Hybridation en laboratoire deMus musculus L. etMus spretus Lataste

Summary 2 species of miceMus musculus brevirostris andMus spretus are sympatric in Southern France and reproductively isolated. However, under laboratory conditions, they breed and give fully viable F1 hybrids. This indicates that premating isolating mechanisms probably occur in nature and have yet to be investigated. Moreover, it now enables us to introduce new genetical markers in laboratory strains.

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Remerciements. Cette étude a été menée à bien avec l'assistance technique de J. Catalan. Nous remercions également N. Pasteur, J. Britton-Davidian ainsi que tous les membres du laboratoire pour leurs commentaires avisés dans la discussion des résultats. Ce travail est supporté financièrement par l'Université de Montpellier II, l'EPHE et le C.N.R.S. (ERA-261 et ATP-souris).     

Genetic analysis of interspecific crosses Mus musculus L. x Mus spretus Lataste: linkage of Adh-1 with Amy-1 on chromosome 3 and Es-14 with Mod-1 on chromosome 9]

192 offsprings from interspecific back-crosses (male M. spretus x female BALB/c) F1 x male BALB/c or (male M. spretus x female C57BL6) F1 x male C57BL6 were analysed at thirteen structural loci. Linkage of ES-14 with Mod-1 on chromosome 9 and that of Adh-1 with Amy-1 on chromosome 3 are shown. The following order centromere/Car-2/Amy-1 is tentatively proposed for these loci on chromosome 3.     

Lactate dehydrogenase isozymes of mouse epidermis.

Five isozymes of LDH are demonstrable in the epidermis of the ear pinnae, hind feet, trunk dorsa, and tails of adult C57BL, C57HR, and C3HB mice by polyacrylamide gel electrophoresis. LDH-5 activity predominates in electropherograms. The ratio of LDH-1 to LDH-K is greater in the epidermis of ear pinna and trunk dorsum than in that of tail and hind foot. The region-specific patterns of epidermal LDH isozymes are not correlated with melanin pigmentation or "hairiness' of the skin.     

Robertsonian chromosomal polymorphism in the mouse (M. musculus domesticus)

Zusammenfassung Hausmäuse (M. m. domesticus) aus dem Bergell/GR zeigen einen intraspezifischen Chromosomenpolymorphismus vomRobertson'schen Typ mit wenigstens zwei verschiedenen metazentrischen Chromosomen. Für eines dieser beiden Chromosomen konnte gezeigt werden, dass es von den sieben bei der Tabakmaus (M. poschiavinus) vorhandenen metazentrischen Chromosomen unabhängig ist. Ein für dieses Chromosom (T8Bnr) homozygoter Stamm auf dem Hintergrund der Laboratoriumsmaus wird für experimentelle Verwendung herausgezüchtet.

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Work supported by Landesamt für Forschung, Nordrehein-Westfalen.     

Lactate dehydrogenase isozymes in xiphophorin fish melanoma conditioned by the locusSd.

Zusammenfassung Elektrophoretische Untersuchungen an benignen und malignen Rückenflossenmelanomen sowie an normalen Rückenflossen lebendgebärender Zahnkarpfen zeigen, dass in den Geweben in erster Linie die für gut mit Sauerstoff versorgtes Gewebe typische Herz-LDH (B₄-Isoenzym) vorkommt. Die für schlecht mit Sauerstoff versorgtes Gewebe typische Muskel-LDH (A₄-Isoenzym) wird nur in manchen der untersuchten Gewebe gefunden, und ist auch dort nur in sehr geringer Menge vorhanden. Die Melanome scheinen also im Gegensatz zu vielen anderen Neoplasmen anderer Systeme aeroben Stoffwechsel durchzuführen.

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Supported by Deutsche Forschungsgemeinschaft through Sonderforschungsbereich 103, Zellenergetik und Zelldifferenzierung (Marburg).

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Richard Merton—Guest Professor through Deutsche Forschungsgemeinschaft.     

