Melatonin in the seasonal response of the aphid Acyrthosiphon pisum

Aphids display life cycles largely determined by the photoperiod.During the warm long-day seasons.most aphid species reproduce by viviparous parthenogenesis.The shortening of the photoperiod in autumn induces a switch to sexual reproduction.Males and sexual females mate to produce overwintering resistant eggs.In addition to this full life cycle(holocycle),there are anholocyelic lineages that do not respond to changes in photoperiod and reproduce continuously by parthenogenesis.The molecular or hormonal events that trigger the scasonal response(i.c,induction of the sexual phenotypes)are still unknown.Although circadian synthesis of melatonin is known to play a key role in vertebrate photoperiodism,the involvement of the circadian clock and/or of the hor-mone melatonin in insect seasonal responses is not so well established.Here we show that melatonin levels in the aphid Acyrthosiphon pisum are significantly higher in holocyclice aphids reared under short days than under long days,while no differences were found between anholoeyelic aphids under the same conditions.We also found that melatonin is localized in the aphid suboesophageal ganglion(SOG)and in the thoracic ganglionic mass(TGM).In analogy to vertcbrates,insect-type arylalkxylamine N-acetyltransferases(i-AANATs)are thought to play a key role in melatonin synthesis.We measured the expression of four I-AANAT genes identified in A.pisum and localized two of them in situ in the insect central nervous systems(CNS).Levels of expression of these genes were compatible with the quantities of melatonin observed.Moreover,like melatonin,expression of these genes was found in the SOG and the TGM.     

Different Effects of Homocysteine and Oxidized Low Density Lipoprotein on Methylation Status in the Promoter Region of the Estrogen Receptor α Gene

We investigated the effects of homocysteine (Hcy) and oxidized low density lipoprotein (ox-LDL) on DNA methylation in the promoter region of the estrogen receptor α (ERos) gene,and its potentialmechanism in the pathogenesis of atherosclerosis.Cultured smooth muscle cells (SMCs) of humans weretreated by Hcy and ox-LDL with different concentrations for different periods of time.The DNA methylationstatus was assayed by nested methylation-specific polymerase chain reaction,the lipids that accumulated inthe SMCs and foam cell formations were examined with Oil red O staining.The proliferation of SMCs wasassayed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method.The results showedthat ox-LDL in moderate concentrations (10-40 mg/L) induced de novo methylation in the promoter regionof the ERα gene of SMCs.However,high concentrations (50 mg/L) of ox-LDL,resulted in demethylation ofERα.The Hcy treatment resulted in de novo methylation in the promoter region of the ERα gene with aconcentration- and treating time-dependent manner,and a dose-dependent promoting effect on SMCproliferation.These data indicated that the two risk factors for atherosclerosis had the function of inducingde novo methylation in the promoter region of the ERα gene of SMCs. However,high concentrations (50rag/L) of ox-LDL induced demethylation,indicating that different risk factors of atherosclerosis with differentpotency might cause different aberrant methylation patterns in the promoter region of the ERα gene.Theatherogenic mechanism of Hcy might involve the hypermethylation of the ERα gene,leading to the proliferationof SMCs in atherosclerotic lesions.     

Histochemical study of the pre—and postnatal development of acetylcholinesterase in the rat spinal cord

The distribution of acetylcholinesterase(AChE)-positive structures in the developing rat spinal cord was studied with AChE-histochemistry.AChE-positive perikarya were first seen on embryonic day 14(E14) in the ventrolateral portion of the spinal cord.From that time onward.AChE=containing cells appeared gradually in the intermediate gray,dorsal horn and lateral spinal nucleus of the spinal cord in a ventral-to-dorsal,and lateral-to-medial order.No obvious rostral-to-caudal sequence was found.At birth,the distribution pattern of AChE-positive perikarya was basically similar to that in adults.After birth a dramatic increase in the AChE staining intensity extended from postnatal day 5(P5) to postnatal day 21(P21),In addition,two phases of transient AChE staining were observed in the external surface of the dorsal horn from embryonic day 15(E15) to embryonic day 21(E21) and in the marginal layer from embryonic day 21(E21) to postnatal day 14(P14),respectively.     

