Please note that we have stopped the regular imports of Gene Expression Omnibus (GEO) data into ArrayExpress. This may not be the latest version of this experiment.
E-GEOD-23381 - Transcription profile of zebrafish hand2 (hanS6 allele) mutant embryos at 19hpf
Released on 3 August 2010, last updated on 27 March 2012
Heart formation requires the fusion of bilateral cardiomyocyte populations as they move toward the embryonic midline. The bHLH transcription factor Hand2 is essential for cardiac fusion; however, the effector genes that execute this function of Hand2 are unknown. Here, we provide the first evidence for a downstream component of the Hand2 pathway that mediates cardiac morphogenesis. Although hand2 is expressed in cardiomyocytes, mosaic analysis demonstrates that hand2 plays a non-autonomous role in regulating cardiomyocyte movement. Gene expression profiles reveal heightened expression of fibronectin 1 (fn1) in hand2 mutant embryos. Reciprocally, overexpression of hand2 leads to decreased Fibronectin levels. Furthermore, reduction of fn1 function enables rescue of cardiac fusion in hand2 mutants: bilateral cardiomyocyte populations merge and exhibit improved tissue architecture, albeit without major changes in apicobasal polarity. Together, our data provide a novel example of a tissue creating a favorable environment for its morphogenesis: the Hand2 pathway establishes an appropriate environment for cardiac fusion through negative modulation of Fn1 levels. Embryos from three independent hand2 mutant (hanS6 allele) heterozyogous crosses were collected. Examination of Tg(myl7:egfp) expression allow sorting of hand2 mutant embryos from their wild-type siblings.
transcription profiling by array
Zayra Viviana Garavito-Aguilar <firstname.lastname@example.org>, Deborah Yelon, Zayra V Garavito-Aguilar
Hand2 ensures an appropriate environment for cardiac fusion by limiting Fibronectin function. Garavito-Aguilar ZV, Riley HE, Yelon D. , PMID:20724450