Detection and mapping of six miniF-encoded proteins by cloning analysis of dissected miniF segments

Various DNA subfragments were derived from miniF DNA by complete or partial PstI cleavage, and cloned in the plasmid vectors pBR322 or lambda dv1. The recombinant plasmids obtained were introduced into an Escherichia coli minicell-producing strain, and the plasmid-coded proteins were radiolabeled and analyzed by gel electrophoresis. Six miniF-encoded proteins, larger than 11 000 daltons, were detected and their coding regions were mapped on the F plasmid genome. Three of them were assigned by taking into account the known nucleotide sequences (Murotsu et al. 1981; K. Yoshioka, personal communication). The coding directions of some proteins were determined by inserting the lac promotor into one of the recombinant plasmids and analyzing the increase in production of the proteins. The coding direction of the five proteins analyzed so far was uniform. Comparison of these results with a functional map of miniF suggested possible roles of the proteins.

Mutual relationship between antibiotics and resting spores of Bacillus subtilis: morphological changes and macromolecular synthesis after germination of spores treated with cyclic polypeptide and aminoglycoside antibiotics

Morphological changes and synthesis of DNA, RNA, protein, and cell wall were investigated during germination of resting spores of Bacillus subtilis exposed transiently to the cyclic polypeptide antibiotics, polymyxin B and gramicidin S, and the aminoglycoside antibiotics, streptomycin, kanamycin, and gentamicin. Normal germinated spores showed breaks of the spore coat, a diminution in size and a fibrillar appearance of the cortex, a swelling core, a cell wall as thick as that of vegetable cells, some mesosomes and DNA fibrils. On the other hand, no breaks of the spore coat, a spore core with a slight swelling and irregular form, a thin cell wall, no demonstration of the nuclear material and no granularity in the cytoplasm were characteristic of the germinated spores derived from polymyxin B- and gramicidin S-treated resting spores. With gramicidin S-treated germinated spores a few vacuoles were formed in the cytoplasm. Both polymyxin B- and gramicidin S-treated germinated spores showed little or no synthesis of DNA, RNA, and protein. The vegetative cells derived from streptomycin-treated resting spores demonstrated several finely granular regions in the cytoplasm and a disorder of the fibrillar nucleoid, and their autolysis occurred early. Their DNA and RNA synthesis was normal, whereas protein synthesis was low. In spite of no occurrence of cell division and very low protein synthesis, the most striking characteristics of the outgrowing cells derived from kanamycin-treated resting spores were a markedly thickened cell wall and a continuous incorporation of labeled D-alanine suggesting cell wall synthesis; RNA synthesis was slightly lower and DNA synthesis was almost normal. The outgrowing cells from gentamicin-treated resting spores also revealed relatively thick cell walls and a very slight incorporation of labeled D-alanine. Their DNA and RNA synthesis was fairly low and protein synthesis was almost completely inhibited. These results coincide with the growth curves of individual antibiotic-treated resting spores.

Mutual relationship between antibiotics and resting spores of Bacillus subtilis: binding of cyclic polypeptide and aminoglycoside antibiotics to spores and their inhibitory effect on outgrowth and vegetative growth

Not only cyclic polypeptide antibiotics such as polymyxin B, colistin and gramicidin S but also aminoglycoside antibiotics such as streptomycin, kanamycin, gentamicin and kanamycin derivatives combined with the resting spores of Bacillus subtilis and inhibited outgrowth or vegetative growth after germination. All the antibiotics other than gramicidin S were released from the resting spores and their inhibitory action was reversed by the addition of Ca2+ and Fe3+. As the above antibiotics have free amino (or guanidine) groups in common, it was assumed that such groups play an important role in binding of the antibiotics to the resting spores. Moreover, it was shown that protamine and poly-L-lysine were also bound to the resting spores and were released from them by Ca2+. On the other hand, free carboxyl groups had been demonstrated in the outermost surface of the resting spores in a previous study. Thus, we assume that the mode of binding of the antibiotics to the resting spores may be due to the formation of reinforced ionic bonds between amino (or guanidine) groups in the antibiotics and carboxyl groups on the spore surface.

Construction and some properties of packageable plasmid F

A derivative of plasmid F which is packageable in lambda phage coat was constructed using techniques of in vitro recombination. This plasmid is composed of three DNA fragments generated by restriction enzyme EcoRI: a miniF fragment (fragment f5 of F'lac) which is able to replicate autonomously, a DNA fragment from Staphylococcus plasmid that carries the beta-lactamase gene, and a portion of guaA (B) transducing lambda phage DNA carrying lambda cohesive ends (cos site) along with almost all the late genes but devoid of all those genes and sites that are needed for replication, regulation, and recombination. The hybrid plasmid has a molecular weight of 2.7 x 10(7) daltons, about 84% size of lambda phage genome, and can be packaged in lambda coat when helper phage replicates in the plasmid-carrier cell. The packaged plasmid and the helper lambda phage particles are separated by CsCl density gradient centrifugation. The replication characteristics of the recombinant plasmid are all those of F including the copy number, incompatibility, and curing with acidine orange. The packaged plasmid is injected into an F- cell and establishes a plasmid state with normal efficiency. In F+ or Hfr cells, the resident F factor hinders this process.

47,+(9q-) in unrelated three children with plasma growth hormone deficiency

Marker chromosomes carried by unrelated 3 cases were identified as a part of No. 9 chromosome through the analysis of the chromatid fine structure after trypsin-giemsa treatment. They showed characteristic features of that 9p trisomic syndrome which were described by Rethoré et al. (1973). In addition to those features, some clinical and laboratory findings on growth hormon deficiency were disclosed in this report.