A Genome-Wide Survey of Sexually Dimorphic Expression of Drosophila miRNAs Identifies the Steroid Hormone-Induced miRNA let-7 as a Regulator of Sexual Identity

Fagegaltier, D., Konig, A., Gordon, A., Lai, E. C., Gingeras, T. R., Hannon, G. J., Shcherbata, H. R. (July 2014) A Genome-Wide Survey of Sexually Dimorphic Expression of Drosophila miRNAs Identifies the Steroid Hormone-Induced miRNA let-7 as a Regulator of Sexual Identity. Genetics, 198 (2). pp. 647-668. ISSN 0016-6731

URL: http://www.ncbi.nlm.nih.gov/pubmed/25081570
DOI: 10.1534/genetics.114.169268

Abstract

MiRNAs bear an increasing number of functions throughout development and in the aging adult. Here we address their role in establishing sexually dimorphic traits and sexual identity in male and female Drosophila. Our survey of miRNA populations in each sex identifies sets of miRNAs differentially expressed in male and female tissues across various stages of development. The pervasive sex-biased expression of miRNAs generally increases with the complexity and sexual dimorphism of tissues, gonads revealing the most striking biases. We find that the male-specific regulation of the X chromosome is relevant to miRNA expression on two levels. First, in the male gonad, testis-biased miRNAs tend to reside on the X chromosome. Second, in the soma, X-linked miRNAs do not systematically rely on dosage compensation. We set out to address the importance of a sex-biased expression of miRNAs in establishing sexually dimorphic traits. Our study of the conserved let-7-C miRNA cluster controlled by the sex-biased hormone ecdysone places let-7 as a primary modulator of the sex determination hierarchy. Flies with modified let-7 levels present doublesex-related phenotypes and express sex determination genes normally restricted to the opposite sex. In testes and ovaries, alterations of the ecdysone induced let-7 result in aberrant gonadal somatic cell behavior and non cell-autonomous defects in early germline differentiation. Gonadal defects as well as aberrant expression of sex determination genes persist in aging adults under hormonal control. Together, our findings place ecdysone and let-7 as modulators of a somatic systemic signal that helps establish and sustain sexual identity in males and females and differentiation in gonads. This work establishes the foundation for a role of miRNAs in sexual dimorphism and demonstrates that similar to vertebrate hormonal control of cellular sexual identity exists in Drosophila.

Item Type: Paper
Subjects: organism description > animal > insect > Drosophila
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > genomes
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > miRNA
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > miRNA
CSHL Authors:
Communities: CSHL labs > Gingeras lab
CSHL labs > Hannon lab
Depositing User: Matt Covey
Date: 31 July 2014
Date Deposited: 08 Aug 2014 19:12
Last Modified: 06 Apr 2015 16:45
PMCID: PMC4196619
Related URLs:
URI: http://repository.cshl.edu/id/eprint/30673

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