The present invention relates to an isolated .beta.-actin nucleic acid promoter molecule from shrimp; nucleic acid constructs including the .beta.-actin promoter molecule; and expression vectors, host cells, and transgenic animals transduced with the isolated .beta.-actin nucleic acid promoter. Also disclosed are methods for imparting to an animal resistance against a pathogen, regulating growth of an animal, increasing stress tolerance in an animal, and increasing cold tolerance in an animal that involves transforming an animal with a nucleic acid construct including the isolated .beta.-actin nucleic acid promoter molecule of the present invention.