副突变是一种表观遗传现象,通过同源基因间染色质状态信息的转移建立新的基因表达状态,这种表达状态能够通过减数分裂而传递到后代。玉米是研究副突变及其机制的模式植物,目前已经发现有5个基因位点能够发生副突变。对玉米b1副突变系统的广泛研究发现DNA重复序列、siRNA途径、DNA结合蛋白等在副突变状态的建立和维持过程中可能起着重要的作用。 Paratuberculosis is an epigenetic phenomenon that establishes a new gene expression state through the transfer of chromatin status information between homologous genes, which can be passed on to meiotic offspring through meiosis. Maize is a model plant for studying the secondary mutations and their mechanisms. Up to now, it has been found that five mutations can occur in five loci. Extensive studies on the b1 mutant system found that DNA repeats, siRNA pathways, DNA-binding proteins and others may play an important role in the establishment and maintenance of the paramyxovirus status.