Isozyme distribution of ten enzymes and their loci in South American lungfish, Lepidosiren paradoxa (Osteichthyes, Dipnoi)

Scarce bibliographical data exists on the enzymes in Lepidosiren paradoxa a nd analysis of several enzymes was considered worthy of investigation. Dist ribution of ADH, ALP, FBALD, GAPDH, G3PDH, G6PDH, GPI, LDH, MDH, and PGM wa s identified in ten tissues (retina, heart, muscle, liver, kidney, lung, gu t, gills, brain, and ovary) of the South American lungfish and compared wit h patterns previously described in other vertebrates. Compared with earlier results differences in the number of loci expressed were observed for ADH, G3PDH, GPI, and MDH. The number of loci expressed and/or in tissue specifi city of several enzymes (ADH, FBALD, GAPDH, G3PDH, G6PDH and PGM) were foun d to be similar to those of other vertebrates. Differences were detected in ALP due to the absence of an intestinal-specific form typical of fish, amp hibians, reptiles and birds: further differences were observed in GPI and M DH due to their tissue expression. The differences in LDH involve the LDH-A (4) isozyme which was most common in tissues. Overall, comparison with othe r vertebrates reveals that in L. paradoxa the tissue-restricted expressions of some enzymes are similar, while others have retained an ancestral patte rn and exhibit a more widespread tissue expression of genes, (C) 2000 Elsev ier Science Inc. All rights reserved.