Mitochondrial DNA variations and nuclear RFLPs reflect different genetic similarities among 23 Arabidopsis thaliana ecotypes

The mitochondrial genome of 23 Arabidopsis thaliana ecotypes was analysed by Southern hybridization in total cellular DNA. Firstly, the extent of divergence between the mitochondrial genomes in closely related lines of one plant species and secondly, the use of mitochondrial versus nuclear RFLPs to determine evolutionary relationships between Arabidopsis ecotype isolates was investigated. Highly divergent stoichiometries of alternative mitochondrial genome arrangements characterize individual ecotypes including the complete loss of a 5 kb region from ecotype Landsberg without apparent effect on plant viability. The genetic similarities between ecotypes suggested by mitochondrial genome arrangements differ from those deduced from 18 nuclear RFLP loci (CAPS markers). Similarity of nuclear RFLP patterns among the 23 Arabidopsis ecotypes neitehr correlates with their geographic origin nor with the observed mitochondrial genome arrangements. A promiscuous mitochondrial sequence insertion previously identified in ecotype Columbia is also found in the nuclear genomes of ecotypes Eifel, Enkheim and Hilversum. Two ecotypes (Eifel and Tabor) displaying identical RFLP patterns at all 18 nuclear loci show differences in both this sequence transfer and a mitochondrial DNA recombination event.     

Phosphoinositide-generated messengers in cardiac signal transduction

A multitude of agonists like e.g. endothelin-I, angiotensin-II, serotonin, thrombin, histamine and vasopressin as well as ₁-adrenergic and muscarinic stimulation lead to stimulation of the phosphoinositide cycle in the heart. Besides this seven membrane spanning-domain receptor-coupled stimulation of the key enzyme of the phosphoinositide cycle, phospholipase C-, another class of hormones, growth factors, also couple to the phosphoinositide cycle, now through receptors with intrinsic tyrosine kinase activity that can phosphorylate and stimulate the phospholipase C- isozyme. In this review we summarize the multitude of receptor (sub)types, G-protein-subunit- and phospholipase C-isozymes that are present in the heart. Furthermore, generation of second messengers and cellular responses are described together with the (patho)physiological implications for the heart of phosphoinositide cycle activation and second messenger accumulation.     

Analysis of transgene integration sites in transgenic pigs by fluorescence in situ hybridization

The production of pigs transgenic for human decay accelerating factor (hDAF) as potential donors for clinical organ xenotransplantation was reported several years ago. For this purpose it is required that high levels of hDAF are expressed at relevant sites in transplantable organs. Currently, homozygous lines have been produced as well as lines from crosses between heterozygous animals from different founder lines, termed jigsaw pigs. The purpose of the jigsaw crosses is to combine the desirable hDAF protein expression patterns found in different founder lines. Initial selection of the jigsaw pigs is based on the inheritance of the hDAF integration sites from both lines. Litters with potential homozygous transgenics and jigsaw transgenics were analysed by fluorescence in situ hybridization (FISH) and slot blot analysis. Results show that both slot blot analysis and FISH are suitable to distinguish between pigs that are heterozygous and homozygous for hDAF. However, FISH has the advantage of producing results more rapidly. For the identification of jigsaw pigs FISH analysis was required since slot blot analysis lacked the required accuracy. On basis of these results, FISH analysis was made part of the routine screening programme for hDAF transgenic pigs     

Uneinheitlicher Phänotyp bei Partialtrisomie 4q

Zusammenfassung Es wird über die klinischen und cytogenetischen Befunde bei 3 nichtverwandten Patienten mit Partialtrisomie 4q berichtet. In 2 Fällen ist die Chromosomen-aberration durch eine balancierte elterliche Translokation entstanden (t(3p+;4q-) und t(4q-;18q+)) während im 3. Fall eine spontane invertierte Insertion von 4q22q34 in 4q34 angenommen wird.Ein Vergleich der Symptomatik dieser Patienten mit 7 Fällen aus der Literatur läßt keinen einheitlichen Phänotyp erkennen.

