First Author | Yang DH | Year | 2003 |
Journal | Gene Expr Patterns | Volume | 3 |
Issue | 6 | Pages | 719-26 |
PubMed ID | 14643679 | Mgi Jnum | J:86961 |
Mgi Id | MGI:2682506 | Doi | 10.1016/s1567-133x(03)00140-6 |
Citation | Yang DH, et al. (2003) Temporally regulated expression of Lin-28 in diverse tissues of the developing mouse. Gene Expr Patterns 3(6):719-26 |
abstractText | 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. |