Actinotrichia are the first exoskeletal elements formed during zebrafish fin development. These rigid fibrils serve as skeletal support for the fin fold and as substrates for mesenchymal cell migration. In the adult intact fins, actinotrichia are restricted to the distal domain of the fin. Following fin amputation, actinotrichia also reform during regeneration. The actinodin gene family codes for structural proteins of actinotrichia. We have previously identified cis- acting regulatory elements in a 2kb genomic region upstream of the first exon of actinodin1 , termed 2P, required for tissue-specific expression in the fin fold ectoderm and mesenchyme during embryonic development. Indeed, 2P contains an ectodermal enhancer in a 150bp region named epi . Deletion of epi from 2P results in loss of ectodermal-specific activity. In the present study, we sought to further characterize the activity of these regulatory sequences throughout fin development and during adult fin regeneration. Using a reporter transgenic approach, we show that a site within the epi region, termed epi3 , contains an early mesenchymal-specific repressor. We also show that the larval fin fold ectodermal enhancer within epi3 remains functional in the basal epithelial layer during fin regeneration. We show that the first non-coding exon and first intron of actinodin1 contains a transcriptional enhancer and an alternative promoter that are necessary for the persistence of reporter expression reminiscent of actinodin1 expression during adulthood. Altogether, we have identified cis -acting regulatory elements that are required for tissue-specific expression as well as full recapitulation of actinodin1 expression during adulthood. Furthermore, the characterization of these elements provides us with useful molecular tools for the enhancement of transgene expression in adulthood.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.