Genetic analysis of three lactate dehydrogenase isozyme systems in trout: Evidence for linkage of genes coding subunits A and B

Abstract

Lactate dehydrogenase (LDH) isozymes of two genera within the family Salmonidae (Salvelinus and SaZnLo) were examined by acrylamide and starch gel electrophoresis. Those species examined contain three isozyme series involving five different kinds of subunits. The A-Is series, believed to be homologous to LDH 1-5 in the majority of vertebrates, is found in nearly all tissues. Polymorphism for subunit B was discovered in Salvelinus fontinalis in which two kinds, B and B , are present within a number of inbred strains. Various crosses and backcrosses involving S. fontinalis and Salvelinus namaycush demonstrate that subunits A and B are each coded by different autosomal genes (LA and LB). A limited amount of testcross data indicates linkage of these genes. Partial genetic analysis indicates that a second series of several LDH isozynies, largely restricted to the retina, involves a third subunit, C, in combination with B and to a lesser extent with A. A variant form of subunit C was found in Salmo trutta. Comparison of patterns of S. fontinalis and S . trutta and their hybrid seems to indicate that two additional subunits are involved in a third series of five isozymes found in the skeletal muscle of each species examined.

Genetic analysis of enzyme polymorphisms in plaice (Pleuronectes platessa)

“…These data, however, refer to sex-linked loci controlling secondary sexual characters and may not be representative of autosomal situations. Morrison and Wright (1966) report linkage between two lactate dehydrogenase loci in Salvelinus hybrids with recombination of about 15 per cent. Similarly, in segregation analyses using hybrids of Lepomis in which the parents showed differing mobilities for homologous enzymes, Wheat et al (1973) reported linkage between G3PDH and 6-phosphogluconate dehydrogenase with 15-22 per cent recombination.…”

Lactate dehydrogenase ontogeny, paternal gene activation, and tetramer assembly in embryos of brook trout, lake trout, and their hybrids

“…genes is presumably autosomal (Goldberg, 1966;Morrison and Wright, 1966), F 1 splake have the LDH genotype AA'BB, with A and A' acting as co-dominant alleles. These hybrids contain, in effect, three classes of polypeptide subunits coded at the A and B loci (i.e., A, A', and B), so that there are 15 isozymes which can be formed in this system.…”

“…Reciprocal crosses were used to relate paternal gene activation with developmental stage. In addition, activation of the gene coding for the LDH subunit confined to the retina of trout, as well as of certain other fish eyes (Markert and Faulhaber, 1965;Goldberg, 1966;Morrison and Wright, 1966), was measured.…”

Effects of glucose-containing peritoneal-dialysis solutions on rates of lipogenesis in vivo in the liver, brown and white adipose tissue of chronic uraemic rats

“…They were maintained on a chow diet (PRM diet; E. Dixon and Sons Ltd., Ware, Herts., U.K.) and water ad libitum in an animal house with lights on from 08:00 to 20:00h. Chronic uraemia was induced by the five-sixths bilateral-nephrectomy technique (Morrison, 1966). Uraemic rats were allowed approx.…”