title: Identification and localization of TBX5 transcription factor during human cardiac morphogenesis.
abstract: Mutations in the TBX5 transcription factor gene cause human cardiac malformation in Holt-Oram syndrome. To identify and localize TBX5 during cardiac morphogenesis, we performed immunohistochemical studies of TBX5 protein cardiac expression during human embryogenesis. Specific antibody to human TBX5 was generated in rabbits with a TBX5 synthetic peptide and affinity purification of antiserum. Anti-TBX5 was used in immunohistochemical analyses of human cardiac tissue. In embryonic and adult heart, TBX5 is expressed throughout the epicardium and in cardiomyocyte nuclei in myocardium of all four cardiac chambers. Endocardial expression of TBX5 is only present in left ventricle. Asymmetric left-sided transmyocardial gradients of TBX5 protein expression were observed in embryonic but not adult hearts. Human cardiac expression of TBX5 protein correlates with the cardiac manifestations of Holt-Oram syndrome. TBX5 transmyocardial protein gradients may contribute to normal patterning of the human heart during embryogenesis.
authors.affiliation: Cardiology Division, Department of Medicine and Department of Cell Biology, Weill Medical College of Cornell University, New York, New York 10021, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Hatcher
authors.forename: M M
authors.initials: MM
authors.lastname: Goldstein
authors.forename: C S
authors.initials: CS
authors.lastname: Mah
authors.forename: C S
authors.initials: CS
authors.lastname: Delia
authors.forename: C T
authors.initials: CT
authors.lastname: Basson
mesh_terms: D000328:Adult; D000818:Animals; D015153:Blotting, Western; D004622:Embryo, Mammalian / Q000378:metabolism*; D005314:Embryonic and Fetal Development; D004699:Endocardium / Q000737:chemistry; D005318:Fetal Heart / Q000737:chemistry*; D018507:Gene Expression Regulation, Developmental; D006330:Heart Defects, Congenital / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D009024:Morphogenesis; D009206:Myocardium / Q000737:chemistry* / Q000166:cytology; D010496:Pericardium / Q000737:chemistry; D011817:Rabbits; D011993:Recombinant Fusion Proteins; D020825:T-Box Domain Proteins / Q000032:analysis* / Q000235:genetics / Q000276:immunology
chemical_list: D011993:Recombinant Fusion Proteins; D020825:T-Box Domain Proteins; C103172:T-box transcription factor 5