Distal cis-acting elements restrict expression of the CyIIIb actin gene in the aboral ectoderm of the sea urchin embryo
| Autor: | Constantin N. Flytzanis, Elizabeth A. Bogosian, Christina C. Niemeyer, Naidi Xu, Maria F. Gonzalez-Rimbau |
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| Rok vydání: | 1996 |
| Předmět: |
Chloramphenicol O-Acetyltransferase
Embryology animal structures Embryo Nonmammalian Time Factors Mutant Ectoderm Regulatory Sequences Nucleic Acid medicine Animals Tissue Distribution RNA Messenger Promoter Regions Genetic Gene In Situ Hybridization Reporter gene biology Base Sequence Wild type Gene Expression Regulation Developmental Embryo biology.organism_classification Blastula Strongylocentrotus purpuratus Molecular biology Actins medicine.anatomical_structure Sea Urchins embryonic structures Mutagenesis Site-Directed Developmental Biology |
| Zdroj: | Mechanisms of development. 60(2) |
| ISSN: | 0925-4773 |
| Popis: | The distal region of the S. purpuratus actin CyIIIb gene, between −400 and −1400 nucleotides, contains at least three distinct cis-acting elements (C1R, C1L and E1) which are necessary for correct expression of fusion reporter genes in transgenic sea urchin embryos. The contribution of these elements in the temporal and spatial regulation of the gene was analyzed by single and double site-directed mutagenesis in fusion constructs which carry the bacterial chloramphenicol acetyl transferase (CAT) gene as a reporter. Following microinjection of the transgenes in sea urchin embryos, the activity of the mutants was compared to the wild type in time and space by measuring CAT activity at the blastula and pluteus embryonic stages and by in situ hybridization to the CAT mRNA at pluteus stage. Our results indicate that E1 involved in the temporal regulation of CyIIIb and that all three elements are necessary and sufficient to confer aboral (dorsal) ectoderm specificity to the proximal promoter. This is achieved by suppressing the promoter's activity in all other tissues by the cooperative interaction of the cis-acting elements. The C1R element, binding site of the nuclear receptors SpCOUP-TF and SpSHR2, is by itself sufficient to restrict expression in the ectoderm, whereas the aboral ectoderm restricted expression requires in addition the presence of both C1L adn E1. It is therefore evident, that the actin CyIIIb gene is exclusively expressed in the aboral ectoderm by a combinatorial repression in all other cell lineages of the developing embryo. |
| Databáze: | OpenAIRE |
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