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Sex-lethal regulates back-splicing and generation of the sex-differentially expressed circular RNAs.

ABSTRACT: Conversely to canonical splicing, back-splicing connects the upstream 3' splice site (SS) with a downstream 5'SS and generates exonic circular RNAs (circRNAs) that are widely identified and have regulatory functions in eukaryotic gene expression. However, sex-specific back-splicing in Drosophila has not been investigated and its regulation remains unclear. Here, we performed multiple RNA analyses of a variety sex-specific Drosophila samples and identified over ten thousand circular RNAs, in which hundreds are sex-differentially and -specifically back-spliced. Intriguingly, we found that expression of SXL, an RNA-binding protein encoded by Sex-lethal (Sxl), the master Drosophila sex-determination gene that is only spliced into functional proteins in females, promoted back-splicing of many female-differential circRNAs in the male S2 cells, whereas expression of a SXL mutant (SXLRRM) did not promote those events. Using a monoclonal antibody, we further obtained the transcriptome-wide RNA-binding sites of SXL through PAR-CLIP. After splicing assay of mini-genes with mutations in the SXL-binding sites, we revealed that SXL-binding on flanking exons and introns of pre-mRNAs facilitates back-splicing, whereas SXL-binding on the circRNA exons inhibits back-splicing. This study provides strong evidence that SXL has a regulatory role in back-splicing to generate sex-specific and -differential circRNAs, as well as in the initiation of sex-determination cascade through canonical forward-splicing.

SUBMITTER: Fan YJ

PROVIDER: S-EPMC10250224 | biostudies-literature | 2023 Jun

REPOSITORIES: biostudies-literature

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Sex-lethal regulates back-splicing and generation of the sex-differentially expressed circular RNAs.

Fan Yu-Jie YJ Ding Zhan Z Zhang Yu Y Su Ruibao R Yue Jia-Le JL Liang An-Min AM Huang Qi-Wei QW Meng Yan-Ran YR Li Muwang M Xue Yuanchao Y Xu Yong-Zhen YZ

Nucleic acids research 20230601 10

Conversely to canonical splicing, back-splicing connects the upstream 3' splice site (SS) with a downstream 5'SS and generates exonic circular RNAs (circRNAs) that are widely identified and have regulatory functions in eukaryotic gene expression. However, sex-specific back-splicing in Drosophila has not been investigated and its regulation remains unclear. Here, we performed multiple RNA analyses of a variety sex-specific Drosophila samples and identified over ten thousand circular RNAs, in whic ...[more]

PMID: 37070178

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Sex-lethal regulates back-splicing and generation of the sex-differentially expressed circular RNAs.

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Sex-lethal regulates back-splicing and generation of the sex-differentially expressed circular RNAs.

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