A shared ancient enhancer element differentially regulates the bric-a-brac tandem gene duplicates in the developing Drosophila leg
Por:
Bourbon H.-M.G., BenetahID, Mikhail H., GuillouID, Emmanuelle, Mojica-Vazquez, Luis Humberto, Baanannou, Aissette, Bernat-Fabre, Sandra, Loubiere, Vincent, Bantignies, Frederic, Cavalli, Giacomo, Boube, Muriel
Publicada:
1 mar 2022
Resumen:
Gene duplications and transcriptional enhancer emergence/modifications
are thought having greatly contributed to phenotypic innovations during
animal evolution. Nevertheless, little is known about how enhancers
evolve after gene duplication and how regulatory information is rewired
between duplicated genes. The Drosophila melanogaster bric-a-brac (bab)
complex, comprising the tandem paralogous genes bab1 and bab2, provides
a paradigm to address these issues. We previously characterized an
intergenic enhancer (named LAE) regulating bab2 expression in the
developing legs. We show here that bab2 regulators binding directly the
LAE also govern bab1 expression in tarsal cells. LAE excision by CRISPR/
Cas9-mediated genome editing reveals that this enhancer appears involved
but not strictly required for bab1 and bab2 co-expression in leg
tissues. Instead, the LAE enhancer is critical for paralog-specific bab2
expression along the proximo-distal leg axis. Chromatin features and
phenotypic rescue experiments indicate that LAE functions partly
redundantly with leg-specific regulatory information overlapping the
bab1 transcription unit. Phylogenomics analyses indicate that (i) the
bab complex originates from duplication of an ancestral singleton gene
early on within the Cyclorrhapha dipteran sublineage, and (ii) LAE
sequences have been evolutionarily-fixed early on within the Brachycera
suborder thus predating the gene duplication event. This work provides
new insights on enhancers, particularly about their emergence,
maintenance and functional diversification during evolution.
Filiaciones:
Bourbon H.-M.G.:
Center for Integrative Biology, Molecular Cellular and Developmental (MCD) Biology Unit, Federal University of Toulouse, Toulouse, France
BenetahID, Mikhail H.:
Center for Integrative Biology, Molecular Cellular and Developmental (MCD) Biology Unit, Federal University of Toulouse, Toulouse, France
GuillouID, Emmanuelle:
Center for Integrative Biology, Molecular Cellular and Developmental (MCD) Biology Unit, Federal University of Toulouse, Toulouse, France
Mojica-Vazquez, Luis Humberto:
Center for Integrative Biology, Molecular Cellular and Developmental (MCD) Biology Unit, Federal University of Toulouse, Toulouse, France
Baanannou, Aissette:
Center for Integrative Biology, Molecular Cellular and Developmental (MCD) Biology Unit, Federal University of Toulouse, Toulouse, France
Bernat-Fabre, Sandra:
Center for Integrative Biology, Molecular Cellular and Developmental (MCD) Biology Unit, Federal University of Toulouse, Toulouse, France
Loubiere, Vincent:
Institute of Human Genetics, University of Montpellier, CNRS Montpellier, France
Bantignies, Frederic:
Institute of Human Genetics, University of Montpellier, CNRS Montpellier, France
Cavalli, Giacomo:
Institute of Human Genetics, University of Montpellier, CNRS Montpellier, France
Boube, Muriel:
Center for Integrative Biology, Molecular Cellular and Developmental (MCD) Biology Unit, Federal University of Toulouse, Toulouse, France
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