A genetic study of intergradation between Mytilus edulis and Mytilus galloprovincialis

A study of geographic variation at 2 diagnostic allozyme loci in the mussels Mytilus edultis and M. galloprovincialis reveals considerable spatial variation, both in allele frequencies and in the extent of intergradation.     

Atmungsphysiologische Untersuchungen anMytilus edulis galloprovincialis

Résumé ChezMytilus, on remarque une baisse sensible de la consommation d'oxygène après l'ablation des ganglions viscéraux, ce qui prouve que ceux-ci jouent un rôle considérable dans la régulation respiratoire.     

The occurrence of filamentous banded elements as components ofMytilus galloprovincialis byssus

Résumé L'examen au microscope électronique de sections ultra-minces de différentes portions du byssus deMytilus galloprovincialis a révélé pour la première fois la présence de structures filamenteuses périodiques (FBE). Leur période a une longueur de 1000 Å en moyenne, elle est symétrique et comporte deux fractions: A et B. Il est possible que ces structures correspondent à une organisation particulière de la protéine collagène.     

Demonstration of vitamin D3 metabolism inmytilus edulis

Summary Radiolabeled vitamin D₃ was converted into several polar metabolites upon incubation with tissue homogenates from the common musselMytilus edulis. Chromatographic analysis indicated that the metabolites have chromatographic mobilities different from those of known standards. The results suggest that vitamin D₃ is metabolized in mussels via pathways that differ from the vertebrate systems.Acknowledgments. The authors thank Dr Pirjo Rantamäki for the mussels and F. Hoffmann-La Roche & Co. for supplying the vitamin D₃ metabolite standards. This work was supported by a grant from the Magnus Ehrnrooth Foundation to T. K.     

Role of genetic variability in neonatal jaundice. A prospective study on full-term,blood group-compatible infants

A series of genetic, developmental and environmental variables have been analyzed in a prospective sample of full-term newborn babies, compatible with their mothers in the major blood group systems, in order to attempt an evaluation of the effect of these variables on serum bilirubin level during the first few days of life. Three genetic factors (PGM₁, ACP₁ and ADA) and three non-genetic variables (rise of bilirubin level during the first day of life, a mother with a history of previous abortion, and use of alcoholic beverages by the mother) have a significant predictive value for the separation of newborns with clinically relevant jaundice from other infants.     

A simple test using restricted PCR-amplified mitochondrial DNA to study the genetic structure ofApis mellifera L

The COI-COII intergenic region ofApis mellifera mitochondrial DNA contains an important length polymorphism based on a variable number of copies of a 192–196 bp sequence (Q) and the completer or partial deletion of 67 pb sequence (Po). This length variability has been combined with a restriction site polymorphism to produce a rapid and simple test for the characterization of mtDNA haplotypes. This test included the amplification by the polymerase chain reaction of the COI-COII region followed by aDraI restriction of the amplified fragment. In a survey of 302 colonies belonging to 12 subspecies, 21 different haplotypes have been found which have been unambiguously allocated to one of the 3 mtDNA lineages of the species. Although all colonies of lineage C exhibit the same pattern (C1), each one of lineages A and M presents up to 10 different haplotypes, opening the way to studies on the genetic structure and the evolution of a large fraction of the species. This test also differentiates southern Spanish and South African colonies, which can be of great interest for the Africanized bee problem.     

A short-term culture method for chromosome preparation from somatic tissues of adult mussel (Mytilus edulis)

In order to improve the efficiency of mussel chromosome preparation, a tissue culture procedure has been developed. Mantle and foot explants were grown in tubes in media composed of Eagle's Basal Medium supplemented either with salts or seawater, enriched with egg yolk, adjusted to pH 7.50, and containing penicillin and streptomycin. After 4 days of incubation at 18°C, antibiotics were renewed and after 6–7 days, cultures were ready for harvesting and preparation of microscopical slides. The cultures were a source of actively dividing cells and consistent metaphase spreads were obtained. Evidence from BrdU incorporation suggested that cells could undergo several rounds of replication. The chromsome spreads were good enough for karyotyping and to successfully silver stain the nucleolar organizer regions.     

Role of genetic variability in neonatal jaundice. A prospective study on full-term, blood group-compatible infants.

