Popeye domain containing gene 2 (Popdc2) is a myocyte-specific differentiation marker during chick heart development.
The Popeye domain containing (popdc) genes constitute a novel gene family encoding proteins of the plasma membrane in muscle cells, with three N-terminal transmembrane domains and a cytoplasmic carboxy terminus. In vertebrates, three members of the Popdc gene family have been described. However, in the chick system only two cDNAs, Popdc1 and Popdc3, have been cloned previously. By screening a chick expressed sequence tag database, we report here the identification of five alternatively spliced chick Popdc2 cDNAs with different carboxy termini. Northern blot analysis revealed expression of Popdc2 predominantly in the myocardium and weaker expression in skeletal muscle. By whole-mount in situ hybridization, chick Popdc2 was first detected at Hamburger and Hamilton (HH) stage 7 within the anterior part of the heart fields. In the tubular heart, atrial and ventricular precursor cells stained positively for Popdc2. Weaker expression was observed in myocardium of the outflow tract and sinus venosus. By HH stage 18, the outer curvature myocardium was strongly stained, whereas expression in myocardium of the inner curvature was negligible. Popdc2 expression was absent from the endocardium and propepicardial organ. At HH stage 36, Popdc2 expression was confined to the compact layer myocardium. In addition to the heart, Popdc2 expression was also observed in the myotome and in the muscle-forming fields of the limbs. Our results indicate that Popdc2 is highly expressed in the developing heart and may serve as a novel marker of myocardial differentiation in the chick embryo.
Department of Cell and Molecular Biology, Institute of Biochemistry and Biotechnology, Technical University of Braunschweig, Braunschweig, Germany.
Stephanie S
SS
Breher
Eleftheria
E
Mavridou
Christian
C
Brenneis
Alexander
A
Froese
Hans-Henning
HH
Arnold
Thomas
T
Brand
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins; D015152:Blotting, Northern; D015815:Cell Adhesion Molecules / Q000378:metabolism / Q000502:physiology*; D002454:Cell Differentiation; D002642:Chick Embryo; D003001:Cloning, Molecular; D019295:Computational Biology; D018076:DNA, Complementary / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006321:Heart / Q000196:embryology*; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D032342:Muscle Cells / Q000378:metabolism*; D009124:Muscle Proteins / Q000378:metabolism / Q000502:physiology*; D009206:Myocardium / Q000378:metabolism; D010802:Phylogeny; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014018:Tissue Distribution
D030161:Avian Proteins; C498788:Bves protein, Gallus gallus; D015815:Cell Adhesion Molecules; D018076:DNA, Complementary; D009124:Muscle Proteins; D020033:Protein Isoforms