We characterized the first POU-homeoprotein in a crustacean (designated APH-1 for Artemia POU-Homeoprotein, EMBL Y15070). The amino acid sequence of the APH-1 POU-domain is identical, except for two residues, to that of the two class III POU proteins Cf1-a (Drosophila) and POU-M1 (Bombyx mori). Southern blot analysis suggests that crustaceans have only one class III POU gene. RT-PCR and whole-mount in situ hybridization show that APH-1 mRNA is present in larvae specifically in the salt gland, an organ which is involved in osmoregulation, and disappears in the adult.
Chavez, M., Landry, C., Loret, S., Muller, M., Figueroa, J., Peers, B., Rentier-Delrue, F., Rousseau, G., Krauskopf, M., & Martial, J. A. (1999). APH-1, a POU homeobox gene expressed in the salt gland of the crustacean Artemia franciscana. Mechanisms of Development, 87(1-2), 207-212. https://doi.org/10.1016/S0925-4773(99)00152-5 (Original work published 1999)