Genomic imprinting results in the expression of genes in a parent-of-origin-dependent manner. The mechanism and developmental consequences of genomic imprinting are most well characterized in mammals, plants, and certain insect species (e.g., sciarid flies and coccid insects). However, researchers have observed imprinting phenomena in species in which imprinting of endogenous genes is not known to exist or to be developmentally essential. In this review, I survey the known mechanisms of imprinting, focusing primarily on examples from mammals, where imprinting is relatively well characterized. Where appropriate, I draw attention to imprinting mechanisms in other organisms to compare and contrast how diverse organisms employ different strategies to perform the same process. I discuss how the various mechanisms come into play in the context of the imprint life cycle. Finally, I speculate why imprinting may be more widely prevalent than previously thought.

中文翻译：

---

基因组印迹的机械视图。

基因组印迹导致基因以起源于母体的方式表达。基因组印迹的机制和发育后果在哺乳动物，植物和某些昆虫物种（例如eg虫和lies虫）中得到了最充分的表征。但是，研究人员已经在物种中发现了烙印现象，其中不存在内源基因的烙印或在胚胎发育中至关重要。在这篇综述中，我调查了已知的印迹机制，主要集中在哺乳动物的印迹特征相对较好的例子上。在适当的地方，我提请注意其他生物中的印迹机制，以比较和对比不同生物如何采用不同策略来执行相同过程。我讨论了各种机制在烙印生命周期的背景下如何发挥作用。最后，我推测为什么烙印可能比以前认为的更为普遍。