A further study of LDH isozymes in theRana esculenta complex

Summary Electrophoretic analyses of LDH isozymes in the 3 types of European green frogs by using the buffer system of Williams and Reisfeld demonstrated the occurrence of 4 allelic genes coding for the B subunits. Based on the distribution of these alleles and results from dissociation and recombination of the subunits, the hybrid nature of Rana esculenta is confirmed.This study was supported in part by the Swiss National Science Foundation and the Georges-und-Antoine-Claraz-Schenkung.     

Genetic control of LDH isozymes in the Rana esculenta complex.

Studies of LDH isozymes in the European green frogs showed that the synthesis of the B subunits is controlled by 3 alleles at a single genetic locus. The genetic evidence supports the hypothesis that Rana esculenta is the hybrid of R. lessonae X R. ridibunda.     

Experimental gynogenesis provides evidence of hybridogenetic reproduction in theRana esculenta complex

Summary The gynogenetic offspring of the hybrid frogRana esculenta (R. ridibunda x R. lessonae) are exclusively of theridibunda type. This is due to the premeiotic exclusion of thelessonae genome from the hybrid's germ cells.Acknowledgments. Prof. M. Fischberg, Genève, and Prof. P. Vogel, Lausanne, provided laboratory facilities. This research was supported by the Swiss National Science Foundation, grants 3.221-0.73 and 3.644-0.75.     

Biochemical variation in theRana esculenta complex: A new hybrid form related toRana perezi andRana ridibunda

Summary Investigations of the green frogs from western Europe for electrophoretic variations at 4 enzyme loci demonstrated a new form which must be considered as a hybrid betweenRana ridibunda andR. perezi. Biochemical evidence supports the hypothesis that its reproduction is hybridogenetic, as it is forR. esculenta.     

Rana esculenta complex: An experimental analysis of lethality and hybridogenesis

Summary Experiments designed to analyze the lethality and hybridogenesis in the European green frog complex have yielded the following results: 1. As a rule the inter-se cross ofRana esculenta is lethal, but several crosses have produced fully viable progeny. The frequency of such break-through crosses appears to be related to parental population structure. 2. Parabiotic joining of lethal to viable embryos indicates that manifestation of the lethal effect is autonomous. There is, however, a 16–18% increase in the life span of the lethal partner. 3. Studies of LDH isozyme patterns revealed that thelessonae-specific alleles coding for the B^a and B^c subunits can be passed to the F₁ progeny from a parental female or male of theesculenta phenotype. This demonstrates that there is no total elimination of thelessonae genome in theesculenta germ cells. 4. Immunologically, offspring from the inter-se cross ofR. esculenta show a closer relationship to theridibunda than to theesculenta phenotype. Variations of antigenic protein patterns suggest the possibility of chromosomal recombination betweenlessonae andridibunda in theesculenta hybrid. These results are confirmed by two-dimensional electrophoretic analysis of proteins in the oocytes of the three frog phenotypes.This work was supported by grants from the Swiss National Science Foundation and the Georges and Antoine Claraz Schenkung.     

Experimental gynogenesis provides evidence of hybridogenetic reproduction in the Rana esculenta complex.

The gynogenetic offspring of the hybrid frog Rana esculenta (R. ridibunda X R. lessonae) are exclusively of the ridibunda type. This is due to the premeiotic exclusion of the lessonae genome from the hybrid's germ cells.     

The control of the frog (Rana esculenta) thumb pad

Summary Extirpation of the pars distalis of the pituitary or castration in any period of the year cause thumb pad regression. Thumb pad development is regulated by an interaction of both temperature and androgenic hormones.Work done under the C.N.R.-finalized project Biologia della Riproduzione.     

A logical approach to the isolation of lactate dehydrogenase isozyme X from human tests: A general rationale for the isolation of homotetrameric LDH isozymes

Summary Immunoadsorbent and oxamate-Sepharose chromatography were used to isolate electrophoretically homogeneous LDH-X from human testes with a final specific activity of 125 IU/mg and good yields: other applications of this approach are discussed.This work was supported by the Rockefeller Foundation.     

Genetic control of dormancy in the potato cyst-nematode

Summary Matings of early-hatched parents of the potato cyst-nematode:H. rostochiensis, gave F₁ which hatched early-late-hatched parents gave progeny which showed dormancy, the extent fo which was in most instances determined by the parents' time of hatching. It is suggested that dormancy is genetically controlled.     

Genetic control of rye endosperm proteins

Résumé En comparant les diagrammes d'électrophorèse en gels d'amidon de gliadine obtenus à partir d'un blé hexaploïde, d'un seigle diploïde et de blé + seigle amphiploïdes avec les lignes d'additionnement des chromosomes blé-seigle on constata qu'un chromosome de seigle contrôle toutes les gliadines du seigle.     

Biochemical variation in the Rana esculenta complex: a new hybrid form related to Rana perezi and Rana ridibunda.

Investigations of the green frogs from western Europe for electrophoretic variations at 4 enzyme loci demonstrated a new form which must be considered as a hybrid between Rana ridibunda and R. perezi. Biochemical evidence supports the hypothesis that its reproduction is hybridogenetic, as it is for R. esculenta.     

Ovarian LDH activity in gonadotropin-treated immature rats

Summary Lactate dehydrogenase (LDH) activity was studied in the ovaries of immature rats treated with pregnant mare serum gonadotropin (PMS). LDH activity increased sharply at 36 h after PMS injection in the ovarian tissue as well as in the blood. It was suggested that the increase of LDH activity in the ovary may be related to its increasing ability to secret estrogen.