title: Experimental study of the development of the truncus arteriosus of the chick embryo heart. I. Time of appearance.
abstract: The time of appearance of the truncus arteriosus was studied in the chick embryo using an in ovo labeling technique. Three hundred embryos at stages 13-18 of Hamburger and Hamilton were selectively labeled at the distal end of the heart tube, using gelatine-india ink label; 122 of these embryos were reincubated and 111 of them reached stages 25-28. In these stages the final location of the label was determined. Only 95 of these embryos showed both a normal heart and a label located in it. The remaining embryos were discarded due to abnormal cardiac morphology or because the label was not found. Embryos labeled at stages 13-14 had label in the conus in 42.8% of the cases and in the boundary between the conus and the truncus arteriosus in 57.1% of the cases. Label placed at stages 15-16 was located in the conus in 6.1% of the cases, in the boundary between the conus and the truncus arteriosus in 44.8% of the cases, and in the truncus arteriosus in 48.9% of the cases. Finally, label placed at stages 17-18 was located in the boundary between the conus and the truncus arteriosus in 18.7% of the cases and in the truncus arteriosus in 81.2% of the cases. Our results permit us to conclude that the truncus arteriosus appears in the chick embryo as early as stages 15-16 of Hamburger and Hamilton (50-56 hours of incubation).
authors.affiliation: Department of Histology, Facultad de Medicina U.N.A.M., México, D.F.
authors.forename: I
authors.initials: I
authors.lastname: Garcia-Peláez
authors.forename: M
authors.initials: M
authors.lastname: Arteaga
mesh_terms: D000818:Animals; D002642:Chick Embryo; D005314:Embryonic and Fetal Development; D006321:Heart / Q000033:anatomy & histology / Q000196:embryology*; D013997:Time Factors; D014338:Truncus Arteriosus / Q000033:anatomy & histology / Q000196:embryology*