Genetic control of enzyme polymorphisms in the california vole, Microtus californicus

Inheritance of 15 polymorphic isozymes was investigated in captive Microtus californicus. Eleven of the isozymes show patterns consistent with a Mendelian model of inheritance: glycerol-3-phosphate dehydrogenase (GPD), lactate dehydrogenases A and B (LDH-A and LDH-B), malic enzyme 2 (ME-2), isocitrate dehydrogenase 1 (ICD-1), phosphogluconate dehydrogenase (PGD), glutamate-oxaloacetate transaminase 1 (GOT-1) phosphoglucomutase 2 (PGM-2), leucine aminopeptidase (LAP), glucosephosphate isomerase (GPI), and esterase 2 (ES-2, from kidney). Four of the isozymes show patterns that cannot be interpreted by a simple genetic model: esterases 1 and 4 (ES-1, ES-4, from hemolysate), esterase 3 (ES-3, from plasma), and protein 1 (PT-1). The following pairs of loci are assorting independently: LAP and PGD, LAP and PGM-2, GOT-1 and PGD, GOT-1 and GPD, LAP and GPD, GPD and PGD, GPI and PGD. Data from one test cross mating indicate that GPD and PGM-2 are loosely linked with recombination about 30%. Additional data are needed to confirm this relationship.

Complete absence of the third component of complement in man

A 4-yr-old female patient who has recurrent infections with encapsulated bacteria and gramnegative organisms was found to have a complete absence of total hemolytic complement and C3. Total hemolytic complement was reconstituted by the addition of functionally pure C3. With the exception of a moderately reduced homolytic C4, all other C components, measured homolytically and by radial immunodiffusion, were present in normal amounts. By Ouchterlong analysis, the patient's serum contained C3b inactivator and properdin but no antigenic C3. Activation of the alternate pathway was examined by purified cobra venom factor (CVF) and inulin. Neither of these substances led to activation of properdin factor B to B. On addition of partially purified Cordis C3, in four out of four instances and with different preparations of Cordis C3, activation of factor B to B occurred in the inulin-serum-C3 mixture. In contrast, activation of factor B to B occurred only once out of four times with CVF-serum-C3 mixtures. Immune adherence was found to be normal in the patient's serum and could be removed by anti-C4 antiserum of hydrazine treatment. A marked opsonic defect was present against Escherichia coli. Serum bactericidal activity against a rough strain of E. coli was also defective. The ability to mobilize an infalmmatory response was examined by Rebuck skin window technique. A delay in neutrophil migration occurred until the 6th h. In vitro lymphocyte transformation and serum immunoglobulins were normal. The proportion of peripheral blood T cells forming spontaneous sheep erythrocyte rosettes and the percentage of B cells forming EAC rosettes by the C3 receptor were normal. The significance of the absence of C3 in our patient is emphasized by the increased number of infections with encapsulated bacteria and the decreased functional biological activities of the C system, important in host defense mechanism(s).

Horseshoe crab lactate dehydrogenases: evidence for dimeric structure

D-Lactate dehydrogenase of Limulus polyphemus occurs in six molecular forms, not in five as does the L-lactate dehydrogenase of vertebrates. The electrophoretic pattern of bands in an apparent genetic variant is incompatible with a model of tetrameric molecular structure, and suggests, rather, that the three more anodally migrating isozymes are dimer molecules, the polypeptide subunits of which are encoded by two genetic loci and are not involved in the formation of the lower triad of isozymes.