Jean-Paul Thirion

Biochemical and genetic characterization of respiration-deficient mutants of Chinese hamster cells with a Gal- phenotype.

Four Chinese hamster somatic cell mutants A13G9, 34A13G32, 2A13G14, and V6IG15 with a Gal− phenotype have the following characteristics: (1) a low respiration rate; (2) a reduced Krebs cycle activity; (3) a low level of stimulation of oxygen consumption of mutant mitochondria by malate; (4) an absolute dependence on an ample supply of glucose to sustain a high rate of glycolysis; (5) a defect in the electron transport chain from NADH to coenzyme Q; and (6) no appreciable activity of rotenone-sensitive NADH oxidase in mutant mitochondria. These four mutants and another mutant, P12GX1, were analyzed by complementation analysis using seven other respiratory mutants of Dr. Scheffler which define seven complementation groups (I–VII). P12GX1 fails to complement mutant CCL16-B9 (group IV). A13G9 and 34A13G32 do not complement each other. Mutants V6IG15, A13G9, and 34A13G32 define two new groups of complementation (VIII and IX), while 2A13G14 does not complement mutants of groups II and VI.

Monoclonal antibodies against metallothioneins and metalloproteins.

Monoclonal antibodies against rabbit metallothioneins (MT) were prepared by in vitro immunization of mouse lymphocytes with a mixture of the two forms of metallothionein MT1 and MT2. Six IgM antibodies (TN1,3,4,5,6,7) which bind to metallothionein were characterized. Antibody TN3 is specific for rabbit MT1 and does not react with any other MTs tested. TN5 is specific for both rabbit MT1 and MT2. TN7 is specific for rabbit MT2 but not MT1 and cross-reacts also with Chinese hamster, mouse and rat metallothioneins. The antibodies TN1, TN4 and TN6 bind not only to rabbit MT1 and MT2 but also to other metal binding proteins like alcohol dehydrogenase and carbonic anhydrase.

Linkage disequilibrium and founder effect analysis of the NF1 gene in French Canadians from the Quebec population.

We genotyped 19 neurofibromatosis type 1 (NF1) families from French Canadians of the Quebec population with four intragenic microsatellites (IVS26-2.3, IVS27AC28.4, IVS27AC33.1, and IVS38GT53.0). Linkage analysis of the four microsatellite markers among the 19 NF1 families indicates that the four microsatellites are strongly linked with NF1 disease (LOD = 2.76-3.64). The four markers are associated (P = 0-0.077) except marker pair IVS26-2.3/IVS27AC33.1 (P = 0.18 or 0.17). However, perhaps due to the high mutation rate of the NF1 gene, no founder effect for NF1 was detected in the Quebec French Canadians.