Life Science:Innovation and prosperity—commemorating the 60~(th) anniversary of the Chinese Academy of Sciences

<正>In tandem with the birth and growth of the People's Republic of China (PRC),the Chinese Academy of Sciences (CAS) passed through six decades by the year of 2009.     

Construction of normal human IgE phage antibody library and the screening of the anti—trichosanthin IgE

Allergen specific IgE response is the major cause of immediate hypersensitivity.However the number of IgEproducing B cells and the amount of IgE,especially the specific IgE,are so low,it greatly impedes the study of the allergic-specifc antibody responses.Here we report the construction of a normal human IgE combinatorial library.The repertoire of IgE VH genes and of κ genes were separately amplified from normal human peripheral blood lymphocytes through RT-PCR,and were then constructed to form the phage surface display human Fab(IgEVH) library.A plant protein allergen,trichosanthin(TCS),was used to affinity-enrich and to screen the anti-TCS phage HuFab clones from the library.Human IgE(Fab) to TCS were detected.     

Importance of functional classification in the use of carabids for the environmental risk assessment of the GE crops and other agricultural practices

Carabids(Coleoptera:Carabidae)seem to be suitable bioindicalors of the environmental impacts of novel agrotechnologies,including deployment of the genetically engineered(GE)crops.In this article,we describe our effort to employ carabids in the environmental risk assessment(ERA).GE maize MON88017,its near-isogenic hybrid nontreated or treated with the soil insccticide chlorpyrifos,and two reference hybrids were used to compare three different ways how to utilize carabids in ERA.The analysis of abundance of all captured carabids or of the most abundant carabid specics did not disclose any differences between the treatments.The analysis based on the categories of functional traits revealed distinct fecatures of some treatments and proved suitable for ERA because it permitted field data transportability in spite of different species compositions.Our results indicate that GE maize has no detrimental environmental effecl,On the other hand,we found significant trends toward lower abundance and lower species number(including analysis of all carabid species together)in plots treated with the insecticide,and some tendencies to higher abundance and higher species number in plots sown with the reference hybrid PR38N86.Using functional group indicators alows identification of unintended changes in ecological functions of agroecosystem and comparability across geographics.We recommend data evaluation at the level of the categories of functional traits in ERA of GE crops and other agricultural practices.     

Survival strategies of some species of the phytoplankton community in the Barra Bonita Reservoir (São Paulo,Brazil)

The dynamics of the phytoplankton community in the Barra Bonita Reservoir (S?o Paulo, Brazil) were studied through daily sampling in the field (integrated samples from the euphotic zone) and microcosm experiments, for two short periods: the winter of 1993 (June 30 to July 10) and the summer of 1994 (January 24 to February 2). The goal of the study was to evaluate and compare the variations in the composition of isolated phytoplankton community which occur over short periods of time. Three series were separated into Erlenmeyer flasks for each study period, with samples from the euphotic zone divided into three portions: total, smaller than 64 μm, and smaller than 20 μm. All of the Erlenmeyer flasks were inclubated in situ at the sampling station. The maximum period of incubation was 10 d. Variations of the community in the euphotic zone were characterised by high diversity and a community in a state of non-equilibrium in winter, without the predominance of any species. In the summer, the community presented a low diversity and a state of equilibrium, with the predominance of Microcystis aeruginosa. The microcosm experiments showed that the confinement of the community in the Erlenmeyer flasks, and therefore in isolation from the physical variability of the ecosystem, especially in relation to the mixing patterns, stimulated the return of the community to the initial phases of succession with the predominance of small species and those which grow rapidly (r-selective or C-strategist). This revised version was published online in July 2006 with corrections to the Cover Date.     

