EDTA- and puromycin-derived duck- and rabbit globin-messenger ribonucleoprotein complexes isolated by oligo(dT)-cellulose chromatography

Duck- and rabbit globin messenger ribonucleoprotein complexes isolated by oligo(dT) cellulose chromatography reveal an identical protein pattern—two main proteins of molecular weights of 73000 and 49000 daltons and minor components—whether the complexes have been liberated from polyribosomes with the EDTA-or the puromycin-high-salt method. In the globin messenger ribonucleoprotein particles of both species predominantly the protein with a molecular weight of 73000 daltons is attached to poly(A)-containing regions of the messenger RNAs.     

Identification and quantification of juvenile hormones from different developmental stages of the cockroach Nauphoetacinerea

By the combined use of high-pressure liquid chromatography, $\text{Galleria}$ bioassay and gas chromatography/ chemical ionization/mass spectrometry we were able to isolate and identify the three known natural juvenile hormones (JHs) from haemolymph extracts of larval and adult females of the cockroach $\text{Nauphoeta}$$\text{cinerea}$. This is the first demonstration of the simultaneous occurrence of the three JHs in the same insect and the first time JH I and II have been identified in a hemimetabolous insect. Quantitative investigations show that the composition of the three JHs is different at different developmental stages. The haemolymph of larvae contains a high percentage of JH I and II, whereas the haemolymph of adult females in the oocyte maturation stage contains mostly JH III. This suggests more juvenilizing functions for JH I and II and more gonadotropic functions for JH III.     

Extractable Lipids of Gram-Negative Marine Bacteria: Phospholipid Composition

Phospholipid compositions of 20 strains of marine and estuarine bacteria were determined. Results showed that phospholipids of marine bacteria differed very little from those of nonmarine organisms with phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol being the predominant phospholipids in all strains examined. Lyso-phosphatidylethanolamine occurred in significant quantities among a number of the marine bacteria, and two of the isolates contained significant quantities of poly-beta-hydroxybutyrate. Effects of age and growth temperature on the phospholipid composition were also investigated. It is suggested that phylogenetic relationships among bacteria may be correlated with phospholipid composition.     

Specific locus mutation rates after repeated small radiation doses to mouse oocytes

When female mice were given a dose of 20 × 10 rad X-rays, the specific locus mutation rate among offspring conceived up to 7 weeks after the end of treatment was 1/39887 or 0.18·10⁻⁷/rad/locus, whereas when the same total dose of 200 rad was given in a single exposure the mutation rate was 9/34813 or 1.85·10¹⁰⁻⁷/rad/locus. The lower mutation rate after the 20 × 10 rad dose was obtained whether the total of 200 rad was given over a period of 5 days or 4 weeks, and if only young conceived in the first 20 days, rather than 7 weeks, were considered. It is suggested that each 10 rad fraction had the same small effect, and hence that these results confirm and extend Russell's previous finding that the dose-response relationship for specific locus mutations in females is curved.     

Phytochrome-induced flavonoid biosynthesis in mustard (Sinapis alba L.) cotyledons. Enzymic control and differential regulation of anthocyanin and quercetin formation

Phytochrome-induced increases in enzyme activities for phenylalanine ammonia-lyase (EC 4.3.1.5) and chalcone isomerase (EC 5.5.1.6), and in amounts of the related end products, anthocyanin and the flavonol, quercetin, were measured in cotyledons of mustard (Sinapis alba L.). There was no correlation between the activities of these enzymes and the rate of anthocyanin accumulation; however, some correlation was found with the quercetin accumulation rate. Since anthocyanin and flavonol accumulation is spatially separated in mustard (flavonols in the upper epidermis, anthocyanin in the lower epidermis), it was possible to measure anthocyanin-associated phenylalanine ammonia-lyase independently. This activity correlated well with the accumulation rate for anthocyanin during the first few hours after induction. The phytochrome effect on anthocyanin formation differed from that on quercetin formation: anthocyanin was strongly induced by continuous far-red light and by both continuous red light and red light pulses, whereas quercetin was only effectively induced by continuous far-red light.Abbreviations CHI chalcone isomerase - PAL phenylalanine ammonia-lyase     

