The malmö polymorphism of coagulation factor IX, an immunologic polymorphism due to dimorphism of residue 148 that is in linkage disequilibrium with two other F.IX polymorphisms

A mouse monoclonal antibody (MAB 9.9) to coagulation factor IX (F.IX) detects a polymorphism in the plasma of normal people. Its epitope has been narrowed down to <6 amino acids in the activation peptide of the X-linked F.IX protein. The activation peptide contains a dimorphism—Thr:Ala—at position 148 of the protein. Using synthetic oligonucleotides, we have demonstrated that (1) the F.IX which reacts with 9.9 has Thr at position 148 and (2) that which does not has Ala. Positive reactors (148^thr) are designated Malmö A, and negative reactors (148^ala) are designated Malmö B. The plasma levels of AA women are indistinguishable from those of A men, and both B men and BB women are null against MAB 9.9. The plasma level of Malmö A in AB women is approximately half that of AA women, and “lyonization” is clearly operating in the heterozygotes. The dimorphism is in strong linkage disequilibrium with two other intragenic RFLPs, TaqI and XmnI. Furthermore, intragenic crossing-over—including double crossing-over—appears to have occurred between the three sites. Seven of the eight possible haplotypes have been identified, five in men and two others in women. The immunoassay that identifies ～50% of the AB women in the pool of Malmö A females with 95% confidence identifies men unambiguously as A or B. The assay would be very useful for population-genetic studies of the Malmö epitope if the studies were limited to men.     

Synthesis of dinucleoside tetraphosphates by RNA polymerase B (II) from calf thymus

Highly purified RNA polymerase B (II) from calf thymus catalyses the synthesis of dinucleoside tetraphosphates from ribonucleoside triphosphates in the absence of an oligonucleotide primer or additional protein factors. The reaction requires a DNA template and bivalent cations such as Mn2+ or Mg2+. It is strongly inhibited by heparin and high concentrations of alpha-amanitin but not by rifampicin. On a given template various dinucleoside tetraphosphates of different sequence are formed although the yield depends on the nature of the template.     

Mutants with Altered Ca2+-Channel Properties in PARAMECIUM TETRAURELIA: Isolation, Characterization and Genetic Analysis

Dancers are a group of mutants in Paramecium tetraurelia whose Ca²⁺ current inactivates poorly and are likely to be defective in the structure of their Ca²⁺ channels. These mutants show prolonged backward swimming in response to K⁺ and Ba ²⁺ in the medium and were selected by this property in a galvanotactic trough. The dancer mutants are semidominant, and all isolated mutants belong to one complementation group; they are not allelic to any of the previously isolated behavioral mutants of P. tetraurelia. The phenotypic change from the homozygous parent to heterozygous F₁ generation takes three to five fissions. There is no evidence of a cytoplasmic factor capable of converting the dancer to the wild-type phenotype, as has been demonstrated in the mutants pawn and cnr. We suggest that the dancer locus is a structural gene for the Ca²⁺ channel.     

Extremely short 20-33 nucleotide introns are the standard length in Paramecium tetraurelia.

Paramecium tetraurelia has the shortest known introns as its standard intron length. Sequenced introns vary between 20 and 33 nucleotides in length. The intron sequences were discovered in genomic sequences coding for a variety of different proteins, including phosphatases, kinases, and low-molecular weight GTP-binding proteins. All intron sequences begin with the conserved dinucleotide GT and end with the conserved dinucleotide AG. The sequences are more AT rich than the Paramecium coding sequences. The identified sequences were confirmed as introns by sequencing several cDNA fragments. We report here analysis of the characteristics of 50 separate introns, including size, base composition, and a consensus sequence.     

Opa-like repeats in the genome of the Medfly Ceratitis capitata

The sequence determination of several genomic clones isolated from the Mediterranean fruitfly Ceratitis capitata identified the existence of opa-like repeats, often more than one being clustered in small chromosomal segments. These repeats have previously been shown to consist of stretches of tandemly reiterated glutamine-encoding residues, and they are found in multiple genes of several organisms. Most of the repeats described here are flanked or interrupted by stop codons in all reading frames and, thus, could not possibly be part of protein-coding sequences. Furthermore, these repeats, of which there are several hundred in the genome of the Medfly, can be used effectively for the determination of sequence polymorphisms, providing a convenient approach to obtain additional landmarks for the construction of genomic maps of this economically important insect.This paper is dedicated to the memory of our colleague and friend Dr. Jim Flach who took part in the initial phase of this work and died during the course of the investigation.     

Morphologische und statistische Untersuchungen an Zellkernen von Ratten und Mäusen zur Frage einer cytologischen Geschlechtsdiagnostik

Zusammenfassung An Blutausstrichen und Gewebsschnitten von männlichen und weiblichen Mäusen und Ratten wurde das Vorkommen von geschlechtsspezifischen morphologischen Kernmerkmalen untersucht. Die Kerne der neutrophilen Granulocyten weisen bei beiden Arten keine an den Kernanhängen erkennbare Geschlechtsdifferenz auf. An den Kernen der Parenchymzellen wurde für weibliche und auch für männliche Tiere ein positiver Geschlechtsnachweis auf Grund einer charakteristischen Chromatinverteilung geführt.Wir stimmen dem Vorschlag von Th. Lüers (1957) zu, die Begriffe Geschlechts-bestimmung und Geschlechtsdifferenzierung nur in ihrer ursprünglichen Bedeutung zu verwenden.     

Evaluation of the use of cyclodextrins in chiral separation of basic drug substances by capillary electrophoresis

The influence of the choice of type and/or concentration of cyclodextrin, other additives, the temperature surrounding the capillary, and buffer pH on the separation of some chiral basic drug substances in capillary zone electrophoresis has been evaluated. It was found that pH of the buffer and type and concentration of cyclodextrin had a major influence on the separation. © 1995 Wiley-Liss, Inc.     

Polyol accumulation by two filamentous fungi grown at different concentrations of NaCl

The accumulation of polyols by Aspergillus niger (van Tiegh) strain S 1 and Penicillium chrysogenum (Thom) strain S 30 was followed during growth in media of different concentrations of NaCl. The major polyols found were glycerol, erythritol and mannitol. The total polyol pool increased in both organisms in response to raised salinity, and the proportion of glycerol and erythritol was markedly enhanced at high salinity.     

Multi-system approach to study mutagenesis induced by chemical carcinogens.

To understand molecular mechanisms of the mutation fixation process induced by a mutagen and carcinogen, a multi-system approach is suggested to reduce the probability that the results are biased by the assay used. In this light we described our different approaches to answer basic questions on the mutagenesis induced by the chemical carcinogen 4-Nitroquinoline-1-oxide. We determined mutations at the molecular level in three experimental systems: a) in prokaryotes (ss M13mp19 lacZ'/E. coli F'lacZ delta M15); b) in eukaryotes (i) ss and ds pZ189 supF/CV1-P/E.coli lacZam and (ii) HPRT in CHO cells with different repair capacity. We think this type of approach can be used to study the genetic effects of new cancer drugs for which the molecular mechanisms of action at the molecular level are still not well understood. We think to apply the know-how to study mutational spectra in tumor derived tumor suppressor genes.