Genomic imprinting is the epigenetic phenomenon by which certain genes are expressed in a parent-of-origin-specific manner, and was first discovered in mammalian embryos. Recent studies have shown that it also occurs in developing plant seeds, and is now becoming a hot topic of biology of plant seed development. According to the previous studies on imprinted genes, imprinting mechanism and their roles in plant seed development, the current progress of genomic imprinting in plant seed development was summarized and possible strategies were proposed to deal with the problems, which could provide helpful information for further research.
目的研究胰岛素样生长因子2(insulin like growth factor2,Igf2)基因的印迹状态及其表达在早期自然流产中的作用。方法选择2010年2月至2011年2月在中国医科大学附属盛京医院节育门诊就诊孕妇60例,采用PCR结合限制性片段长度多态性分析(restriction fragment length polymorphism,RFLP)技术,分析25例正常早孕、35例早孕自然流产绒毛组织中Igf2基因印迹丢失(loss of imprinting,LOI)情况;采用荧光定量PCR方法检测两种绒毛组织Igf2基因mRNA的表达。结果正常绒毛组织中Igf2基因型为杂合子的样本有11例,其中4例被检测出印迹丢失;自然流产绒毛组织中Igf2基因型为杂合子的样本有16例,其中6例被检测出印迹丢失,二者相比差异无统计学意义(P>0.05)。自然流产绒毛组织中Igf2基因mRNA的表达量为(2.29±0.60)×103copy/μgRNA,明显低于正常绒毛组织中Igf2基因的表达量(3.15±0.88)×103copy/μgRNA,两者比较差异有统计学意义(P<0.001)。结论 Igf2基因的印迹丢失与自然流产无关,Igf2基因mRNA的表达降低与自然流产有关,在早期自然流产发生中可能存在其他机制调节Igf2基因的表达。