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Phenotypic variation in partial trisomy 4q

Summary The clinical and cytogenetic data of 3 non-related patients who have a partial trisomy 4q in common are reported. The chromosome aberration originated from a parental balanced translocation in 2 cases (t(3p+;4-) and t(4q-;18q+)); in the 3rd case an inverted insertion of 4q22q34 into 4q34 occured spontaneously.A comparison of the symptoms exhibited by these probands and 7 cases from the literature gives no indication of an uniform phaenotype of this aberration.

     

Mercuric reductase activity in the adaptation to cationic mercury, phenyl mercuric acetate and multiple antibiotics of a gram-negative population isolated from an aerobic fixed-bed reactor.

Eighty-eight strains, isolated from an aerobic fixed-bed reactor and identified to the genus level, were examined for resistance to 21 antibiotics, cationic mercury and phenylmercuric acetate. All except three were able to grow on Mueller-Hinton agar plates containing 8 micrograms/ml mercuric chloride, but only 42 exhibited a mercuric reductase and an organomercurial lyase activity. Furthermore, 82 of them were multiply-antibiotic resistant, whereas no positive correlation between this property and cationic mercury volatilization capacity was found. It was concluded that this bacterial community-adapted response to these selective agents, which has been most often shown to be mediated by R plasmids, was the result of two independent phenomena. Moreover, the high percentage of multiple antibiotic and mercury resistance found in this population suggested that simultaneous selections occurred on filters of bacteria which exhibited mucoid colonies and tolerance to these two categories of stress agents.     

Mercuric reductase activity in the adaptation to cationic mercury, phenyl mercuric acetate and multiple antibiotics of a Gram-negative population isolated from an aerobic fixed-bed reactor

C. HENRIETTE, E. PETITDEMANGE, G. RAVAL AND R. GAY. 1991. Eighty-eight strains, isolated from an aerobic fixed-bed reactor and identified to the genus level, were examined for resistance to 21 antibiotics, cationic mercury and phenylmercuric acetate. All except three were able to grow on Mueller-Hinton agar plates containing 8 μg/ml mercuric chloride, but only 42 exhibited a mercuric reductase and an organomercurial lyase activity. Furthermore, 82 of them were multiply-antibiotic resistant, whereas no positive correlation between this property and cationic mercury volatilization capacity was found. It was concluded that this bacterial community-adapted response to these selective agents, which has been most often shown to be mediated by R plasmids, was the result of two independent phenomena. Moreover, the high percentage of multiple antibiotic and mercury resistance found in this population suggested that simultaneous selections occurred on filters of bacteria which exhibited mucoid colonies and tolerance to these two categories of stress agents.     

Synthesis of salt-soluble proteins in barley. Pulse-labeling study of grain filling in liquid-cultured detached spikes

The accumulation of salt-soluble proteins in the endosperm of developing barley (Hordeum vulgare L.) grains was examined. Detached spikes of barley were cultured at different levels of nitrogen nutrition and pulse-labeled with [¹⁴C] sucrose at specific times after anthesis. Proteins were extracted from isolated endosperms and separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and crossed immunoelectrophoresis. Fluorography revealed an early, middle and late synthesis of specific proteins during grain filling. Synthesis of proteins appearing at the later stages responded to increased nitrogen nutrition. Two major components, -amylase and protein Z in particular, had a synthesis profile almost identical to that of the endosperm storage protein, hordein.Abbreviations CIE Crossed immunoelectrophoresis - SDSPAGE Sodium dodecyl sulphate polyacrylamide gel electrophoresis     

Flow sorting from organ material by intracellular markers.

BACKGROUND: Fluorescence-activated cell sorting (FACS) is an attractive technique for gene or protein expression studies in rare cell populations. For cell types where specific surface markers are not known, intracellular markers can be used. However, this approach is currently held to be difficult, as the required fixation and permeabilization may cause protein modification and RNA degradation. METHODS AND RESULTS: Using the rat thyroid gland as model, rare (parafollicular) and frequent (follicular) endocrine cell types were sorted based on immunostaining for intracellular calcitonin peptide and thyroglobulin protein expression. The sorted cells were compatible with Western blot analysis of proteins, immunoassay detection of calcitonin peptide hormone and RT-PCR. CONCLUSION: We developed a robust FACS protocol that allows flow sorting of rare cells from dissociated organ material, based on intracellular markers. Our FACS protocol is compatible with downstream analysis of proteins, peptides, and mRNA in the sorted cells.