Predicted to enable actin monomer binding activity and calcium ion binding activity. Involved in heart development and positive regulation of the force of heart contraction. Acts upstream of or within several processes, including cardiac muscle contraction; heart development; and muscle cell fate specification. Located in myofibril. Is expressed in several structures, including diaphragm; embryo mesoderm; eye; heart; and triceps surae muscle. Human ortholog(s) of this gene implicated in familial hypertrophic cardiomyopathy and hypertrophic cardiomyopathy 10. Orthologous to human MYL2 (myosin light chain 2). [provided by Alliance of Genome Resources, Apr 2022]