Down Regulated Expression of the β1 Subunit of the Big-conductance Ca^2＋ Sensitive K＋ Channel in Sphincter of Oddi Cells from Rabbits Fed with a High Cholesterol Diet

Hypercholesterolemia,which is closely related to gallbladder bile stasis,can cause sphincter ofOddi dysfunction (SOD) by increasing the tension of sphincter of Oddi (SO).Intracellular calcium ionconcentration ([Ca~(2 )]_i) could influence the tension of SO.The β1 subunit of the big-conductance Ca~(2 )sensitive K~ channel (BK_(Ca) can enhance the sensitivity of the BK_(Ca) channel to [Ca~(2 )]_i.Absence and decline ofthe BK_(Ca) channel subunit β1 could lead to many diseases.However,the relationship betweenhypercholesterolemia and the expression of β1 subunit is not well understood.In this study,we successfullyexpressed and purified the rabbit BK_(Ca) β1 subunit protein and prepared its polyclonal antibody.The specificityof the prepared antibody was determined by western blotting.A SOD rabbit model induced by a high cholesteroldiet was established and the expression of the β1 subunit of SO was determined by immunohistochemicalstaining and western blotting.Compared with the controls,our results demonstrated that hypercholesterolemiacould decrease the expression of the β1 subunit in the SO cells from rabbits.This indicates that lowerexpression of BK_(Ca) channel β1 subunit might induce SOD.     

CO2 flux dynamics and its limiting factors in the alpine shrub-meadow and steppe-meadow on the Qinghai-Xizang Plateau北大核心CSCD

Aims Alpine shrub-meadows and steppe-meadows are the two dominant vegetation types on the Qinghai-Xizang Plateau, and plays an important role in regional carbon cycling. However, little is known about the temporal- spatial patterns and drivers of CO2 fluxes in these two ecosystem types. Methods Based on five years of consecutive eddy covariance measurements (2004-2008) in an eastern alpine shrub-meadow at Haibei and a hinterland alpine steppe-meadow at Damxung, we investigated the seasonal and annual variation of net ecosystem productivity (NEP) and its components, i.e. gross primary productivity (GPP) and ecosystem respiration (Re). Important findings The CO2 fluxes (NEP, GPP and Re) were larger in the shrub-meadow than in the steppe-meadow during the study period. The shrub-meadow functioned as a carbon sink through the five years, with the mean annual NEP of 70 g C·m-2·a-1. However, the steppe-meadow acted as a carbon neutral, with mean annual NEP of -5 g C·m-2·a-1. The CO2 fluxes of steppe-meadow exhibited large variability due to the inter-Annual and seasonal variations in precipitation, ranging from a carbon sink (54 g C·m-2·a-1) in 2008 to a carbon source (-88 g C·m-2·a-1) in 2006. The differences in carbon budget between the two alpine ecosystems were firstly attributed to the discrepancy of normalized difference vegetation index (NDVI) because NDVI was the direct factor regulating the seasonal and inter-Annual NEP. Secondly, the shrub-meadow had higher carbon use efficiency (CUE), which was substantially determined by annual precipitation (PPT) and NDVI. Our results also indicated that the environmental drivers of CO2 fluxes were also different between these two alpine ecosystems. The structure equation model analyses showed that air temperature (Ta) determined the seasonal variations of CO2 fluxes in the shrub-meadow, with NEP and GPP being positively correlated with Ta. By contrast, the seasonal CO22 fluxes in the steppe-meadow were primarily co-regulated by soil water content (SWC) and Ta, and increased with the increase of SWC and Ta. In addition, the changes of Re during the growing season in two ecosystems were directly affected by GPP and soil temperature at 5 cm depth (Ts), while Re during non-growing season were determined by Ts. These results demonstrate that the synergy of soil water and temperature played crucial roles in determining NEP and GPP of the two alpine meadows on the Qinghai-Xizang Plateau. © 2018 Editorial Office of Chinese Journal of Plant Ecology. All rights reserved.     

