title: Left-asymmetric expression of Galanin in the linear heart tube of the mouse embryo is independent of the nodal co-receptor gene cryptic.
abstract: Only very few left/right asymmetrically expressed genes are known in the mammalian embryo. In a screen for novel factors we identified the gene encoding the neuropeptide Galanin in mouse. At embryonic day (E) 8.5 asymmetric mRNA transcription was found in the left half of the linear heart tube. During heart looping and morphogenesis expression became restricted to the atrio-ventricular (AV) canal, followed by specific staining of the AV-node and AV-rings in the four-chambered heart. Expression was inverted in inv/inv and randomized in homozygous iv mutant embryos. Left-sided heart-specific transcription of mouse Gal thus should be controlled by the left-right pathway. The asymmetric pattern was retained in cryptic mutant embryos, in which the Nodal signaling cascade is disrupted. Surprisingly, Pitx2c was found to be expressed in 50% of cryptic mutant hearts as well, suggesting that some aspects of asymmetric gene expression in the heart are independent of cryptic.
authors.affiliation: University of Hohenheim, Institute of Zoology, Stuttgart, Germany. schweick@uni-hohenheim.de
authors.forename: Axel
authors.initials: A
authors.lastname: Schweickert
authors.forename: Kirsten
authors.initials: K
authors.lastname: Deissler
authors.forename: Stefan
authors.initials: S
authors.lastname: Britsch
authors.forename: Miriam
authors.initials: M
authors.lastname: Albrecht
authors.forename: Heike
authors.initials: H
authors.lastname: Ehmann
authors.forename: Verena
authors.initials: V
authors.lastname: Mauch
authors.forename: Ursula
authors.initials: U
authors.lastname: Gaio
authors.forename: Martin
authors.initials: M
authors.lastname: Blum
mesh_terms: D000818:Animals; D019521:Body Patterning; D001921:Brain / Q000196:embryology / Q000378:metabolism; D019004:Galanin / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D006321:Heart / Q000196:embryology*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D009206:Myocardium / Q000378:metabolism*; D055457:Nodal Protein / Q000378:metabolism; D014982:Xenopus laevis / Q000196:embryology / Q000378:metabolism
chemical_list: C104433:Cfc1 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D055457:Nodal Protein; D019004:Galanin