Divided and undivided compound eyes in Ascalaphidae (Insecta, Neuroptera) and their functional and phylogenetic significance

The external morphology of the compound eyes of 13 species of the Ascalaphidae family (Insecta, Neuroptera) from Africa, Asia and Europe was studied in relation to the habitat, phylogeny and time of activity during the day. The six species with undivided eyes (Haplogleniinae) are nocturnal; four inhabit more or less open terrain, while two inhabit more or less dense vegetation. Of the seven species with divided eyes (Ascalaphinae), three are diurnal, one is crepuscular and nocturnal, and three are nocturnal. It was found that two of the diurnal species inhabit open terrain and open forest, and one inhabits dense vegetation; the crepuscular and nocturnal species inhabits open terrain; and two of the nocturnal species inhabit open terrain, while one inhabits dense vegetation. The results are discussed in relation to the hypothesis that divided eyes evolved from undivided eyes, originally serving as an adaptation to daytime vision in open terrain.     

Quantitative Large-Volume Sampling Technique

A filtration technique for high-volume sampling of water has been developed that, when combined with the most probable number procedure, permits the quantitation of microorganisms present at very low densities.     

Analysis of the proteins in thymocyte plasma membrane and smooth endoplasmic reticulum by sodium dodecylsulfate-gel electrophoresis

We have purified the plasma membranes and membranes of endoplasmic reticulum from calf and rabbit thymocytes and from calf mediastinal lymph node lymphocytes. We disrupted the cells by the “nitrogen cavitation method” and prepared a microsomal isolate by differential centrifugation. We fractionated this by isopycnic ultracentrifugation in dextran gradients into membrane vesicles, PM₁ and PM₂, most likely derived from plasma membrane and a fraction, ER, most likely originating from endoplasmic reticulum. More than 80% of the microsomal 5′-nucleotidase and acid p-nitrophenylphosphatase concentrates in the PM₁ and PM₂ fractions; alkaline p-nitrophenylphosphatase, another presumptive PM marker, is concentrated in the PM₁ fraction. These data are confirmed by the lacroperoxidase radioiodination of intact rabbit thymocytes followed by subcellular fractionation. The specific content of phospholipids (822 nmoles/mg protein) and cholesterol (1032 nmoles/mg protein) is highest in PM₁ and PM₂ plasma membrane fractions. NADH-oxidoreductase, our endoplasmic reticulum marker, is clearly enriched in gradient pellet.The membrane proteins were separated by electrophoretic molecular sieving in sodium dodecylsulfate-polyacrylamide gel electrophoresis, containing dithiothreitol (sodium dodecylsulfate-polyacrylamide gel electrophoresis). We numbered the 10 major protein components of the “microsomal fraction” (apparent molecular weights between 280000 and 15000) from 1–10 according to their decreasing molecular weights. Of these proteins, those with higher molecular weight, predominantly glycoproteins, appear in the PM₁ fraction, while the endoplasmic reticulum fraction contains mainly low molecular weight components.     

Interaction of muscle glycogen phosphorylase with pyridoxal 5'-methylenephosphonate

Rabbit muscle glycogen phosphorylase (EC 2.4.1.1) was reconstituted with pyridoxal 5′-methylenephosphonate with ca. 25% restoration of enzymatic activity. The modified enzyme has very similar chemical and physical properties to native phosphorylase including UV and fluorescence spectra, quaternary structure, high energy of activation in the reconstitution reaction, optimum pH and susceptibility to phosphorylase kinase in the b to a conversion. While V_max is reduced to ca. one-fifth, affinities for the substrate glucose 1-P and the effector AMP are increased. This is the first analog of pyridoxal 5′-P modified in the 5′-position found to restore catalytic activity to apophosphorylase.     

Synthèse, à partir du D-galactose,d'un dérivé protégé de la célestosamine (6-amino -6,8-didésoxy-7-0-méthyl-D-érythro-D-galact o-octose), sucre de certains antibiotiques du groupe de la lincomycine

Treatment of 1,2:3,4-di-O-isopropylidene-α-D-galactopyranuronyl chloride with diazoethane gave a diazoketone that was converted with methanol in the presence of boron trifluoride into a mixture of keto-ethers. One of these keto-ethers was transformed by reduction of its oxime and N-acetylation into a blocked derivative of celestosamine, which was found to be identical with 5 prepared from a natural source, i.e. lincomycine. The properties of the other two keto-ethers are in agreement with a (D or L)-glycero-L-altro configuration (14) for one of them, and with the presence of a 3-oxetanone ring in the structure (18) of the other one.