Effect of ConA—receptor interaction on the structure of cell membrane

Recently,the effect of ligand receptor interaction on the membrane structure of liposomes has been studied extensively,However,little is known about how it exists on biological membranes,In this paper,the effect of Concanavalin A(ConA) receptorinteratcion on the structure of cell membranes was studied by Circular DIchrosim(CD) and 31P Nuclear Magnetic Resonance(NMR).CD results of both the purified macrophage membranes and human erythrocyte hgosts(EG) showed that the conformation of membrane proteins changed after ConA binding.For further research,31P-NMR was used to detect the orgainzation of phosp[holipid molecules on macrophage membranes.After ConA binding,the tendercy to form non bilayer structure increased with the amount of ConA.The changes of 31P-NMR spectra of living macrophages might be partly due to the above stated reason too.In addition,ConA-receptor interaction also induced similar results of 31P-NMR spectra in EG.In contrast,wheat germ agglutinin (WGA),another kind of lectin,rarely showed the same influence.     

Where Is the Site of the “Oxygen Burst” Located During Light Induction in Dark-Adapted Leaves？ A Study Using Photoacoustic Techniques

The “oxygen burst” phenomenon that appeared during the light-induction period of intact leaves could be monitored using a photoacoustic technique high time resolution. The relationship between oxygen bursts and dark-adapted time, far-red light pretreatment, photothermal signal, and chlorophyll a (Ch1 a) fluorescence kinetics were investigated in the present study. Using extraneous inhibitors or cofactors of electron transport, a modified vacuum-infiltration method was undertaken to locate directly the site at which oxygen bursts of intact leaves occurred. We found that the photothermal signal showed little evidence of oscillation during the light-induction period. The oxygen burst was resolved into two components if darkadapted time lasted longer than 20 min. Methyl viologen (MV) or far-red light could not eliminate the first component, whereas formate-Na (pH 7.0, 20μmol/L) eliminated the first component but had no effect on the second one. Furthermore, the photochemical quenching, the electron transport rate of Chl a fluorescence,and the first component of the oxygen bursts approached lowest values simultaneously. This evidence indicates that the site at which the first component of oxygen bursts occurred was located between photosystem (PS)I and PSII (i.e. the PQ pool). The formate-Na experiment also showed a linkage between the first component and the S state of oxygen evolution at the donor side of PSII. Furthermore, elimination of the second component by far-red light and absorption of the second component by MV indicated that the site at which the second component of oxygen bursts may be located at the acceptor side of PSII.     

Does the Genetic Code Have A Eukaryotic Origin?

In the RNA world, RNA is assumed to be the dominant macromolecule performing most, if not all, core "house-keeping" functions. The ribo-cell hypothesis suggests that the genetic code and the translation machinery may both be born of the RNA world, and the introduction of DNA to ribo-cells may take over the informational role of RNA gradually, such as a mature set of genetic code and mechanism enabling stable inheritance of sequence and its variation. In this context, we modeled the genetic code in two content variables-GC and purine contents-of protein-coding sequences and measured the purine content sensitivities for each codon when the sensitivity (% usage) is plotted as a function of GC content variation. The analysis leads to a new pattern-the symmetric pattern-where the sensitivity of purine content variation shows diagonally symmetry in the codon table more significantly in the two GC content invariable quarters in addition to the two existing patterns where the table is divided into either four GC content sensitivity quarters or two amino acid diversity halves. The most insensitive codon sets are GUN (valine) and CAN (CAR for asparagine and CAY for aspartic acid) and the most biased amino acid is valine (always over-estimated) followed by alanine (always under-estimated). The unique position of valine and its codons suggests its key roles in the final recruitment of the complete codon set of the canonical table. The distinct choice may only be attributable to sequence signatures or signals of splice sites for spliceosomal introns shared by all extant eukaryotes.     

