Construction and properties of an integrable plasmid for Bacillus subtilis.

A plasmid useful for locating the chromosomal site of cloned DNA fragments that lack intrinsic genetic activity, for insertional mutagenesis, for single-copy complementation, and for dominance studies was constructed. Some plasmids containing Bacillus subtilis DNA were only active in transformation when the tetracycline resistance determinant of the plasmid was inactivated. The results suggest that production of the tetracycline gene product is lethal to B. subtilis.     

Lobster claw motorneurons respond to contralateral sensory stimuli.

Unilateral sensory stimuli in an isolated lobster claw--ganglion preparation elicits soma and axon spikes in homologous motorneurons in the ipsilateral as well as the contralateral hemiganglion. This cross excitation of the motorneurons provides a basis for bilateral reflexes in the claw and is likely mediated through interneuron(s).     

Terminally redundant deletion mutants of bacteriophage BF23.

Deletion mutants of bacteriophage BF23 were isolated and the positions of the deletions were determined. Two different deletable regions were detected: one in the same region as previously reported for bacteriophage T5, which is closely related to BF23; and the other within both terminal repetitions. The former deletable region lay between positions 0.31 and 0.36, which represented the fractional lengths of the BF23 ( + ) DNA as measured from its left end. The latter deletion was evenly divided between the two terminal repetitions. The deletion in the left terminal repetition lay between positions 0.044 and 0.078 and was repeated in the corresponding region of the right terminal repetition between positions 0.966 and 1.0. The size of the DNA transferred to host cells during the first step of DNA transfer by BF23 carrying deletions in the terminal repetitions of its DNA was less than the size of DNA transferred during the first step by wild-type BF23 by an amount equal to the size of the deletion in each terminal repetition. This finding suggests the existence of a specific mechanism for delineating the position at which the first step of DNA transfer is stopped.     

The covalent structure of calf skin type III collagen. IV. The amino acid sequence of the cyanogen bromide peptide alpha 1(III)CB5 (positions 552--788).

The cyanogen bromide peptide alpha 1(III)CB5 is 237 amino acid residues in length and occupies position 552--788 along the alpha 1(III) chain. For sequence analysis alpha 1(III)CB5 was fragmented with hydroxylamine, protease from Staphylococcus aureus V8, trypsin and the arginine-specific enzyme from mouse submaxillary gland. The peptides obtained were separated using molecular and ion exchange chromatography and sequenced with the automated Edman degradation procedure.     

The chemical environment of tubificid and lumbriculid worms according to the pollution level of the sediment

In Lake Geneva (Switzerland), 14 tubificid and 2 lumbriculid worm species were collected in a total of 170 samples of sediment. The sediment was analysed through ten chemical variables: organic carbon, total phosphorus, Cd, Zn, Sn, Pb, Hg, Cu, Cr, Mn. The chemical environment characterizing the presence of every worm species was defined by the mean value of each of these ten variables in all samples where the species was found. The multivariate comparison of the chemical environment typical of every species enabled six groups of species to be distinguished, each characterized by the high value of one chemical variable: (1) Peloscolex ferox, Potamothrix hammoniensis, Limnodrilus claparedeanus, and Cd. (2) Psammoryctides barbatus, and Zn. (3) Limnodrilus hofmeisteri, L. udekemianus, L. profundicola, and total P. (4) Potamothrix heuscheri, Aulodriluspluriseta, A. limnobius, Tubifex tubifex, Ilyodrilus templetoni, Stylodrilus heringianus, and organic C. (5) Potamothrixvejdovskyi, and, Hg. (6) Peloscolex velutinus, Stylodrilus lemani, and Mn. Pollution level of the sediment decreased from group 1 to 6, so each of these groups may be used to define a different level of pollution. The pooled coefficient of variation of the ten chemical variables used to define the chemical environment of each species diminished from group 1 to 6: the most opportunistic species colonized the most polluted areas.     

G6PD Vientiane: A new glucose-6-phosphate dehydrogenase variant with increased stability

Summary A new G6PD variant, called G6PD Vientiane, has been discovered in a patient from Laos.The characteristics of this variant are: mild enzyme deficiency (about 50% of the normal activity) in the granulocytes and the red cells, with normal G6PD-related antigen concentration; increased stability; normal Km glucose 6-phosphate and NADP⁺; increased inhibition constant by NADPH; decreased inhibition by ATP; slightly increased utilization of the substrate analogue; abnormal pH curve, with maximum activity at pH 9.5; slightly reduced starch gel electrophoretic migration. The implications of the molecular stability of a deficient mutant variant are discussed.     

