标题:A 20-nucleotide element in the intestinal fatty acid binding protein gene modulates its cell lineage-specific, differentiation-dependent, and cephalocaudal patterns of expression in transgenic mice
期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1995
卷号:92
期号:19
页码:8685-8689
DOI:10.1073/pnas.92.19.8685
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:A sequence of epithelial cell proliferation, allocation to four principal lineages, migration-associated differentiation, and cell loss occurs along the crypt-villus axis of the mouse intestine. The sequence is completed in a few days and is recapitulated throughout the life-span of the animal. We have used an intestine-specific fatty acid binding protein gene, Fabpi, as a model for studying regulation of gene expression in this unique developmental system. Promoter mapping studies in transgenic mice identified a 20-bp cis-acting element (5'-AGGTGGAAGCCATCACACTT-3') that binds small intestinal nuclear proteins and participates in the control of Fabpi's cephalocaudal, differentiation-dependent, and cell lineage-specific patterns of expression. Immunocytochemical studies using confocal and electron microscopy indicate that it does so by acting as a suppressor of gene expression in the distal small intestine/colon, as a suppressor of gene activation in proliferating and nonproliferating cells located in the crypts of Lieberkuhn, and as a suppressor of expression in the growth factor and defensin-producing Paneth cell lineage. The 20-bp domain has no obvious sequence similarities to known transcription factor binding sites. The three functions modulated by this compact element represent the types of functions required to establish and maintain the intestine's remarkably complex spatial patterns of gene expression. The transgenes described in this report also appear to be useful in characterizing the crypt's stem cell hierarchy.