Use of Whole-Exome Sequencing for the Diagnosis of Atypical Birte-Hogge-Dubé Syndrome

正Destruction of the lung parenchyma may result in the formation of cysts,cavities and bullae.Definition of the type of destructive lesion is best achieved by high-resolution computed tomography(HRCT)scans of the chest(TrotmanDickenson,2014).The loss of lung parenchyma may result     

Effect of Zn（Ⅱ） on the Structure and Biological Activity of Natural β-NGF

Only β-NGF, the subunit of the 7S NGF complex, exhibits NGF activity, but the function ofthe zinc ion in native β-NGF has received little attention. Flameless atomic absorption spectroscopy (FAAS)measurements reveal that native β-NGF contains Zn(Ⅱ) with a Zn(Ⅱ)/β-NGF stoichiometry of 1 : 14.6.The presence of Zn(Ⅱ) in the native molecule results in significant changes of the secondary structure andlocal tertiary structure around Trp(s) with respect to those of apo β-NGF, as suggested by spectra offluorescence and circular dichrosim. Stopped-flow studies show that there are at least two steps during theinteraction of Zn(Ⅱ) with the apo form. In comparison with its apo form, the native β-NGF shows a higherability to trigger the proliferation of TF1 cells and mediate the survival of PC 12. Thus it is most likely that thestructural changes caused by the presence of Zn(II) directly lead to the increase in the biological activity of β-NGE All results indicate that Zn(Ⅱ) in native β-NGF plays an important role in the structure and thebiological activity of the protein.     

Herpesviruses and the Type Ⅲ Interferon System

Type Ⅲ interferons (IFNs) represent the most recently discovered group of IFNs.Together with type Ⅰ IFNs (e.g.IFN-α/β),type Ⅲ IFNs (IFN-λ) are produced as part of the innate immune response to virus infection,and elicit an anti-viral state by inducing expression of interferon stimulated genes (ISGs).It was initially thought that type Ⅰ IFNs and type Ⅲ IFNs perform largely redundant functions.However,it has become evident that type Ⅲ IFNs particularly play a major role in antiviral protection of mucosal epithelial barriers,thereby serving an important role in the first-line defense against virus infection and invasion at contact areas with the outside world,versus the generally more broad,potent and systemic antiviral effects of type Ⅰ IFNs.Herpesviruseses are large DNA viruses,which enter their host via mucosal surfaces and establish lifelong,latent infections.Despite the importance of mucosal epithelial cells in the pathogenesis of herpesviruses,our current knowledge on the interaction of herpesviruses with type Ⅲ IFN is limited and largely restricted to studies on the alphaherpesvirus herpes simplex virus (HSV).This review summarizes the current understanding about the role of IFN-λ in the immune response against herpesvirus infections.     

Studies on DNA—protein interactions in the upstream regulatory region of the human ε—globin gene promoter

The erythroid- and developmental stage-specific expression of the human ε-globin gene is controlled,in part,by the 5‘-flanking DNA sequence of this gene.In the present study,we have used DNA-protein binding assays to identify trans-acting factors which regulate the temporal expression of the human ε-globin gene during development.Using gel mobility shift assays and DNaseI footprinting assays,a nuclear protein factor (termed ε-SSF1) in the nuclear extracts from mouse haematopoietic tissues at d 11 and d 13 of gestation was identified.It could specifically bind to the positive control region (between-535 and -453bp) of the human ε-globin gene.We speculated that the ε-SSF1 might be an erythroid-and developmental stage-specific activator.In addition,we found another nuclear protein factor (terned ε-R1) in the nuclear extract from mouse fetal liver at d18 of gestation,which could strongly bind to the silencer region (between-392 and -177bp) of this gene.Therefore,we speculated that the ε-R1 might be an erythroid-and developmental stagespecific repressor.Our data suggest that both ε-SSF1 and ε-R1 might play important roles in developmental regulation of the human ε-globin gene expression during the early embryonic life.On the hand,we observed that the binding patterns of nuclear proteins from three cell lines (K562,HEL and Raji) to these regulatory regions were partially different.These results suggest that different trans-acting factors in K562,HEL and Raji cells might be responsible for activating or silencing the human ε-globin gene in three different cell lines.     

