|ZFIN ID: ZDB-PUB-140513-286|
Evolutionarily conserved morphogenetic movements at the vertebrate head-trunk interface coordinate the transport and assembly of hypopharyngeal structures
Lours-Calet, C., Alvares, L.E., El-Hanfy, A.S., Gandesha, S., Walters, E.H., Sobreira, D.R., Wotton, K.R., Jorge, E.C., Lawson, J.A., Kelsey Lewis, A., Tada, M., Sharpe, C., Kardon, G., Dietrich, S.
|Source:||Developmental Biology 390: 231-46 (Journal)|
|Registered Authors:||Lawson, Jennifer, Tada, Masazumi|
|Keywords:||Chicken, Circumpharyngeal route, Evolution of vertebrate developmental mechanisms, Floor of pharynx, Head–trunk interface, Hypobranchial/hypoglossal muscle, Migratory muscle precursors, Morphogenetic movements, Mouse, Occipital ectoderm, Occipital lateral mesoderm, Occipital neural crest, Occipital somites, Pharyngeal arches, Xenopus, Zebrafish|
|PubMed:||24662046 Full text @ Dev. Biol.|
Lours-Calet, C., Alvares, L.E., El-Hanfy, A.S., Gandesha, S., Walters, E.H., Sobreira, D.R., Wotton, K.R., Jorge, E.C., Lawson, J.A., Kelsey Lewis, A., Tada, M., Sharpe, C., Kardon, G., Dietrich, S. (2014) Evolutionarily conserved morphogenetic movements at the vertebrate head-trunk interface coordinate the transport and assembly of hypopharyngeal structures. Developmental Biology. 390:231-46.
ABSTRACTThe vertebrate head-trunk interface (occipital region) has been heavily remodelled during evolution, and its development is still poorly understood. In extant jawed vertebrates, this region provides muscle precursors for the throat and tongue (hypopharyngeal/hypobranchial/hypoglossal muscle precursors, HMP) that take a stereotype path rostrally along the pharynx and are thought to reach their target sites via active migration. Yet, this projection pattern emerged in jawless vertebrates before the evolution of migratory muscle precursors. This suggests that a so far elusive, more basic transport mechanism must have existed and may still be traceable today. Here we show for the first time that all occipital tissues participate in well-conserved cell movements. These cell movements are spearheaded by the occipital lateral mesoderm and ectoderm that split into two streams. The rostrally directed stream projects along the floor of the pharynx and reaches as far rostrally as the floor of the mandibular arch and outflow tract of the heart. Notably, this stream leads and engulfs the later emerging HMP, neural crest cells and hypoglossal nerve. When we (i) attempted to redirect hypobranchial/hypoglossal muscle precursors towards various attractants, (ii) placed non-migratory muscle precursors into the occipital environment or (iii) molecularly or (iv) genetically rendered muscle precursors non-migratory, they still followed the trajectory set by the occipital lateral mesoderm and ectoderm. Thus, we have discovered evolutionarily conserved morphogenetic movements, driven by the occipital lateral mesoderm and ectoderm, that ensure cell transport and organ assembly at the head-trunk interface.