Ecology and taxonomy of chitinoclasticCytophaga and related chitin-degrading bacteria isolated from an estuary

A total of 103 strains of estuarine, Chitinoclastic bacteria isolated from water, and sediment samples collected from the upper Chesapeake Bay, including 17 freshwater and 11 seawater isolates, were subjected to numerical taxonomy analysis. The isolates included 44 yellow-orange pigmented strains classified asCytophaga-like bacteria (CLB) of theCytophagaceae. Salt requirement of the strains ranged from tolerance to 1% NaCl to an absolute requirement for NaCl, with 1% NaCl satisfying this requirement. The largest phenon consisted of facultatively anaerobic, oligo-nitrophilic, and flexirubin pigment-producing freshwater and estuarine isolates, and included reference strains of bothCytophaga johnsonae Stanier andCytophaga aquatilis Strohl and Tait. Other phena, containing a smaller number of strains, comprised marine and estuarine isolates which did not produce flexirubin pigments, and required organic nitrogen for growth and for production of chitinolytic enzymes. Salt-requiring, flexirubin pigment-producing, chitin-degrading strains were, on occasion, isolated from estuarine samples and represented phena found in estuaries. Most of theCytophaga isolates, as well as chitin-degrading species not of the genusCytophaga that were isolated from Chesapeake Bay, clustered in phena representing previously described species of aerobic, zymogenic, chitinoclastic bacteria. When the frequency of occurrence of features related to environmental parameters, viz., pH, salinity, temperature range of growth, and growth on media lacking organic nitrogen, was calculated, ecological groupings of strains in the 2 major phena of CLB could be distinguished among the estuarine, chitin-degrading bacteria.     

Two possible 3-(3,4-dichlorophenyl)-1,1-dimethylurea-insensitive sites in Photosystem II of spinach chloroplasts

Two possible 3-(3,4-dichlorophenyl)-1,1-dimethylurea-insensitive sites were found in PS II of spinach chloroplasts, depending on the pH of the assay medium used. The low site (pH 6) can be inhibited by certain quinolines, such as 8-hydroxyquinoline at concentrations less than 50 μM. The high pH site (pH 8) can be inhibited by disodium cyanamide, folic acid, or 5,6-benzoquinoline at concentrations from 50 μM to 5 mM. With the exception of orthophenanthroline, which stimulates the high pH site but does not show much inhibition at low pH, all other inhibitors gave opposite effects at the pH values used, i.e., they stimulated at low pH or inhibited at high pH, or vice versa. Several mechanisms for the observed effects are discussed.     

Stimulation of electron transport from Photosystem II to Photosystem I in spinach chloroplasts

Electron transport from Photosystem II to Photosystem I of spinach chloroplasts can be stimulated by bicarbonate and various carbonyl or carboxyl compounds. Monovalent or divalent cations, which have hitherto been implicated in the energy distribution between the two photosystems, i.e., spillover phenomena at low light intensities, show a similar effect under high light conditions employed in this study. A mechanism for this stimulation of forward electron transport from Photosystem II to Photosystem I could involve inhibition of two types of Photosystem II partial reactions, which may involve cycling of electrons around Photosystem II. One of these is the DCMU-insensitive silicomolybdate reduction, and the other is ferricyanide reduction by Photosystem II at pH 8 in the presence of dibromothymoquinone. Greater stimulation of forward electron transport reactions is observed when both types of Photosystem II cyclic reactions are inhibited by bicarbonate, carbonyl and carboxyl-type compounds, or by certain mono- or divalent cations.Abbreviations used: DCMU, 3-(3,4-dichlorophenyl)-1, 1-dimethylurea; DCIP, 2,6-dichloroindophenol; DBMIB, 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone; FeCN, potassium ferricyanide; MV, methylviologen; PS I, photosystem I; PS II, photosystem II; SM, silicomolybdic acid.