Establishment of the diploid gynogenetic hybrid clonal line of red crucian carp × common carp

This study investigated the gynogenetic cytobiological behavior of the third gynogenetic generation (G3), which was generated from the diploid eggs produced by the second gynogenetic generation (G2) of red crucian carp × common carp, and determined the chromosomal numbers of G3, G2×scatter scale carp and G2×allotetraploid hybrids of red crucian carp × common carp. The results showed that the diploid eggs of G2 with 100 chromosomes, activated by UV-irradiated sperm from scatter scale carp and without the treatment for doubling the chromosomes, could develop into G3 with 100 chromosomes. Similar to the first and second gynogenetic generations (G1 and G2), G3 was also diploid (2n=100) and presented the hybrid traits. The triploids (3n=150) and tetraploids (4n=200) were produced by crossing G2 with scatter scale carp and crossing G2 with allotetraploids, respectively. The extrusion of the second polar body in the eggs of G2 ruled out the possibility that the retention of the second polar body led to the formation of the diploid eggs. In addition, we discussed the mechanism of the formation of the diploid eggs generated by G2. The establishment of the diploid gynogenesis clonal line (G1, G2 and G3) provided the evidence that the diploid eggs were able to develop into a new diploid hybrid clonal line by gynogenesis. By producing the diploid eggs as a unique reproductive way, the diploid gyno- genetic progeny of allotetraploid hybrids of red crucian carp × common carp had important signifi- cances in both biological evolution and production application.     

Substitutions of the Conserved Gly47 Affect the CF1 Inhibitor and Proton Gate Functions of the Chloroplast ATP Synthase ε Subunit

The conserved residue Gly47 of the chloroplast ATP synthase ε subunit was substituted with Leu, Arg, Ala and Glu by site-directed mutagenesis. This process generated the mutants εG47L, εG47R, εG47A and εG47E, respectively. All the ε variants showed lower inhibitory effects on the soluble CF1(-ε) Ca^2 -ATPase compared with wild-type ε. In reduced conditions, εG47E and εG47R had a lower inhibitory effect on the oxidized CF1(-ε) Ca^2 -ATPase compared with wild-type ε. In contrast, εG47L and εG47Aincreased the Ca^2 -ATPase activity of soluble oxidized CF1(-ε). The replacement of Gly47 significantly impaired the interaction between the subunit ε and γ in an in vitro binding assay. Further study showed that all ε variants were more effective in blocking proton leakage from the thylakoid membranes. This enhanced ATP synthesis of the chloroplast and restored ATP synthesis activity of the reconstituted membranes to a level that was more efficient than that achieved by wild-type ε. These results indicate that the conserved Gly47 residue of the ε subunit is very important for maintaining the structure and function of the ε subunitand may affect the interaction between the ε subunit, β subunit of CF1 and subunit Ⅲ of CF0, therebyregulating the ATP hydrolysis and synthesis, as well as the proton translocation role of the subunit Ⅲ of CF0.     

Val 70,Phe 72 and the last seven amino acid residues of C—terminal are essential to the function of norepinephrine transporter

The norepinephrine transporter(NET) is a member of the Na^ /Cl^- dependent neurotransmitter transporter family and constitutes the target of several clinically important antidepressants.To delineate the critical amino acid residues and the function of C-terminal in regulating transport activity of NET,here we constructed two site mutants (V70F,F72V;V70I,F72V) and one C-terminal truncated mutant (Δ 611-617).The wild type and mutants of NET were expressed in Xenopus oocytes by injection of their cRNA.We found that all of these mutants lost their transport activity.These results indicate that the amino acid residues of V70 and F72,and the last seven amino acids of C-terminal are essential to the transport activity of NET.