Biology of the X chromosome.
Biology of the X chromosome.
复制标题
X 染色体的生物学。
DOI：
10.1097/00008480-200108000-00010
复制
发表时间：
2001
影响因子：
3.6
通讯作者：
Goldman,MA
中科院分区：
文献类型：
--
作者：
Gartler,SM;Goldman,MA
X染色体的生物学特性是独特的，因为女性有两个X，而男性只有一个X，而常染色体在两性中都是重复的。只有一个常染色体的存在，可能是减数分裂分离错误的结果，这总是胚胎致死事件。由于剂量补偿，X染色体的单体是可行的，这是一种存在于所有具有X: Y形式性别决定的生物体中的系统，它使大多数X连锁基因在雌性和雄性中表达相等。在哺乳动物中，剂量补偿系统包括沉默一条X染色体上的大多数基因；它被称为X染色体失活。在这篇综述中，我们首先关注我们对X失活机制的分子基础的理解的最新进展。然后我们考虑X失活的一个不寻常的特征，雌性的镶嵌性质和随后暴露于体细胞选择。
The biology of the X chromosome is unique, as there are two Xs in females and only a single X in males, whereas the autosomes are present in duplicate in both sexes. The presence of only a single autosome, which can occur as a result of an error in meiotic segregation, is invariably an embryonic lethal event. Monosomy for the X chromosome is viable because of dosage compensation, a system found in all organisms with an X: Y form of sex determination, which brings about equality of expression of most X-linked genes in females and males. In mammals, the dosage compensation system involves silencing of most of the genes on one X chromosome; it is called X chromosome inactivation. In this review, we focus first on recent advances in our understanding of the molecular basis of the X inactivation mechanism. Then we consider an unusual feature of X inactivation, the mosaic nature of the female and subsequent exposure to somatic cell selection.