Expression of Centa2 and Suz12 during mammalian heart development

Cardiovascular malformations (CVMs) have a higher incidence in patients with NF1 microdeletion syndrome, compared to classical NF1 patients, presumably owing to haploinsufficiency of the genes lying in the deletion interval. Searching for CMVs candidate genes inside the deletion, we focused our attention on three genes, CENTA2, SUZ12 AND UTP6. Whole mount in situ hybridization (WISH) on mouse embryos showed high expression of Centa2 in heart at 9-10 dpc, and of Suz12 in the atrium around 10 dpc, suggesting their involvement in heart development and CVMs onset. RT-PCR analysis on zebrafish embryos showed Centa2 and Suz12 expression in oocytes and throughout all the analyzed stages (8 cells-120 hpf). Centa2, but not Suz12 was also present in adult heart. We thus carried out WISH experiments on zebrafish embryos to characterize Canta2/Suz12 spatio-temporal expression profiles. At 24 hpf we observed a diffuse Centa2 specific hybridization signal in the cephalic and medial portion of the embryo, which becomes stronger starting from 48 hpf. At 48-72 hpf Centa2 is also expressed in liver and pectoral fin bud. We observed a weak signal in the bulbus arteriosus at 48-72 hpf, but not in the remaining heart portions. Suz12 shows an intense hybridization signal in the medial and rostral region of the embryo at 30-72 hpf, but no expression in the heart. Considering that zebrafish heart has two chambers, we speculate that Centa2 and Suz12 might be important for cardiac morphogenesis in the most evoluted organisms, such as mammals, which have a four-chambered heart.