Relationship between the golgi apparatus, gerl, and secretory granules in acinar cells of the rat exorbital lacrimal gland

The method of secretory granuleformation in the acinar cells of the rat exorbital lacrimal gland was studied by electron microscope morphological and cytochemical techniques. Immature secretory granules at the inner face of the Golgi apparatus were frequently attached to a narrow cisternal structure similar to GERL as described in neurons by Novikoff et al. (Novikoff, P. M., A. B. Novikoff, N. Quintana, and J.-J. Hauw. 1971. J. Cell Bio. 50:859-886). In the lacrimal gland. GERL was located adjacent to the inner Golgi saccule, or separated from it by a variable distance. Portions of GERL were often closely paralleled by modified cisternae of rough endoplasmic reticulum (RER), which lacked ribosomes on the surface adjacent to GERL. Diaminobenzidine reaction product of the secretory enzyme peroxidase was localized in the cisternae of the nuclear envelope, RER, peripheral Golgi vesicles, Golgi saccules, and immature and mature secretory granules. GERL was usually free of peroxidase reaction product or contained only a small amount. Thiamine pyrophosphatase reaction product was present in two to four inner Golgi saccules; occasionally, the innermost saccule was dilated and fenestrated, and contained less reaction product than the next adjacent saccule. Acid phosphatase (AcPase) reaction product was present in GERL, immature granules, and, rarely, in the innermost saccule, but not in the rest of the Golgi saccules. Thick sections of AcPase preparations viewed at 100 kV revealed that GERL consisted of cisternal, and fenestrated or tublular portions. The immature granules were attached to GERL by multiple connections to the tublular portions. These results suggest that, in the rat exorbital lacrimal gland, the Golgi saccules participate in the transport of secretory proteins, and that GERL is involved in the formation of secretory granules.     

Autologous and allogenic human rosettes]

A proportion of human peripheral blood T lymphocytes have the property to form spontaneous rosettes in vitro with autologous and allogeneic red blood cells. In our experience the percentage of allo-rosettes is higher than the percentage of auto-rosettes. Red blood cells of the Bombay type are capable of binding to allogeneic lymphocytes. However a low percentage of auto-rosettes was found in the Bombay donor.     

Bacillus megaterium mutant deficient in membrane-bound adenosine triphosphatase activity.

An adenosine triphosphatase (ATPase) mutant of Bacillus megaterium was isolated and characterized. This mutant (designated A37) was unable to grow on nonfermentable carbon sources and possessed less than 5% of the wild-type ATPase activity. Oxygen uptake by the mutant was comparable to that in the wild type. Sporulation in the wild type occurred in both glucose- and nitrogen-limiting media; however, A37 sporulated only in the nitrogen-limiting medium. The inability of A37 to sporulate in glucose-limiting medium seemed to be due to insufficient adenosine 5'-triphosphate (ATP) levels during the sporulation stages. Fructose, which can generate ATP via substrate-level phosphorylation, is equally efficient in stimulating ATP synthesis in the wild type and A37. Malate-stimulated ATP synthesis in the wild type was shown to have many characteristics associated with oxidative phosphorylation and was absent in the mutant. These data suggest that the ATPase deficiency results in the loss of oxidative phosphorylation.     

Mutants of Bacillus megaterium resistant to uncouplers of oxidative phosphorylation.

Mutants of Bacillus megaterium displaying malate-stimulated ATP synthesis resistant to uncouplers of oxidative phosphorylation were isolated and partially characterized. ATP synthesis in such mutants was resistant to carbonyl cyanide m-chlorophenyl hydrazone as well as to other uncouplers including 2,4-dinitrophenol, pentachlorophenol, and sodium azide. ATP synthesis in the wild type and in resistant mutants was sensitive to N,N'-dicyclohexylcarbodiimide, tributyltin, valinomycin plus potassium, and potassium cyanide. Active transport of glycine and glutamine which are sensitive to uncouplers in the wild type was also uncoupler-sensitive in the mutants.