The sequence and organization of the core histone H3 and H4 genes in the early branching amitochondriate protistTrichomonas vaginalis

Among the unicellular protists, several of which are parasitic, some of the most divergent eukaryotic species are found. The evolutionary distances between protists are so large that even slowly evolving proteins like histones are strongly divergent. In this study we isolated cDNA and genomic histone H3 and H4 clones fromTrichomonas vaginalis. Two histone H3 and three histone H4 genes were detected on three genomic clones with one complete H3 and two complete H4 sequences. H3 and H4 genes were divergently transcribed with very short intergenic regions of only 194 bp, which containedT. vaginalis-specific as well as histone-specific putative promoter elements. Southern blot analysis showed that there may be several more histone gene pairs. The two complete histone H4 genes were different on the nucleotide level but encoded the same amino acid sequence. Comparison of the amino acid sequences of theT. vaginalis H3 and H4 histones with sequences from animals, fungi, and plants as well as other protists revealed a significant divergence not only from the sequences in multicellular organisms but especially from the sequences in other protists likeEntamoeba histolytica, Trypanosoma cruzi, andLeishmania infantum.     

Immunolocalization of Na,K-ATPase in blowfly photoreceptor cells

The Na,K-ATPase (sodium pump) plays a central role in the physiology of arthropod photoreceptors as it re-establishes gradients for Na⁺ and K⁺ after light stimulation. We have mapped the distribution of the Na,K-ATPase in the photoreceptors of the blowfly (Calliphora erythrocephala) by immunofluorescent and immunogold cytochemistry, and demonstrate that the distribution pattern is more complex than previously presumed. High levels of sodium pumps have been detected consistently in all photoreceptors R1-8 on the nonreceptive surface, but no sodium pumps are found on the microvillar rhabdomere. Within the nonreceptive surface of the cells R1-6, however, the sodium pumps are confined to sites juxtaposed to neighboring photoreceptor or glial cells; no sodium pumps have been detected on the parts of the nonreceptive surface exposed to the intra-ommatidial space. In R7 and R8, the sodium pumps are found over the entire nonreceptive surface. The cytoskeletal protein spectrin colocalizes with the sodium pumps suggesting that linkage of the pump molecules to the spectrin-based submembrane cytoskeleton contributes to the maintenance of the complex pattern of pump distribution.     

Analysis of DNA polymerase activity in Petunia protoplasts treated with clastogenic agents

Clastogenic agents, i.e. agents that can induce chromosome or DNA breakage, have been shown to enhance the rale of direct gene transfer to protoplasts. The effect was analysed at the enzymatic level using protoplast homogenates as well as intact protoplasts. For that purpose existing procedures were modified to enable measurement of DNA polymerase in vivo. In the system used, external DNA was able to enter the cells without the addition of membrane-permeabilizing compounds. When comparing total DNA polymerase activity of protoplasts irradiated with X-rays or UV-light with that of untreated cells we did not observe significant differences. Incubation of protoplasts with high doses of bleomycin affected total DNA polymerase activity negatively. but dideoxythymidine triphosphate-sensitive activity was not influenced. We conclude that the DNA strand-breaks induced by low doses of X-rays. UV-light or bleomycin do not increase the total or the repair-DNA polymerase activity and. therefore. that the increase in the transformation rates after DNA strand-breaking is not preceded by enhanced DNA polymerase activity.     

Presence and role of jasmonate in apple embryos

(-)Jasmonic acid (JA) was identified in extracts front embryos of apple (Mulus domestica) by combined gas chromatography-mass spectromelry. Quantification of JA in embryos isolated from seeds at different perexts of stratification by gas chromalography combined with mass spectrometry/selective ion monitoring indicated a sharp peak at day 30. At the same time the maximal ratio of conjugated to free JA was found by enzyme-linked imrnunosorbent assay (ELISA). Germination of embryo.s was stimulated by added JA and inhibited by salieylhydroxamic acid (SHAM, an inhibitor of lipoKygenase). Both stimulation and inhibition disappeared in embryos stratified for more than 30 days. Methyl jasmonate was more effective in stimulation of embryo germination than free JA. while JA-isoleucine inhibited germination. The possible mechanism responsible for changes in JA level as wel! as the role of JA and its conjugates in removal of dormancy in apple seeds are discussed.     

