Three genes (A, B, and E) encoding lactate dehydrogenase (LDH) subunits are shown to be present in fish by: (1) molecular hybridization, (2) allelic variants at two loci, and (3) kinetic, physical, and immunochemical studies. The same studies reveal that the E4 isozyme is closely related to the B4 isozyme. The E4 isozyme is usually synthesized in the regions of the nervous system concerned with vision. However, in some species the E4 isozyme is found in non‐neural tissues such as lens. The closely related B and E loci tend to simulataneously functional in the same retinal cells. The act of hatching by itself does not appear to act as the stimulus to E gene activation. The E subunit facilitates the assembly of A and B subunits into the same teramer. The developmental and tissue specificity of the function of the LDH E gene suggests that the distinctive physical properties and the kinetic behavior of the LDH E4 isozyme may play an important role in the metabolism of teleost vision.
ASJC Scopus subject areas
- Animal Science and Zoology