cis-acting DNA regulatory elements, including the retinoic acid response element, are required for tissue specific laminin B1 promoter/lacZ expression in transgenic mice

The LAMB1 gene encodes the laminin pi subunit of laminin, an extracellular matrix protein. Using several transgenic mouse lines containing various len gths of the LAMB1 promoter driving lac Z reporter gene expression, regions of LAMB I promoter that contain cis-acting DNA regulatory element(s) have b een identified. The 3.9LAMB1 beta gal transgene is expressed in various tis sues during development. LAMB1 transgene expression is observed in a select ive set of nephrons of the neonatal and adult kidneys. The cis-acting DNA r egulatory elements responsible for LAMB1 transgene expression in ovaries an d in juvenile kidneys are present between -1.4 and -0.7 kt, relative to the transcription start site, while those of adult kidneys are located between -2.5 and -1.4 kb. The LAMBI transgene is also expressed in the epididymis of 1 week old transgenic mice. Mutation of the retinoic acid response eleme nt (RARE) in the context of the 3.9LAMB1 beta gal transgene results in loss of LAMB1 transgene expression in all tissues. Thus, sequences between -2.5 and -0.7 kb plus the RARE are required for appropriate expression of the L AMBI transgene in mice. (C) 2001 Elsevier Science Ireland Ltd. All rights r eserved.