title: Second heart field and the development of the outflow tract in human embryonic heart.
abstract: The second heart field (SHF) is indicated to contribute to the embryonic heart development. However, less knowledge is available about SHF development of human embryo due to the difficulty of collecting embryos. In this study, serial sections of human embryos from Carnegie stage 10 (CS10) to CS16 were stained with antibodies against Islet-1 (Isl-1), Nkx2.5, GATA4, myosin heavy chain (MHC) and α-smooth muscle actin (α-SMA) to observe spatiotemporal distribution of SHF and its contribution to the development of the arterial pole of cardiac tube. Our findings suggest that during CS10 to CS12, SHF of the human embryo is composed of the bilateral pharyngeal mesenchyme, the central mesenchyme of the branchial arch and splanchnic mesoderm of the pericardial cavity dorsal wall. With development, SHF translocates and consists of ventral pharyngeal mesenchyme and dorsal wall of the pericardial cavity. Hence, the SHF of human embryo shows a dynamic spatiotemporal distribution pattern. The formation of the Isl-1 positive condense cell prongs provides an explanation for the saddle structure formation at the distal pole of the outflow tract. In human embryo, the Isl-1 positive cells of SHF may contribute to the formation of myocardial outflow tract (OFT) and the septum during different development stages.
authors.affiliation: Department of Histology and Embryology, Shanxi Medical University, 56 Xin Jian Nan Road, Taiyuan, 030001, Shanxi, China.
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Yang
authors.forename: Hai-Rong
authors.initials: HR
authors.lastname: Li
authors.forename: Xi-Mei
authors.initials: XM
authors.lastname: Cao
authors.forename: Qin-Xue
authors.initials: QX
authors.lastname: Wang
authors.forename: Cong-Jin
authors.initials: CJ
authors.lastname: Qiao
authors.forename: Jing
authors.initials: J
authors.lastname: Ya
mesh_terms: D005260:Female; D050991:GATA4 Transcription Factor / Q000378:metabolism; D006321:Heart / Q000196:embryology*; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D060850:LIM-Homeodomain Proteins / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000378:metabolism; D011247:Pregnancy; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D050991:GATA4 Transcription Factor; D060850:LIM-Homeodomain Proteins; D014157:Transcription Factors; C063843:insulin gene enhancer binding protein Isl-1; D018995:Myosin Heavy Chains