title: Oesophageal and sternohyal muscle fibres are novel Pax3-dependent migratory somite derivatives essential for ingestion.
abstract: Striated muscles that enable mouth opening and swallowing during feeding are essential for efficient energy acquisition, and are likely to have played a fundamental role in the success of early jawed vertebrates. The developmental origins and genetic requirements of these muscles are uncertain. Here, we determine by indelible lineage tracing in mouse that fibres of sternohyoid muscle (SHM), which is essential for mouth opening during feeding, and oesophageal striated muscle (OSM), which is crucial for voluntary swallowing, arise from Pax3-expressing somite cells. In vivo Kaede lineage tracing in zebrafish reveals the migratory route of cells from the anteriormost somites to OSM and SHM destinations. Expression of pax3b, a zebrafish duplicate of Pax3, is restricted to the hypaxial region of anterior somites that generate migratory muscle precursors (MMPs), suggesting that Pax3b plays a role in generating OSM and SHM. Indeed, loss of pax3b function led to defective MMP migration and OSM formation, disorganised SHM differentiation, and inefficient ingestion and swallowing of microspheres. Together, our data demonstrate Pax3-expressing somite cells as a source of OSM and SHM fibres, and highlight a conserved role of Pax3 genes in the genesis of these feeding muscles of vertebrates.
authors.affiliation: Randall Division of Cell and Molecular Biophysics, New Hunt's House, Guy's Campus, King's College London, London SE1 1UL, UK.
authors.forename: James E N
authors.initials: JE
authors.lastname: Minchin
authors.forename: Victoria C
authors.initials: VC
authors.lastname: Williams
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Hinits
authors.forename: Siewhui
authors.initials: S
authors.lastname: Low
authors.forename: Panna
authors.initials: P
authors.lastname: Tandon
authors.forename: Chen-Ming
authors.initials: CM
authors.lastname: Fan
authors.forename: John F
authors.initials: JF
authors.lastname: Rawls
authors.forename: Simon M
authors.initials: SM
authors.lastname: Hughes
mesh_terms: D000818:Animals; D002465:Cell Movement; D003679:Deglutition; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism; D004947:Esophagus / Q000166:cytology / Q000196:embryology*; D005333:Fetus / Q000166:cytology / Q000378:metabolism; D007568:Jaw / Q000166:cytology / Q000196:embryology*; D051379:Mice; D024510:Muscle Development; D054792:Muscle, Striated / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D017570:MyoD Protein / Q000378:metabolism; D051787:Myogenic Regulatory Factor 5 / Q000378:metabolism; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics / Q000378:metabolism*; D019170:Somites / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D017570:MyoD Protein; D051787:Myogenic Regulatory Factor 5; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors; D029961:Zebrafish Proteins; C489412:pax3a protein, zebrafish; C068686:Pax3 protein, mouse
keywords: Hypaxial muscle; In vivo lineage tracing; Mouse; Pax3; Zebrafish