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Dbx2 regulation in limbs suggests inter TAD sharing of enhancers
Author(s) -
Beccari Leonardo,
Jaquier Gabriel,
LopezDelisle Lucille,
RodriguezCarballo Eddie,
Mascrez Bénédicte,
Gitto Sandra,
Woltering Joost,
Duboule Denis
Publication year - 2021
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.303
Subject(s) - enhancer , biology , hox gene , transcription factor , gene , chromatin , locus (genetics) , genetics , limb development , phenotype , microbiology and biotechnology , homeobox , enhancer rnas
Background During tetrapod limb development, the HOXA13 and HOXD13 transcription factors are critical for the emergence and organization of the autopod, the most distal aspect where digits will develop. Since previous work had suggested that the Dbx2 gene is a target of these factors, we set up to analyze in detail this potential regulatory interaction. Results We show that HOX13 proteins bind to mammalian‐specific sequences at the vicinity of the Dbx2 locus that have enhancer activity in developing digits. However, the functional inactivation of the DBX2 protein did not elicit any particular phenotype related to Hox genes inactivation in digits, suggesting either redundant or compensatory mechanisms. We report that the neighboring Nell2 and Ano6 genes are also expressed in distal limb buds and are in part controlled by the same Dbx2 enhancers despite being localized into two different topologically associating domains (TADs) flanking the Dbx2 locus. Conclusions We conclude that Hoxa13 and Hoxd genes cooperatively activate Dbx2 expression in developing digits through binding to mammalian specific regulatory sequences in the Dbx2 neighborhood. Furthermore, these enhancers can overcome TAD boundaries in either direction to co‐regulate a set of genes located in distinct chromatin domains.