TY - JOUR AU - Maclean, Norman AB - 10.1002/(SICI)1098-2795(199708)47:4<404::AID-MRD6>3.3.CO;2-F The transient expression of reporter gene constructs in embryos provides a powerful tool to characterise cis‐acting transcriptional elements of the genes involved in development. In the present study, we have analysed the expression pattern of several muscle‐specific and ubiquitous regulatory sequences in microinjected zebrafish embryos. By using a fast and reproducible coinjection strategy, the mosaic expression of lacZ reporter gene was monitored in wholemount embryos injected with sequences containing putative enhancer elements and a carp myosin heavy chain promoter/lacZ reporter construct. We have found that a 0.9‐kb myosin heavy chain (MyHC) proximal promoter containing several putative myogenic regulatory factors (MRF) binding sites is sufficient to restrict lacZ expression to the skeletal muscle fibres of prim‐6 stage zebrafish embryos. Expression of a rat‐derived foetal myosin light chain enhancer (MyLC) and different fragments of a carp β‐actin regulatory region together with the MyHC promoter were compared by accumulating the type, number and spatial distribution of β‐galactosidase‐expressing cells on an expression map. β‐galactosidase activity increased similarly whether the MyLC enhancer was ligated to the promoter/reporter construct directly or when coinjected as a separate fragment whilst skeletal muscle specificity was retained. The coinjection of two different forms of the β‐actin regulatory elements also showed a marked effect on the MyHC promoter activity. The coinjection of putative enhancers with minimal promoter constructs and subsequent analysis of the transient expression pattern in the developing embryos provides a rapid and simple technique to identify cis acting activator elements of genes expressed in the vertebrate embryo. Mol. Reprod. Dev. 47:404–412, 1997. © 1997 Wiley‐Liss, Inc. TI - Activator effect of coinjected enhancers on the muscle‐specific expression of promoters in zebrafish embryos JF - Molecular Reproduction & Development DO - 10.1002/(SICI)1098-2795(199708)47:4<404::AID-MRD6>3.0.CO;2-O DA - 1998-12-07 UR - https://www.deepdyve.com/lp/wiley/activator-effect-of-coinjected-enhancers-on-the-muscle-specific-40q3vzUfOE SP - 404 EP - 412 VL - 47 IS - 4 DP - DeepDyve ER -