PT  - JOURNAL ARTICLE
AU  - Laura Moniot-Perron
AU  - Benoit Moindrot
AU  - Line Manceau
AU  - Joanne Edouard
AU  - Yan Jaszczyszyn
AU  - Pascale Gilardi-Hebenstreit
AU  - Céline Hernandez
AU  - Sébastien Bloyer
AU  - Daan Noordermeer
TI  - The <em>Drosophila</em> Fab-7 boundary element modulates <em>Abd-B</em> gene activity in the genital disc by guiding an inversion of collinear chromatin organization and alternative promoter use
AID  - 10.1101/2022.04.26.489596
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.04.26.489596
4099  - http://biorxiv.org/content/early/2022/04/26/2022.04.26.489596.short
4100  - http://biorxiv.org/content/early/2022/04/26/2022.04.26.489596.full
AB  - Hox genes encode transcription factors that specify segmental identities along the Antero-Posterior body axis. These genes are organized in clusters, where their order corresponds to their activity along the body axis, an evolutionary conserved feature known as collinearity. In Drosophila, the BX-C cluster contains the three most posterior Hox genes, where their collinear activation incorporates progressive replacement of histone modifications, reorganization of 3D chromatin architecture and sequential activation of boundary elements and cis-regulatory regions. To dissect functional hierarchies, we compared chromatin organization in larvae and in cell lines, with a focus on the Abd-B gene. Our work establishes the importance of the Fab-7 boundary element for insulation between 3D domains marked by different histone modifications. Interestingly, we detected a non-canonical inversion of collinear chromatin dynamics at the Abd-B gene, with the active histone domain decreasing in size. This chromatin organization differentially instructed alternative Abd-B promoter use, thereby expanding the possibilities to regulate transcriptional output.Competing Interest StatementThe authors have declared no competing interest.