A genetically determined variant of the A-subunit of lactic dehydrogenase in the deer mouse

Heterozygosity and gene flow in populations of Calomys laucha (Rodentia, Cricetidae)

Enzyme polymorphism was studied by means of starch gel electrophoresis on five population samples of Calomys laucha collected in different sites and seasons. C. laucha, a cricetid rodent inhabiting preferentially cultivated fields in the central-eastern plains of Argentina, is a reservoir-host of Junin virus, agent of Argentine hemorrhagic fever. Results show high levels of genic variability in all the samples (P from 62.50 to 77.27; H from 0.118 to 0.163) and low genetic distance among populations (D from 0.0024 to 0.0167). Estimations of gene flow (mean Nm = 10.78) indicate a high migration capability of the species and the possibility of further dispersal of Junin virus.

A mutation affecting the lactate dehydrogenase locus Ldh-1 in the mouse-I. Genetical and electrophoretical characterization

(101/El x C3H/el)F1 male mice were infected intraperitoneally with the mutagen procarbazine hydrochloride and immediately caged with untreated test-stock females. Crude liver extracts from the offspring were subjected to polyacrylamide gel isoelectric focusing, and the gels were stained for six enzymes. In the experimental group (mutagen treated spermatogonial germ-cell stage), a dominant inherited banding alteration of the lactate dehydrogenase (LDH) pattern was detected. By crossing the heterozygous mutants, homozygotes were obtained that showed much less gel staining intensity. The mutation is codominantly expressed with 100% penetrance. The banding alteration was also observed in muscle, kidney, heart, blood, brain, testis, spleen, and lung. Polyacrylamide gel electrophoresis was performed with all the tissues examined. The mutation causes the intensity of the band corresponding to LDH-A (primary molecular form in muscle) to decrease from that of the wild type, while the intensity of the bands corresponding to LDH-B (primary molecular form in heart) remains constant. It is concluded that the mutation affects the locus coding for LDH of the muscle type. Ldh-1c is proposed as the allele symbol.