Spatial regulation of microRNA gene expression in the Drosophila embryo

Item Type:	Article
Title:	Spatial regulation of microRNA gene expression in the Drosophila embryo
Creators Name:	Biemar, F. and Zinzen, R.P. and Ronshaugen, M. and Sementchenko, V. and Manak, J.R. and Levine, M.S.
Abstract:	MicroRNAs (miRNAs) regulate posttranscriptional gene activity by binding to specific sequences in the 3' UTRs of target mRNAs. A number of metazoan miRNAs have been shown to exhibit tissue-specific patterns of expression. Here, we investigate the possibility that localized expression is mediated by tissue-specific enhancers, comparable to those seen for protein-coding genes. Two miRNA loci in Drosophila melanogaster are investigated, the mir-309-6 polycistron (8-miR) and the mir-1 gene. The 8-miR locus contains a cluster of eight distinct miRNAs that are transcribed in a common precursor RNA. The 8-miR primary transcript displays a dynamic pattern of expression in early embryos, including repression at the anterior and posterior poles. An 800-bp 5' enhancer was identified that recapitulates this complex pattern when attached to a RNA polymerase II core promoter fused to a lacZ-reporter gene. The miR-1 locus is specifically expressed in the mesoderm of gastrulating embryos. Bioinformatics methods were used to identify a mesoderm-specific enhancer located approximately 5 kb 5' of the miR-1 transcription unit. Evidence is presented that the 8-miR enhancer is regulated by the localized Huckebein repressor, whereas miR-1 is activated by Dorsal and Twist. These results provide evidence that restricted activities of the 8-miR and miR-1 miRNAs are mediated by classical tissue-specific enhancers.
Keywords:	Development, Enhancer, Transcription, Animals, Drosophila melanogaster
Source:	Proceedings of the National Academy of Sciences of the United States of America
ISSN:	0027-8424
Publisher:	National Academy of Sciences
Volume:	102
Number:	44
Page Range:	15907-15911
Date:	1 November 2005
Official Publication:	https://doi.org/10.1073/pnas.0507817102
PubMed:	View item in PubMed

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