AUTHOR=Esteves de Lima Joana , Bou Akar Reem , Mansour Myriam , Rocancourt Didier , Buckingham Margaret , Relaix Frédéric 

TITLE=M-Cadherin Is a PAX3 Target During Myotome Patterning

JOURNAL=Frontiers in Cell and Developmental Biology

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2021.652652

DOI=10.3389/fcell.2021.652652

ISSN=2296-634X

ABSTRACT=<p>PAX3 belongs to the paired-homeobox family of transcription factors and plays a key role as an upstream regulator of muscle progenitor cells during embryonic development. <italic>Pax3</italic>-mutant embryos display impaired somite development, yet the consequences for myotome formation have not been characterized. The early myotome is formed by PAX3-expressing myogenic cells that delaminate from the dermomyotomal lips and migrate between the dermomyotome and sclerotome where they terminally differentiate. Here we show that in <italic>Pax3</italic>-mutant embryos, myotome formation is impaired, displays a defective basal lamina and the regionalization of the structural protein Desmin is lost. In addition, this phenotype is more severe in embryos combining <italic>Pax3</italic>-null and <italic>Pax3</italic> dominant-negative alleles. We identify the adhesion molecule M-Cadherin as a PAX3 target gene, the expression of which is modulated in the myotome according to <italic>Pax3</italic> gain- and loss-of-function alleles analyzed. Taken together, we identify M-Cadherin as a PAX3-target linked to the formation of the myotome.</p>