Skeletal muscles of the head and trunk originate in distinct lineages with divergent regulatory programmes converging on activation of myogenic determination factors. Branchiomeric head and neck muscles share a common origin with cardiac progenitor cells in cardiopharyngeal mesoderm (CPM). The retinoic acid (RA) signalling pathway is required during a defined early time window for normal deployment of cells from posterior CPM to the heart.
View Article and Find Full Text PDFThe translocator protein TSPO is an evolutionary conserved mitochondrial protein overexpressed in various contexts of neurodegeneration. Friedreich Ataxia (FA) is a neurodegenerative disease due to GAA expansions in the FXN gene leading to decreased expression of frataxin, a mitochondrial protein involved in the biosynthesis of iron-sulfur clusters. We previously reported that Tspo was overexpressed in a Drosophila model of this disease generated by CRISPR/Cas9 insertion of approximately 200 GAA in the intron of fh, the fly frataxin gene.
View Article and Find Full Text PDFFilamins are large proteins with actin-binding properties. Mutations in FLNC, one of the three filamin genes in humans, have recently been implicated in dominant cardiomyopathies, but the underlying mechanisms are not well understood. Here, we aimed to use Drosophila melanogaster as a new in vivo model to study these diseases.
View Article and Find Full Text PDFIn vertebrates, multipotent progenitors located in the pharyngeal mesoderm form cardiomyocytes and branchiomeric head muscles, but the dynamic gene expression programmes and mechanisms underlying cardiopharyngeal multipotency and heart versus head muscle fate choices remain elusive. Here, we used single-cell genomics in the simple chordate model Ciona to reconstruct developmental trajectories forming first and second heart lineages and pharyngeal muscle precursors and characterize the molecular underpinnings of cardiopharyngeal fate choices. We show that FGF-MAPK signalling maintains multipotency and promotes the pharyngeal muscle fate, whereas signal termination permits the deployment of a pan-cardiac programme, shared by the first and second heart lineages, to define heart identity.
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