ALBERT

Notes: Two glyceryl ethers, 1-O-hexadecyl glycerol and 1-O-cis-octadec-11-enyl glycerol, chimyl and paramecyl alcohol respectively, were quantified in total phospholipids and five glycerophospholipid classes from cells and cilia of the ciliated protozoon Parammecium tetraurelia. The ether content of 2-aminoethyl phosphonoglycerolipid was 85–90 mole %. Concentrations of ethers were greatest in the ethanolamine phosphonolipids 〉 phosphatidylcholines 〉 phosphatidylserines 〉 phosphatidylethanolamines 〉 phosphatidylinositols. The glyceryl ether concentrations in total cellular phospholipids increased with culture age in P. tetraurelia and P. multimteronucleatum cells. The glyceryl ether concentrations in the phospholipids of P. tetraurelia cilia remained constant from mid log to stationary phase of culture growth. Paramecium tetraurelia phospholipid glyceryl ether concentrations were made greater by supplementation of cultures with chimyl alcohol.

Notes: SUMMARY. 1. Single-station diel oxygen curves were used to monitor the oxygen metabolism of the Ogeechee River, a sixth-order blackwater river in the Coastal Plain of southeastern U.S.A., over a period of 4 years. Ecosystem production (P) and respiration (R) were estimated, and P/R ratios calculated to determine the extent of autotrophy characteristic of this type of river. The potential error in oxygen metabolism caused by photo-oxidation of dissolved organic carbon (DOC) in the water was measured and found to be minor.2. Rates of ecosystem primary production measured were intermediate compared to other rivers, ranging from 0.49 to 13.99g O2m−2 day −1.Primary production rates were highest during the summer when water levels were low. Regression analysis indicated that water depth and light absorption by DOM were significant predictors of primary production in this river. Incident light intensities were not significantly correlated with production rate.3. Respiration rates were unusually high, varying between 3.70 and 11.5 g O2 m−2 day − 1. System respiration also varied seasonally, but less than primary production. Rates were slightly higher in spring and summer.4. With one exception, P/R ratios were considerably lower than l throughout the study period, indicating that the Ogeechee River was highly heterotrophic. PIR ratios ranged from 0.09 to 1.3, and averaged 0.25.5. A carbon budget calculated for this river showed floodplain inputs were 7 times autochthonous production. Organic carbon turnover length was 690 km, considerably longer than has been reported for lower-order rivers.

Notes: Zusammenfassung. Es wurde die DNS- und RNS-Biosynthese von Neurospora crassa Wildstamm 3a6A unter Einfluss unterschiedlicher Konzentrationen von 2,4-D, Amitrol, Atrazin, Chlorpropham und Chlorflurenol untersucht. Die Variation der Herbizide erfolgte von 10−3 bis 10−6 M. Der in beliifteten Kulturen gezüchtete Pilz ist gegenuber Chlorpropham am empfindlichsten. Bei 10−3 M ist die Toxizitätsgrenze überschritten und das Wachstum vollständig gehemmt. 2,4-D hat in einer Konzentration von 10−3 M den grössten Einfluss auf die Nucleinsäure-Biosynthese. Die DNS-Werte erhöhen sich gegenüber der Kontrolle aiif 140%. Unter Einfluss von Atrazin (10−3 M) scheint besonders die Protein-Synthese stimuliert zu werden. Die Zunahme beträgt hier fast 140%. Allgemein haben die untersuchten 5 Herbizide einen relativ geringen Einfluss auf die Nucleinsäure-Biosynthese. Ein grösserer Effect ist nur bei der höchsten Herbizid-Konzentration von 10−3 M ZU erkennen. Der Pilz ist gegenüber diesen Herbiziden wenig empfindlich. Effets des herbicides 2,4-D, aminotriazole, atrazine, chlorprophame et chlorflurénol sur la biosynthése de l'acide nucléique chez un ascomycéte; Neurospora crassaRésumé. La biosynthése de l'ADN et de l'ARN fut déterminée chez la race sauvage 3a6A de Neurospara crassa, cultivé sur des milieux contenant du 2, 4-D, de l'aminotriazole, de l'atrazine, du chlorprophame et du chlorflurenol à des concentrations de 10−3 a 10−6 M. En culture aéréc, JV. crassa fut plus sensible au chlorprophame et à 10−3 M. sa croissance fut complétement inhibée. L'effet le ptus marqué sur la biosynthésc de I'acide nucléique fut observé avec lc 2,4-D à 10−3 M. concentration qui porta la teneur en ADN à 140% de celle du téemoin. Avec l'atrazine à 10−3 M. la synthése des proteines en particulier sembla stimulée jusqu’à atteindre environ 140% du témoin. En général, les cinq herbicides etudids n'eurent qu'un effet relativement faibie sur la biosynthése de l'acide nucléique; seule la concentration la plus forte, 10−3 M. cut un effet appreciable. N. crassa ne se montra pas tres sensible à ces herbicides. Effects of the herbicides 2,4-D, aminotriazole, atrazine, chlorpropham and chlorflurenol on nucleic-acid biosynthesis in the ascomycete Neurospora crassaSummary. Biosynthesis of DNA and RNA was determined in Neurospora crassa wild race 3a6A grown in cultures containing 2,4-D, aminotriazole, atrazine, chlorpropham and chlorflurenol in concentrations of 10−3-10−6 M. In aerated culture, N. crassa was most sensitive to chlorpropham and at 10−3 M growth was completely inhibited. The greatest effect on nucleic-acid biosynthesis was given by 2,4-D at 10−3 M which increased the DNA value to 140% of the control. With atrazine at 10−3 M. protein synthesis in particular appeared to be stimulated, to almost 140% of the control. In general, the five herbicides studied had a relatively slight effect on nucleic-acid biosynthesis; only with the highest concentration of 10−3 M was the effect appreciable. N. crassa was not very susceptible to these herbicides.