Molecular and genetic characterisation of German families with paramyotonia congenita and demonstration of founder effect in the Ravensberg families

Eighteen German families with a history of paramyotonia congenita (PC) were characterised by genetic und mutational analysis at the SCN4A locus, which encodes the -subunit of the adult skeletal muscle sodium channel. We concentrated our analysis primarily on these families to test the hypothesis that a predominance of one common mutation occurs in all German PC families and that this mutation arose in a common ancestor originating in the North-West of the country. The present eighteen PC families exhibit two different mutations (R1448C and R1448H) on various SCN4A dinucleotide repeat haplotypes and therefore the majority of the mutations probably occurred independently. However, the R1448H mutation is extremely frequent in the North-West of Germany (Ravensberger Land) on a specific SCN4A microsatellite haplotype, indicating a founder effect within this subpopulation. Our results suggest that the R1448C/R1448H mutations are by far the most common to be associated with the PC phenotype in the German population.This paper is dedicated to Professor Dr. Dr. Peter Emil Becker on the occasion of this 85th birthday     

Polymorphisms of the apolipoprotein and angiotensin converting enzyme genes in young North Karelian patients with coronary heart disease

The genes encoding apolipoproteins (apos) A-I, B, C-III and E as well as that encoding the angiotensin converting enyzme (ACE) have been proposed as candidate genes for coronary heart disease (CHD). We determined the common polymorphisms of the apo genes, previously found to influence serum lipid levels at the population level, and the insertion/deletion polymorphism of the ACE gene, recently reported to reflect the risk of myocardial infarction, in 82 very young (mean, 41 years) North Karelian Finns with symptomatic CHD and 50 controls of similar age. Patients with familial hypercholesterolemia had been excluded from this material. None of the polymorphisms examined, including the apo A-I promoter MspI, apo C-III SstI and apo B XbaI restriction fragment polymorphisms, a common variation of apo E (2, 3 and 4 alleles) and an ACE insertion/deletion (I/D) polymorphism, was significantly associated with the risk of premature CHD. Patients with CHD had a higher mean serum LDL cholesterol/HDL cholesterol ratio than controls (3.15±1.30 vs 2.72±0.98, P < 0.05), but no significant associations between the common apo gene polymorphisms and serum lipid levels were disclosed in either group. It is possible that other genetic loci than those proposed to be associated with accelerated atherosclerosis may be more important as risk factors of symptomatic CHD at the age of 40 years.     

Growth of legionella and other heterotrophic bacteria in a circulating cooling water system exposed to ultraviolet irradiation

The effect of ultraviolet irradiation on the growth and occurrence of legionella and other heterotrophic bacteria in a circulating cooling water system was studied. Water of the reservoir was circulated once in 28 h through a side-stream open channel u.v. radiator consisting of two lamps. Viable counts of legionellas and heterotrophic bacteria in water immediately after the u.v. treatment were 0—12 and 0·7—1·2% of those in the reservoir, respectively. U.v. irradiation increased the concentration of easily assimilable organic carbon. In the u.v. irradiated water samples incubated in the laboratory the viable counts of heterotrophic bacteria reached the counts in reservoir water within 5 d. The increase in viable counts was mainly due to reactivation of bacterialcells damaged by u.v. light, not because of bacterial multiplication. Despite u.v. irradiation the bacterial numbers in the reservoir water, including legionellas, did not decrease during the experimental period of 33 d. The main growth of bacteria in the reservoir occurred in biofilm and sediment, which were never exposed to u.v. irradiation.     

Polymorphism of legumin subunits from field bean (Vicia faba L. var. minor) and its relation to the corresponding multigene family

Legumin, which amounts to approximately 55% of the seed protein in field beans (Vicia faba L. var. minor), is a representative of the 12S storage globulin family. The 12S storage globulins are hexameric holoprotein molecules composed of different types of polymorphic subunits encoded by a multigene family. Type-A legumin subunits contain methionine whereas type-B are methionine-free subunits. Sequencing of two different type A-specific cDNAs, as well as an FPLC/HPLC-based improvement of subunit fractionation and peptide mapping with subsequent partial amino-acid sequencing, permit the assignment of some of the polymorphic legumin subunits to members of the multigene family. Two different type A subunits (A1 and A2) correspond to the two different cDNA clones pVfLa129 (A2) and 165 (A1), but microheterogeneity in the amino-acid sequences indicates that polymorphic variants of both representatives of this type may exist. Two groups of published type B-specific gene sequences (LeB7, and LeB2, LeB4, LeB6, respectively) are represented by two polymorphic subunit fractions (B3I, B3II, and B4I, B4II). A seventh clone, LeB3, encodes one of the large legumin subunits that is only a minor component of the legumin seed protein complex.     

Comparison of fatty acids of marine fungi using multivariate statistical analysis

Summary Ten obligate marine fungi have as their principal fatty acids 160, 180, 181n9 and 182n6. The fatty acids ranged from 14 to 22 carbons, completely dominated by those with even numbers of carbons. The amount of unsaturated fatty acids varied between 35% and 80%. Each isolate contained small amounts of the acids 183n3 and 204n6. Branched, hydroxy- or cyclic fatty acids were not detected. Multivariate statistical, i.e. principal component analysis, showed that all ten strains could be distinguished on the basis of their fatty acid composition. These results indicate that the marine fungi do not have an unusual fatty acid composition and suggest that chemometric, multivariate analysis might be employed to confirm taxonomic relationships among these organisms.