CARDIAC MYOSIN BINDING-PROTEIN-C GENE IS SPECIFICALLY EXPRESSED IN HEART DURING MURINE AND HUMAN-DEVELOPMENT

Cardiac myosin binding protein C (MyBP-C) is a substantial component o f the sarcomere, with both structural and regulatory roles. The gene e ncoding cardiac MyBP-C in humans is located on chromosome 11p11.2, and mutations that are most predicted to produce truncated proteins have been identified in this gene in unrelated families with familial hyper trophic cardiomyopathy (FHC). To understand better the pathophysiology of FHC and with a view to the development of animal models for this d isease, we have investigated by in situ hybridization the pattern of e xpression of the cardiac MyBP-C gene during human and mouse developmen t using species-specific oligonucleotide probes. From 4 weeks of human development, a strong labeling of cardiac MyBP-C mRNAs was unambiguou sly detected in all heart compartments, and no signal could be visuali zed in somites. In murine embryos, from embryonic day 9.5 until birth, a strong signal was detected exclusively in the heart, Our results sh owed that during both human and murine development, in contrast to chi cken development, the cardiac MyBP-C gene is abundantly and specifical ly expressed in the heart.