Notes: The expression of the Neisseria gonorrhoeae opacity protein (Op, protein II), a major antigenic determinant of the outer membrane, is subject to frequent phase transitions. At least nine expression loci (opaE) are involved in the production of a large number of serologically distinct Op types. Using opa-specific oligonucleotides as probes in genomic blots, we detect Op-related gene sequences (opr) in N. meninglitidis as well as in N. lactamica. DNA sequence analysis of such opr genes derived from N. meninglitidis reveals distinct regions of homology with gonococcal opa E genes. As shown in the immunoblot, the proteins encoded by ops and opr are serologically related. Like the opa E genes, the 5′-coding sequences of the opr genes include a repetitive sequence composed of pentameric CTCTT units. The number of these coding repeat (CR) units is variable. This finding, together with the observation that all opr genes are constitutively transcribed, regardless of the status of protein production, suggests a translational control mechanism identical to that of the opa genes in gonococci. The related structures and control mechanisms of opa and opr genes imply a general significance of their gene products for the pathogenic character of the investigated Neisseria species.

Notes: Abstract. The eggs of 30 female chinook salmon, Oncorhynchus tshawvtscha (Walbaum), were collected at spawning. Some eggs from each fish were collected for bacteriologic study. Two salmon produced eggs judged to be of poor quality which were not used. The remaining 28 of the 30 groups of eggs were fertilized from a single sperm pool and the eggs incubated in separate groups. Mortality data on the developing salmon were recorded regularly through the twelfth week on feed. Unfertilized eggs from each group were surface-disinfected with an iodine solution, then crushed and subjected to a culture procedure designed to permit growth of as many bacterial types as possible. Bacteria were cultured and identified, and a comparison made of the types of organisms present in eggs from groups which later incurred high or low mortalities. Bacteria were recovered from both groups of salmon eggs. Although no single organism could be identified as a cause of increased mortality, the more frequent occurrence in the eggs of the ‘high mortality’ group of species of Vibrio, Listeria, Corynebacterium and Staphylococcus suggests that these bacteria may play a role. It is suggested that the cause of so-called early lifestage disease of salmon is multifactorial.

Notes: : The underwater light field of eight central New York lakes, which represent a wide range of trophic state, was characterized through paired measurements of Sechi disc transparency (SD, m) and diffuse light attenuation (Kd, m−1). A total of 90 paired measurements are included in the data base. Substantial variability in the Kd SD product with time within individual systems, and amongst systems, was observed, which indicates differences in the relative contributions of absorption and scattering to attenuation. More than 50 percent of the temporal variability in Kd was attributable to attendant variations in chlorophyll a (C, mg m−3) in only two of the lakes. Estimates of the adsorption (a, m−1) and scattering (b, m−1) coefficients based on paired Kd and SD measurements compared well with more precise determinations available for one of the lakes. Determinations of a and b for the eight lakes, from SD and Kd measurements, indicated great system-specificity and temporal variability in these characteristics. The temporal variability in relative contributions of a and b to Kd is consistent with covariation of different attenuating components and the lack of correlation between C and Kd in most of the study lakes.