A series of genetic, developmental and environmental variables have been analyzed in a prospective sample of full-term newborn babies, compatible with their mothers in the major blood group systems, in order to attempt an evaluation of the effect of these variables on serum bilirubin level during the first few days of life. Three genetic factors (PGM1, ACP1 and ADA) and three non-genetic variables (rise of bilirubin level during the first day of life, a mother with a history of previous abortion, and use of alcoholic beverages by the mother) have a significant predictive value for the separation of newborns with clinically relevant jaundice from other infants.     

A spatial depiction for the systematically degenerate genetic code

Zusammenfassung Auf Grund von Literaturangaben und durch Deduktion haben wir ein dreidimensionales Schema (oder Modell) des systematisch degenerierten genetischen Codes entworfen, aus dem man in einfacher Weise ablesen kann, welche Aminosäuresubstitutionen aus der Veränderung einer Base folgen.     

An analysis of allozyme,mitochondrial DNA and morphological variation in mussel (Mytilus galloprovincialis) populations from Greece

Three populations ofM. galloprovincialis from northern Greece were investigated using isozyme analysis, discriminant analysis of morphological characteristics and analysis of restriction fragments of mtDNA. For all three types of analysis significant intra- and interpopulation differentiation was found. This differentiation is very noticeable at the mtDNA genotype frequencies. Furthermore, the restriction patterns of mtDNA were different from those reported for Atlantic populations of this species.     

Transgenic and mutant animal models to study mechanism of protection of red cell genetic defects against malaria

Malaria, caused by members of the genusPlasmodia, is still the most prevalent parasitic disease in the world. In an attempt to understand genetic factors conferring resistance to malaria, mouse models of thalassemia, sickle trait, and ankyrin and spectrin deficiency were studied during infection with species of malaria infectious to rodents. Although growth ofP. falciparum is not inhibited in thalassemic erythrocytes in culture, mice carrying a -thalassemia mutation were protected fromPlasmodium chabaudi adami, supporting epidemiologic findings. Transgenic mice expressing ^s hemoglobin were also significantly protected from two species of rodent malaria. Importantly, a significant role for the spleen in protection in the ^s transgenic mice was found. Finally, mice deficient in spectrin and ankyrin were studied with respect to their ability to support the growth of malaria. It was found that spectrin deficient mice were almost completely refractory toP. chabaudi adami andP. berghei. These models will allow further study of host factors in resistance to malaria.     

A study of transamination system inFusarium

Zusammenfassung AusFusarium lycopersici wurde ein Enzympräparat gewonnen, welches Glutaminsäure durch Transaminierung aus -Ketoglutarsäure bildete. Von den geprüften 20 Aminosäuren dienten die folgenden als Donatoren der Aminogruppe: Tyrosin, Ornithin, Alanin, Methionin, Leucin, Isoleucin, Prolin, Phenylalanin, Tryptophan, Valin und Asparaginsäure. Das Transaminasesystem scheint nicht an Strukturen des Cytoplasmas gebunden zu sein. Die Resultate stimmen im Prinzip mit jenen überein, welche beiNeurospora und bei Hefen gefunden wurden.     

A possible genetic component of obesity in childhood. Observations on acid phosphatase polymorphism

Phenotypes of acid phosphatase with low enzymatic activity (ACP1 A and BA) are correlated with the highest degree of body mass increase observed in a sample of obese children. Since acid phosphatase probably functions as a flavin-mononucleotide phosphatase, differential modulation of flavo-enzyme activity and energy metabolism due to acid phosphatase genetic variability may explain the observed association.     

A hyperpolarizing factor is synthetized in a cell at activation of the genetic apparatus

Summary A factor, hyperpolarizing the plasmic membrane, is synthetized within a cell at activation of its genetic apparatus.     

A possible genetic component of obesity in childhood. Observations on acid phosphatase polymorphism

Summary Phenotypes of acid phosphatase with low enzymatic activity (ACP₁ A and BA) are correlated with the highest degree of body mass increase observed in a sample of obese children. Since acid phosphatase probably functions as a flavin-mononucleotide phosphatase, differential modulation of flavo-enzyme activity and energy metabolism due to acid phosphatase genetic variability may explain the observed association.