Temporally regulated expression of Lin-28 in diverse tissues

被引:152
作者
Yang, DH [1 ]
Moss, EG [1 ]
机构
[1] Fox Chase Canc Ctr, Philadelphia, PA 19111 USA
关键词
mouse; embryo; lin-28; lin; 28; heterochronic gene; developmental timing; RNA-binding protein; intestinal epithelium; bronchial epithelium; muscle; retinoic acid;
D O I
10.1016/S1567-133X(03)00140-6
中图分类号
Q [生物科学];
学科分类号
07 ; 0710 ; 09 ;
摘要
The gene lin-28 was originally identified through a mutant of the nematode Caenorhabditis elegans displaying defects in developmental timing. It is expressed stage-specifically in tissues throughout the animal and is required for cell fates to be expressed at the appropriate stage of larval development. lin-28 encodes a cytoplasmic protein with a unique pairing of RNA-binding motifs. Diverse animals possess Lin-28 homologues and mouse Lin-28 is expressed in embryos, embryonic stem cells and embryonal carcinoma cells, but not in some differentiated cell types. To assess whether mammalian Lin-28 may function as a developmental timing regulator, we examined adult and embryonic tissues of the mouse for its expression. We observed Lin-28 protein in many diverse tissues of the embryo through the period of organogenesis and that it persists in some tissues in the adult. In addition to an overall down-regulation during embryogenesis, in at least two tissues Lin-28 expression shows temporal regulation, as opposed to cell type or tissue-specific regulation: in the developing bronchial epithelium, where it is present in the developing lung and absent in the adult, and in a subset of cells developing along the crypt-villus axis of the intestine. Interestingly, unlike epithelia, cardiac and skeletal muscle continuously express Lin-28, suggesting an ongoing need for its activity there. We also observed that Lin-28 expression is repressed during the retinoic acid-induced differentiation of mouse P19 cells into neuronal cells, suggesting that down-regulation of Lin-28 in some tissues may occur in response to hormonal signals that govern development. (C) 2003 Elsevier B.V. All rights reserved.
引用
收藏
页码:719 / 726
页数:8
相关论文
共 6 条