Advanced cardiac morphogenesis does not require heart tube fusion.
The bilateral cardiac mesoderm migrates from the lateral region of the embryo to the ventral midline, where it fuses to form the primitive heart tube. It is generally accepted that migration and fusion are essential for subsequent stages of cardiac morphogenesis. We present evidence that, in Foxp4 mutant embryonic mice, each bilateral heart-forming region is capable of developing into a highly differentiated four-chambered mammalian heart in the absence of midline fusion. These data demonstrate that left-right chamber specification, cardiac looping, septation, cardiac myocyte differentiation, and endocardial cushion formation are preprogrammed in the precardiac mesoderm and do not require midline positional identity or heart tube fusion.
Li
Shanru
S
Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Zhou
Deying
D
Lu
Min Min
MM
Morrisey
Edward E
EE
D000818:Animals; D017209:Apoptosis; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins; D019521:Body Patterning; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004699:Endocardium / Q000196:embryology; D004707:Endoderm / Q000166:cytology / Q000378:metabolism; D051858:Forkhead Transcription Factors; D018390:Gene Targeting; D006321:Heart / Q000196:embryology*; D006325:Heart Atria / Q000196:embryology; D006352:Heart Ventricles / Q000196:embryology; D017403:In Situ Hybridization; D008648:Mesoderm / Q000502:physiology; D051379:Mice; D009024:Morphogenesis; D009154:Mutation; D032383:Myocytes, Cardiac / Q000166:cytology*; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D029961:Zebrafish Proteins
D009320:Atrial Natriuretic Factor; D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D051858:Forkhead Transcription Factors; D016271:Proto-Oncogene Proteins c-myc; D014157:Transcription Factors; D029961:Zebrafish Proteins; C472854:Foxp4 protein, mouse; C095572:Hand1 protein, mouse; C498766:Hand2 protein, mouse; C410915:hand2 protein, zebrafish; C097341:helix-loop-helix protein, eHAND