Presentation description

Atrial fibrillation (AF), a cardiac arrhythmia characterized by erratic quivering of the atria, affects approximately 6 million people per year. A subset of atrial fibrillation is familial, whereby several family members present with young-onset AF, with a strong hereditary component. Our lab has identified a novel mutation (M527L) in the Nuclear Factor of Activated T-cells 1 (NFATc1) that segregates with the AF phenotype in a small family, making it a novel candidate gene to study AF susceptibility. Although it is known that NFATc1 is expressed in the heart, there is less information about its expression in specific cell types during development. Our objective is to study nfatc1 expression in the zebrafish heart. We used a Fluorescent In Situ Hybridization (FISH) kit (Molecular Instruments) and confocal microscopy to localize nfatc1 expression at the mRNA level in the embryonic (24-120 hours post fertilization) zebrafish heart. We compared zebrafish embryos with and without 1-phenyl 2-thiourea (PTU) treatment (to inhibit pigmentation and improve optical transparency). Proteinase K optimization protocol showed ideal conditions depended on embryonic age and PTU vs. non-PTU treatment. We found in the heart of 72hpf embryos (30 ug/ml Proteinase K treatment for 45' at 37C) a faint positive nfatc1 signal colocalizing with a cardiomyocyte marker (cmcl2-GFP) in both the PTU and non-PTU treated embryos. Future experiments include repeating the experiment in different embryo ages and the juvenile zebrafish heart. This information will be greatly valuable in understanding AF risk factors, patient susceptibility, and eventually lead to personalized treatments.