Lyon M F
MRC Radiobiology Unit, Didcot, Oxon, UK.
Trends Genet. 1993 Apr;9(4):123-8. doi: 10.1016/0168-9525(93)90206-w.
The epigenetic phenomena of genome imprinting and X-chromosome inactivation, found in mammals, both entail homologous genes or chromosomes behaving differently within the same cell. Although both have consequences for genic balance in the whole genome, in imprinting the control seems mainly at the single gene level, whereas in X-chromosome inactivation there is coordinated regulation of the whole chromosome, and single gene effects are relatively minor.
在哺乳动物中发现的基因组印记和X染色体失活这两种表观遗传现象，都意味着同源基因或染色体在同一细胞内表现不同。虽然两者都会对整个基因组的基因平衡产生影响，但在印记过程中，控制似乎主要在单个基因水平，而在X染色体失活中，整个染色体存在协调调控，单个基因的影响相对较小。
