Effects of 5-Azacytidine(AZA)on the Growth,Antioxidant Activities and Germination of Pellicle Cysts of Scrippsiella acuminata(Dinophyceae)

In this study,we investigated the effects of different concentrations of 5-azacytidine(AZA),a DNA methyltransferase in-hibitor,on the growth,antioxidant activities and germination of pellicle cysts of Scrippsiella acuminata.The purpose of this study is to understand the toxic effects of AZA on marine microalgae,and to demonstrate the effect of DNA methyltransferase inhibitors on the germination of pellicle cysts.Results showed that AZA inhibited the growth of S.acuminata significantly,and displaced a clear dose-dependent inhibition trend with the 96h EC50 of 146.77μmolL^(-1)(35.84mgL^(-1)).Pellicle cysts of S.acuminata were less sensitive to AZA than the vegetative cells,and the EC50 value of AZA to the germination of pellicle cysts of S.acuminata was 8.08mmolL^(-1)(1.97g L^(-1)).After exposed to AZA,the antioxidant activities in S.acuminata responded rapidly and significantly.Among them,soluble pro-tein and superoxide dismutase(SOD)were more sensitive to AZA,and significant promotions occurred after exposed to 10μmolL^(-1)AZA for 24h.Meanwhile,malondialdehyde(MDA)contents in algal cells did not change significantly after exposed to low concen-trations of AZA,but increased firstly and then decreased under high concentration of AZA.The glutathione(GSH)levels in S.acu-minata increased significantly under high concentrations of AZA,and remained unchanged at low concentrations of AZA.The results suggested that the enhanced protein level and SOD activity of S.acuminata eliminated reactive oxygen species(ROS)to a certain ex-tent,and thus protected algal cells against damages of ROS caused by AZA.

A TEM study on pre-excystment cellular structures of Euplotes encysticus

Right before the excystment of an Euplotes encysti-cus sawtooth-like folds appeared among the pellicle plas- malemma, the inner and outer alveolar membranes were still sticking together, and were not distinguishable. Mi- crotubular layers already formed at the sites beneath the dorsal cortical pellicle corresponding to vegetative cells,but they still proceed to be organized on the ventral struc-tures. Cristae, highly-tangled with tubular-type struc-tures, appeared on the mitochondria, and were morpho-logically similar to that of vegetative cells. In the cor-tical ciliatures, such as ciliary shafts, kinetosomes, sur-rounding fibrillar cirral baskets, and attached structures of ciliatures, etc., they are different from those in rest- ing cysts which are degenerated or lost. All the cilia- ture microtubules of ciliary shafts are of the 9+2 pattern,but the microtubule-like structure aggregates at triplet - microtubule centers of many kinetosmes, are still under various stages of differentiation. Microtubules beneath the kinetosomal rows are of a developmentally elongated stage; crowded chromatins of various shapes and sizes are found in macronucleus, but there are no nuclear pores (formed by nuclear membrane as in resting cysts) on the nuclear membrane where these chromatins attached.

Two new glucosides from the pellicle of the walnut (Juglans regia)

A newα-tetralonyl glucoside,6'-O-acetyl-juglanoside E(1),and a new dihydrophaseic acid glucoside,dihydrophaseic acid 1-O-(6-O-acetyl)-glucopyranoside(2),together with two known ones,juglanoside E(3)and dihydrophaseic acid(4),were isolated from the pellicle of the walnut(Juglans regia).The structures of the new compounds were elucidated by comprehensive spectroscopic analysis,including IR,HRESIMS,1D and 2D NMR data.

Human chromosome pellicle antibody recognizing centromere protein-C(CENP-C),the main component of the kinetochore

Recently the antichromosome antisera from several scleroderma patients have been found to recognize the pellicle of metaphase and anaphase chromosomes. In order to identify the pellicle components, we used these antichromosome antisera to screen a human embryonic cDNA library. The sequences of the positive clones are identical to the cDNA gene sequence of CENP-C (centromere protein C), a human centromere autoantigen. This result suggusts that CENP-C is a component of the pellicle of human metaphase and anaphase chromosomes.

Assembly and disassembly of mammalian chromosome pellicle

By means of indirect double immunofluorescent staining, the coordination of PI antigen and perichromonucleolin (PCN), the constituent of nuclear periphery and nucleolus respectively, in the assembly and disassembly of chromosome pellicle during mitosis was studied. It was found that in 3T3 cells, during mitosis PI antigen began to coat the condensing chromosome .surface earlier.than PCN did. However, both of them completed their coating on chromosome at approximately the same stage of mitosis, prometaphase metaphase. The dissociation of PI antigen from chromosome pellicle to participate the formation of nuclear periphery took, place also ahead of that of PCN. At early telophase PI antigen had been extensively involved in the formation of nuclear periphery, while PCN remained in association with the surface of decondensing chromosomes. At late telophase, when PI antigen was localized in an fairly well formed nuclear periphery, PCN was in a stage of forming prenucleolar bodies.

Genesis of Low-Resistivity Oil layers from Cretaceous System in Luxi Area and Its Geological Significance

Genesis of low resistivity oil layers from cretaceous system in Luxi area was studied. The result shows that the resistivity of oil layers is lower than that of water layers from Tugulu Group(K 1tg),Cretaceous in Luliang area,Zhungeer basin, resulting in a disaccordance with logging interpretation on oil layers,oil water layers and water layers?The research on the petro texture of reservoirs also shows that the watered clay pellicle (I/S, I, ch) is well developed in K 1tg expands the section of conductive net and results in a low resistivity of oil layers.