Lactate dehydrogenase and glutamate dehydrogenase activities in the circumventricular organs of rat brain following neonatal monosodium glutamate

Glutamate (glu) an excitatory neurotransmitter amino acid, is present in high concentrations in the mammalian central nervous system and is the most abundant amino acid in our daily diet. In the present study the activities of lactate dehydrogenase (LDH) and glutamate dehydrogenase (GDH) were evaluated in the circumventricular organs (CVO) of the brain in 25-day-old rats following MSG administration at a dose of 4 mg/g b.wt during the first ten days of life. The results show the LDH activity increased to 265% of that in the control (p<0.001), whereas GDH activity was significantly decreased (p<0.05), The great elevation in LDH, a cytoplasmic marker enzyme, is apparently due to cytoskeletal changes brought about as a consequence of glu toxicity, whereas lowered GDH activity indicates altered glu homostasis in the blood-brain-barrier deficient areas following neonatal exposure to glu.     

Lactate dehydrogenase specificity and subunit assembly in neural tissues of the teleostPhallichthys amates

Summary The tissue specificity of lactate dehydrogenase (EC 1.1.1.27) in brain and eye of the teleostPhallichthys amates was examined by acrylamide gel electrophoresis. It is suggested that subunit association is a function of gene product accessibility superimposed upon genetic restriction of assembly.     

Glucose-6-phosphate dehydrogenase activity in the ovaries ofScomber scomber L.

Résumé L'activité de la glucose-6-phosphate déshydrogénase a été étudiée histochimiquement dans les ovaires du maquereau. Les cellules thécales et folliculaires du follicule montrent une activité marquée de la glucose-6-phosphate déshydrogénase connue comme le plus important système engendrant la triphosphopyridine-nucléotide réduite, nécessaire pour la synthèse des hormones stéroides.     

Lactate dehydrogenase activity in cell subpopulations of 7,12-dimethylbenz(a)anthracene-induced mammary tumors

Heterogeneity of cells in a solid tumor prevents direct assessment of enzyme activity of cell subpopulations by conventional homogenization techniques. Lactate dehydrogenase (LDH) activity before and after ovariectomy and following estrogen supplementation in density-defined cell subpopulations from DMBA-induced mammary tumors was determined. Different levels of LDH activity were found in different cell subpopulations. After ovariectomy the level of LDH activity declined. Restoration of the circulatory estrogen level resulted in increased enzyme activity. The highest level of LDH was found in a band which consisted mainly of poorly differentiated cells. This cell subpopulation also tended to be more responsive to endocrine manipulation.     

On the chromosomic polymorphism ofRattus rattus L. a study on West-European populations

Riassunto Nell'ambito del problema del polimorfismo cromosomico diRattus rattus è stato studiato il cariotipo di varie popolazioni europee (Italia, Svizzera, Francia ed Inghilterra) riferibili alle sottospeciefrugivorus, rattus edalexandrinus. Il numero diploide osservato è sempre stato2n=38 e non è emersa nessuna differenza morfologica tra i cariogrammi delle varie popolazioni.

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This research was supported by the Gruppo di Studio per le popolazioni insulari del C.N.R..     

Hormonal induction of glutamate dehydrogenase in rat liver.

Glutamate dehydrogenase rapidly increases in microsomes and appears in the cytoplasm after administration of cortisone, cAMP, hydrocortisone-acetate. Prolonged administration of ACTH maintains high level of enzyme in the mitochondria and microsomes. Hydrocortisone-acetate, insulin and cortisone decrease drastically enzyme in mitochondria.     

Neoplasms inLumbricus terrestris L.

Zusammenfassung Cancerogene Chemikalien oder Röntgenstrahlen verursachten am Regenwurm (Lumbricus terrestris) verschiedene neoplastisch aussehende Beschädigungen.     

Regional distribution of lactate dehydrogenase isoenzymes in adult rat brain.

The highest lactate dehydrogenase (LDH) activity was found in thalamus, statistically significantly less in cerebral and cerebellar cortex and the lowest in pons. LDH1 and LDH4+5 represented 58% and 23% of the total activity in cerebral cortex, 54% and 20% in thalamus, 42% and 4% in cerebellar cortex and 55% and 7% in pons, respectively.     

Succinic dehydrogenase activity during starvation of a terrestrial pulmonateAriophanta sp.

Zusammenfassung Nachweis, dass die Dehydrogenase-Aktivität im Hepatopankreas, Fuss und Schlundring bei der Lugenschneckeariophanta sp. eine ausgesprochene Enzymanpassung an die veränderten Stoffwechselbedingungen während langfristiger Hungerperioden zeigt und damit auf einen Überlebensmechanismus hinweist.