O-Dealkylation of coumarin and resorufin ethers by unicellular green algae: kinetic properties of Chlorella fusca and Chlorella sorokiniana

O-Dealkylations of resorufin and coumarin ethers, mediated by microsomal cytochrome P450 mono-oxygenases from animals, plants and microorganisms, are shown here to be performed also by intact cells of the unicellular green algaeChlorella fusca andChlorella sorokiniana. The activity of theO-dealkylation of these ethers was up to tenfold higher withChlorella sorokiniana. Both algae dealkylated methyl-, ethyl-, and pentylethers of resorufin and coumarin. Dealkylation in vivo indicated efficient absorption of methoxy- and ethoxyresorufin, confirmed by the respective absorption kinetics. Piperonylbutoxide and 1-aminobenzotriazole, known inhibitors of plant and mammalian cytochrome P450s, significantly inhibited theO-dealkylase activity of both algal strains. The use of synchronized cultures of both algae revealed that efficiency ofO-dealkylation depends on the stage of the cell cycle: during the growth phase, theO-dealkylase activities increased more than proportional, and the distinct drop in activity during the last hours of the light period indicated the appearance of an endogenous substrate.     

Secondary sensory cells in the gravity receptor system of the statocyst of Octopus vulgaris

Summary The presence of secondary sensory cells in the Octopus gravity receptor system has been demonstrated. In serial thin sections of the receptor cells (hair cells) no axons were found leaving the cells. Instead, synapses were observed with synaptic vesicles lying inside the receptor cells. Both data clearly indicate that the receptor hair cells represent secondary sensory cells. In addition, efferent contacts to the receptor cells could be confirmed.This work was supported in part by grant Wo 160/5 of the Deutsche Forschungsgemeinschaft to Prof. Dr. H.G. WolffThe experimental work was done in part at the Zoological Station in Naples and at the Sechenov Institute of Evolutionary Physiology and Biochemistry of the USSR Academy of Sciences (Laboratory of Prof. Dr. Ya.A. Vinnikov), Leningrad, USSR. The authors thank Prof. Vinnikov and Dr. Tsirulis for stimulating discussions     

Allele frequencies and linkage disequilibrium of polymorphic DNA markers of the Huntington disease region in the German population

Allele frequencies of 14 different restriction fragment length polymorphisms from 12 DNA markers within the Huntington disease (HD) region were evaluated in the German population. No significant differences from published data of allele frequencies from chromosomes of Caucasian ancestry were found. The analysis of eight DNA polymorphisms in 87 HD families of German origin revealed significant non-random association with the HD locus and the D4S95 locus (p674/AccI/MboI), a result that is consistent with all other published studies. These results are confirmed by the fact that the HD gene maps to this region.     

A new species ofPalaeospinax (Chondrichthyes,Neoselachii) from the Lower JurassicPosidonia Shale of Southern Germany

The diagnosis of the fossil neoselachian genusPalaeospinax Egerton 1872 is revised. A new species from the Lower ToarcianPosidonia Shale of Southern Germany is described asPalaeospinax politus n. sp. It differs from all other known members of the genus in having smooth anterior and lateral teeth.     

Red Food Coloring Stain: New,Safer Procedures for Staining Nematodes in Roots and Egg Masses on Root Surfaces

Acid fuchsin and phloxine B are commonly used to stain plant-parasitic nematodes in roots and egg masses on root surfaces, respectively. Both stains can be harmful to both the user and the environment and require costly waste disposal procedures. We developed safer methods to replace both stains using McCormick Schilling red food color. Eggs, juveniles, and adults of Meloidogyne incognita stained in roots with red food color were equally as visible as those stained with acid fuchsin. Egg masses stained with red food color appeared as bright-red spheres on the root surfaces and were highly visible even without magnification. Replacement of acid fuchsin and phloxine B with red food color for staining nematodes is safer for the user and the environment, and eliminates costly waste disposal of used stain solutions.