Endoderm contributes to endocardial composition during cardiogenesis

Heart formation commences from a single heart tube,which fuses from bilateral primordial heart fields.The developing heart tube is composed of outer-layer myocardial cells and inner-layer endocardial cells.Several distinct populations of precardiac cells contribute to cardiac morphogenesis.However,it still remains not very clear about the lineage of endocardium at gastrulation stage.Thereby,this study focused on ascertaining the correlation between the hypoblast in gastrulation and endocardium during cardiogenesis.Firstly,the fusing heart tube morphologically is closed to endoderm-derived pharynx floor,implying the possibility that pharynx floor might be wrapped into the formation of endoderm.Secondly,HNK1 is expressed in hypoblast strongly at gastrula stage and subsequently appeared in endocardium of cardiogenesis.Moreover,fate map data displayed that DiI labeled hypoblast was also present in endocardium later on.One more evidence is chick-quail chimera of hypoblast transplantation,in which quail-hypoblast derivative could be identified inendocardium of cardiogenesis by QCPN antibody.In sum,our current data suggests that endoderm in gastrula contribute at least partly to the formation of endocardium of cardiogenesis.

Combinational electroporation and transplantation approach to studying gene functions in avian embryos

Gene transfection is an indispensable approach for studying gene function since it provides important information on gain-and/or loss-of-function.Chick embryos are also extensively employed for studying biological function since they are easily accessible and can be maintained alive after manipulation.The combination of both techniques presents a powerful approach to understanding how genes regulate embryo development.Furthermore,combining these approaches with tissue transplant techniques make even more attractive for elucidate gene function.Electroporation,employing parallelly fashioned electrodes,has been widely used in chick embryos.However,experimenters have been frustrated by unsuccessfully transfection in some embryonic tissue of interest because the electrodes were improperly positioned.We presently demonstrated the different patterns of organizing and positioning the electrodes,in combination with tissue transplantation,to efficiently and specifically transfect the chick embryonic head,trunk neural tube,heart tube,somites and neural crest cells with the GFP reporter gene.