hes1 is expressed in the second heart field and is required for outflow tract developmenthes1表示在第二心脏领域和流出道的发展需要.pdfVIP

Hes1 Is Expressed in the Second Heart Field and Is Required for Outflow Tract Development 1. 1. 1 ´ ` 1 ` 2 Francesca Rochais , Mathieu Dandonneau , Karim Mesbah , Therese Jarry , Marie-Genevieve Mattei , Robert G. Kelly1* ´ ´ ´ ´ 1 Developmental Biology Institute of Marseilles-Luminy, UMR 6216 CNRS-Universite de la Mediterranee, Campus de Luminy, Marseille, France, 2 Inserm UMR 910, Faculte ´ ˆ de Medecine, Hopital d’Enfants de la Timone, Marseille, France Abstract Background: Rapid growth of the embryonic heart occurs by addition of progenitor cells of the second heart field to the poles of the elongating heart tube. Failure or perturbation of this process leads to congenital heart defects. In order to provide further insight into second heart field development we characterized the insertion site of a transgene expressed in the second heart field and outflow tract as the result of an integration site position effect. Results: Here we show that the integration site of the A17-Myf5-nlacZ-T55 transgene lies upstream of Hes1, encoding a basic helix-loop-helix containing transcriptional repressor required for the maintenance of diverse progenitor cell populations during embryonic development. Transgene expression in a subset of Hes1 expression sites, including the CNS, pharyngeal epithelia, pericardium, limb bud and lung endoderm suggests that Hes1 is the endogenous target of regulatory elements trapped by the transgene. Hes1 is expressed in pharyngeal endoderm and mesoderm including the second heart field.