Jack S. Frankel

Lactate dehydrogenase isozymes of the leopard danio, Brachydanio nigrofasciatus: their characterization and ontogeny

Abstract 1. 1. The tissue specific patterns and ontogeny of lactate dehydrogenase (LDH) are reported. 2. 2. While all tissues (eye, brain, heart, intestine, liver, ovary and skeletal muscle) show isozymes of A and B subunit composition, only liver extracts possess isozymes resulting from C subunit synthesis. 3. 3. The A 4 homopolymer appears simultaneously with initial muscle contractility and is correlated with the physiological function of muscular contraction. 4. 4. The activation of the Ldh-C locus is correlated with the first functioning of liver. It is suggested that the state of differentiation of liver cells may be the stimulus required for C locus expression.

Lactate dehydrogenase isozymes of the island barb, Barbus oligolepis (Cypriniformes, Teleostei): their characterization and ontogeny

Abstract 1. 1. The tissue specificity, preferential susceptibility to urea inactivation and ontogeny of lactate dehydrogenase in the Island barb, Barbus oligolepsis , are reported. 2. 2. All tissues exhibit isozymes of A and B subunit composition. However, only liver extracts show isozymes resulting from the expression of the Ldh-C locus. 3. 3. The LDH isozymes of the Island barb exhibit a hierarchy of susceptibility to inactivation by urea of A 4 B 4 C 4 ; consistent with findings for cyprinid fishes. 4. 4. The A 4 isozyme appears simultaneously with the first muscular contractions of the developing embryo. Its appearance is most probably the result of, or impetus for, muscle cell differentiation. 5. 5. The activation of the Ldh-C locus is correlated with the depletion in yolk during B. oligolepis development. The appearance of isozymes of C subunit-composition in Barbus is apparently closely tied to the state of liver cell differentiation.

Ontogenetic patterns of enzyme locus expression in Barbus hybrids (Cypriniformes, Teleostei)

The tissue specific patterns and ontogeny of sorbitol dehydrogenase (SDH, EC 1.1.1.14). lactate dehydrogenase (LDH, EC 1.1.1.27) and isocitrate dehydrogenase (IDH, EC 1.1.1.42) are reported for Barbus tetrazona (tiger barb), B. conchonius (rosy barb), B. nigrofasciatus (black ruby barb), B. titteya (cherry barb), B. sachsi (gold barb), and in interspecific hybrids where B. tetrazona is the maternal parent. The spatial and temporal expression of SDH, LDH and IDH isozymes in Barbus is consistent with those reported for other teleosts. As the genetic distance between the parentals used in forming the hybrid increases, allelic expression proceeds from synchronous to asynchronous, with an increasing delay in embryonic gene expression. These observations are consistent with the hypothesis that parental sensor genes differ in their response to maternally controlled regulatory signals; indicative of species specific effector/activator RNA molecule concentrations and sensor/receptor gene induction thresholds.

Comparison of the spatial and temporal expression of supernatant malate dehydrogenase in Barbus hybrids (Cypriniformes, Teleostei)

The tissue specificity and ontogeny of supernatant malate dehydrogenase (s-MDH) are reported for the tiger barb, cherry barb, and their reciprocal hybrids. The tissue distribution of s-MDH isozymes in Barbus is consistent with the patterns reported in other teleosts. The expression of the Mdh-B locus is correlated with the initial muscle contractions of the developing embryos. It is suggested that the state of muscle cell differentiation may be the stimulus necessary for the expression of this locus in Barbus. Expression of maternal and paternal alleles at the B locus are synchronously delayed in reciprocal hybrids, as compared to their expression intraspecifically.

