Dicer（DCL）的酶在产生小干扰（si）RNA和微小（mi）RNA时，优先作用于富含GC的区域。然而，这种GC偏好性在单子叶植物miRNA的产生中并非普遍存在。在自然感染鸭茅条斑马铃薯Y病毒（CSV）的野生鸭茅中，CSV-siRNAs的GC含量高于病毒基因组，这表明禾本科植物的DCL也偏好富含GC的区域。这支持了GC偏好是植物DCL古老特征的观点，并表明单子叶植物miRNA基因可能已经进化到具有较高的GC含量，从而在成熟miRNA产生过程中无法检测到GC偏好。
