人类X染色体失活与基因的剂量补偿效应

Human X chromosome inactivation and gene dosage compensation effect

人类通过女性的一条X染色体随机失活的方式对X连锁的基因进行表达的调控,以实现基因的剂量补偿效应,目前对X失活机制的研究表明,X染色体上的失活中心通过表达的非编码RNA对所在染色体进行顺式调控,但结构异常的X染色体的失活并不是随机的,有关X染色体失活机理的研究有待深入。

Human females have two copies of each X-linked genes,however,males have only one copy,but the products of the X-linked genes are almost expressed at the same level,this can be explained by the Lyon hypothesis. The main point of Lyon hypothesis is only one X chromosome is transcriptionally inactive and this process occurs randomly,the inactive X maybe paternal origin or maternal origin. Recent researches show that X chromosome inactivation can be nonrandom,and the molecular mechanism of X chromosome inactivation is still waiting for uncovering.