The Chicken Skeletal Muscle α-Actin Promoter Is Tissue Specific in Transgenic Mice

Abstract

We have generated transgenic mouse lines that carry the promoter region of the chicken skeletal muscle α (α_sk) actin gene linked to the bacterial chloramphenicol acetyltransferase (CAT) gene. In adult mice, the pattern of transgene expression resembled that of the endogenous α_sk actin gene. In most of the transgenic lines, high levels of CAT activity were detected in striated muscle (skeletal and cardiac) but not in the other tissues tested. In striated muscle, transcription of the transgene was initiated at the normal transcriptional start site of the chicken α_sk actin gene. The region from nucleotides −191 to +27 of the chicken α_sk actin gene was sufficient to direct the expression of CAT in striated muscle of transgenic mice. These observations suggest that the mechanism of tissue-specific actin gene expression is well conserved in higher vertebrate species.