Lactate dehydrogenase tissue specificity and characterization in the teleost genus Barbus

Abstract 1. 1. The tissue specific patterns of lactate dehydrogenase (LDH) for four species of Barbus are reported. 2. 2. While all tissues (eye, brain, heart, intestine, liver, ovary, skeletal muscle and stomach) show isozymes of A and B subunit composition, only liver extracts possess isozymes resulting from C subunit synthesis. 3. 3. The relative susceptibility of Barbus LDH isozymes to inactivation by urea is similar to the hierarchy of susceptibility observed for these isozymes in other teleosts. 4. 4. In vitro hybridization of liver isozymes suggests that the restriction on LDH subunit assembly in Barbus is the result of spatial and/or temporal isolation of subunit synthesis.

Alcohol dehydrogenase ontogeny and liver maturation in the leopard danio, brachydanio nigrofasciatus

1. 1. The tissue specificity and ontogeny of alcohol dehydrogenase (ADH) are reported for the leopard danio, Brachydanio nigrofasciatus. 2. 2. Of the seven adult tissues assayed (eye, brain, kidney, liver, ovary, skeletal muscle and stomach), only liver extracts showed ADH activity. 3. 3. The activation of the Adh locus is correlated with the first functioning of liver. It is suggested that the state of liver cell differentiation may be the stimulus necessary for Adh locus expression.

Asynchronous expression of the alcohol and supernatant malate dehydrogenase loci during Barbus hybrid development (Cypriniformes, Teleostei).

The tissue specificity and ontogeny of supernatant malate dehydrogenase (s-MDH) and alcohol dehydrogenase (ADH) are reported for the tiger barb (Barbus tetrazona), the rosy barb (Barbus conchonius) and their reciprocal hybrids. The tissue distribution of s-MDH and ADH isozymes in both species is consistent with spatial profiles reported for other teleosts. The expression of alleles of paternal origin at the s-Mdh-B and Adh loci are delayed in reciprocal hybrids as compared to their expression intraspecifically; suggestive of a low degree of affinity between maternally derived regulatory factors and paternal regulative elements controlling structural gene activation.

Aberrant gene expression at the creatine kinase loci during Barbus hybrid development (cypriniformes, teleostei)

The tissue specificity and ontogeny of creatine kinase (CK, EC 2.7.3.2) are reported for tiger, rosy, ruby, cherry and gold barbs, and in interspecific hybrids where the tiger barb is the maternal parent. The spatial expression of CK isoenzymes in Barbus is consistent with the tissue patterns reported in other teleosts. In general, as the taxonomic (genetic) distance between the parental species increases, a corresponding delay in embryonic gene expression occurs; suggestive of species-specific effector molecule/sensor gene induction thresholds.

Comparative analysis of lactate dehydrogenase isozymes in neural tissues of Poecilia (Poeciliidae)

Abstract 1. 1. The tissue specific patterns of lactate dehydrogenase (LDH) of brain and eye in three species of Poecilia are reported. 2. 2. While all tissues (diencephalon, mesencephalon, optic nerve, metencephalon, myelencephalon and eye) exhibit high A 4 and B 4 isozyme activity, heteropolymers of A and B subunit composition are lacking. 3. 3. The activity of the C 4 homopolymer is observed to predominate in extracts of mesencephalon and eye. 4. 4. Restricted assembly of C subunit-containing isozymes in specific neural tissues is apparently the result of spatial and/or temporal isolation of C and A, or C and B subunits. Where all three subunits are simultaneously accessible to each other, it is suggested that they form CAB heterotetramers due to the presence of the C subunit in the tetramer.

Serum esterase variation and characterization in populations of the longnose garpike, Lepisosteus osseus☆

Abstract 1. 1. Serum esterase variation in populations of Lepisosteus osseus, sampled from North and South Carolina, was investigated employing acrylamide gel electrophoresis. 2. 2. North Carolina populations were found to be monomorphic with respect to serum esterase activity. 3. 3. All South Carolina populations proved to be polymorphic; each individual sampled from these populations possessed one of two phenotypic profiles. 4. 4. Serum esterases were characterized utilizing eserine sulfate, diisopropylfluorophosphate, and sulfhydryl-group inhibitors.