A functional survey of the enhancer activity of conserved non-coding sequences from vertebrate Iroquois cluster gene desertsReportar como inadecuado




A functional survey of the enhancer activity of conserved non-coding sequences from vertebrate Iroquois cluster gene deserts - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Resumen

Recent studies of the genome architecture of vertebrates have uncovered two unforeseen aspects of its organization.First, large regions of the genome, called gene deserts, are devoid of protein-coding sequences and have no obviousbiological role. Second, comparative genomics has highlighted the existence of an array of highly conservednon-coding regions HCNRs in all vertebrates. Most surprisingly, these structural features are strongly associatedwith genes that have essential functions during development. Among these, the vertebrate Iroquois Irx genes standout on both fronts. Mammalian Irx genes are organized in two clusters IrxA and IrxB that span >1 Mb each with noother genes interspersed. Additionally, a large number of HCNRs exist within Irx clusters. We have systematicallyexamined the enhancer activity of HCNRs from the IrxB cluster using transgenic Xenopus and zebrafish embryos. Mostof these HCNRs are active in subdomains of endogenous Irx expression, and some are candidates to contain sharedenhancers of neighboring genes, which could explain the evolutionary conservation of Irx clusters. Furthermore,HCNRs present in tetrapod IrxB but not in fish may be responsible for novel Irx expression domains that appearedafter their divergence. Finally, we have performed a more detailed analysis on two IrxB ultraconserved non-codingregions UCRs duplicated in IrxA clusters in similar relative positions. These four regions share a core region highlyconserved among all of them and drive expression in similar domains. However, inter-species conserved sequencessurrounding the core, specific for each of these UCRs, are able to modulate their expression.



Autor: Calle Mustienes, Elisa de la; - Feijóo, Carmen Gloria; - Manzanares, Miguel; - Tena, Juan J.; - Rodríguez Seguel, Elisa; - Leti

Fuente: http://repositorio.uchile.cl/



DESCARGAR PDF




Documentos relacionados