留言板

尊敬的读者、作者、审稿人, 关于本刊的投稿、审稿、编辑和出版的任何问题, 您可以本页添加留言。我们将尽快给您答复。谢谢您的支持!

姓名
邮箱
手机号码
标题
留言内容
验证码

2001年  第22卷  第2期

显示方式:
研究论文
The effects of pulsing electromagnetic fields (PEMFs) on cells are very important subjects in the field of bioelectromagnetics.In this experiment,the cytogene tic effects of PEMF on domestic pig lymphocytes were tested in vitro.Pig lymphocytes in RPMI 1640 medium were exposed to PEMFs of 100 kHz and 200 kHz for 12,24 and 48 hours.Chromosomal aberrations (aneuploidy,breaks,gaps,et al) were significantly increased in exposed cultures,and of these aberration s,56% chromosomal or chromatid breaks and 42% gaps induced by PEMFs were the points of pig chromosomal fragile sites.The baseline frequency of sister-chromati d exchange (SCE) increased after exposing lymphocytes continuously to PEMFs of 100 kHz and 200 kHz for 48 hours.These results suggested that the exposure to PEMFs might induce a type of DNA lesion and chromosomal aberrations.
Mitochondrial cytochrome b (cyt-b) genes were sequenced from one individual of N.coucang and two individuals of N.pygmaeus.By comparing with the cyt-b sequences of three species in Lorisidae,the divergence and base substitution among these sequences were analyzed.The phylogenetic tree,in agreement with the fossil and morphologic data,was reconstructed with Daubentonia madagascarie nsis as the outgroupThe base composition of N.coucang and N.pygmaeus showed the same character as that of other mammals.The Tv/Ts ratio between the two Nycticebus species was as 6 times as other pairwise comparisons.The lo w values (<0.1) of Ka/Ks ratio implied a strong selective constraint against th e nonsynonymous sites of the cyt-b genes from the species in Lorisidae.Based on the fossil data,the transitions and synonymous mutations at the third codon position that have shown a linear relation with time,the estimations of 3 Myr (m illion years) and 6 Myr were the divergent time between N.coucang and N.py gmaeus,and between Lorisines and Galagines groups,respectively.
Amicronucleate cell lines of the ciliated protozoan Pseudourostyla cristata from different mating types are generated by microsurgery.With a rescue conjugating amicronucleates with micronucleates,the sexual development of conjugants and exconjugants becomes more normal than that in conjugation among amicronucleat es.The first cortical reorganization proceeds as usual to generate a set of incomplete ciliature,but the membranelle number of adoral zone of membranelles (A ZM) and the number of frontal-ventral-transverse cirri (FVT) approach those in conjugation among micronucleates,and differentiation and positioning of the ciliature appear normally.It is evident that the micronucleus is important for maintaining regular development of the first cortical reorganization.During conju gation,a male gametic nucleus from the micronucleate mate migrates into its amicronucleate partner and a female gametic nucleus stays in situ,the haploid gametic nucleus in both conjugants transforms into a hemizygote without fertilization.After twice post-hemizygote division,a new micronucleus and a macronucl ear anlage are generated as usualThe macronuclear anlage develops through chromosome polytenization,fragmentation,genome rearrangement and DNA-poor stages.However,in most exconjugants,development of the macronuclear anlage becomes arrested before the next stage when a vacuolated and DNA-poor mass forms and then is extruded from the anlage,and thereafter the anlage turns pycnotic.The second ortical reorganization could not be initiated in such cells.But in a few others (about 10% exconjugants) of some specific mating combinations in which the young micronucleate cell line (28 or 46) is micronuclear donor for nucleogenesis,the macronuclear anlage can develop beyond the stage,and the cells can undergo the second,and then the third and the fourth round of cortical reorganization.After the sexual development,the cell transforms into asexual cycle and a viable clone is produced.The correlation between macronuclear anlage development and initiation of the second cortical reorganization suggests that the crucial morphogenetic signal to trigger the second morhpogenesis is provided by the macronuclear anlage which has developed beyond the post-polyteny DNA-poor stage.
The effects of 4-androstene-3,17-dine (ADSD) and 17α-methyl-testosterone (MT) via implantation at intervals of 15 days on maturation of the male silver eel,and their effects on brain and pituitary GnRH levels,pituitary and serum GtH levels were studied.Multiple implantations of ADSD and MT increased the GSI and stimulated gonadal maturation of the male silver eel.After 3 im plantations,the GSI of males treated with MT were significantly higher than that treated with ADSD,whereas after 6 implantations their GSI were not significantly different.The mGnRH contents in the brain and pituitary were significantly increased after 3 and 6 implantations of ADSD and MT,and the mGnRH contents were elevated with increasing times of implantations.The pituitary GtH levels of male eels wer significantly increased by multiple implantations of ADSD and MT,and after 3 implantations the pituitary GtH level of MT-treated male eels was significantl higher than that treated with ADSD.Serum GtH levels of MT-treated male eels were increased significantly after 1[st] implantation,however,serum GtH levels in the male eel treated with ADSD were significantly increased only after 4 implantations.Taken together,these results indicated that ADSD and MT could stimulate gonadal development and had positive feedback effects at the brain and pituitary in the male eel,and the higher potency of MT in the induct ion of gonadal development maybe due to its higher ability to stimulate GtH synt hesis and release in the male eels.
To observe the localization of neurokinin receptor (NK3r) in the mouse gastrointestinal tract.Immunohistochemistry and immunoreactive fluorescence were used in the experiment.Our results showed that there arent NK3r-like (-Li) positive materials on the smooth muscle cells of oesophagus,stomach,and intest ine and other regions muscularis.The nerve cell bodies with immunoreactivity for NK3r mainly distributed in the submucous nerve plexus or myenteric nerve plexus of gastrointestinal tract except oesophagus and stomach and rectum.The reaction production was distributed on the nerve cell surfaces.Occasionally was observed in the cell plasma,but was very weak stained.Immunoreactive nerve cells morphology was mostly like type of Dogiel Ⅱ.This research work not only described the distribution of neuronkinin B receptor in the mouse gut in detail,but also provided a morphological basis for deducing the functional identity of NK3r-immunoreactivity nerve cells in the gut.
Euconocephalus nasutus (Thunberg) and E.pallidus (Redtenbacher) were quite similar in morphology,but their songs and the stridulatory organs were obv iously different.The chirp of the songs of E.nasutus lasts 4.5 ms,consi sting of 4 pulse-strings with an inte-chirp interval of 1.8 ms,and the fre quency of highest power peak is about 11.37 kHz.The chirp of the songs of E.pallidus has only one pulse-string with an inter-chirp interval of 4.3 m sThe pulse-string duration is 1.6 ms and the frequency of highest power peak is about 11.03 kHz.The file of E.nasutus is curved with thin ends and enlarged middle portion.The file of E.pallidus is straight,and slightly widened in the middle portion.
Nesting success of Houbara Bustard (Chlamydotis undulata macqueenii) was stu died in Mulei,Xinjiang from April to June,1998.A total of 16 nests and 25 bro ods were found.A bimodal distribution of laying dates suggested the existence o a replacement clutch.3 to 6 eggs were laid with the fresh weight of (64.7±5 .8)g and the size of 60.9 mm×43.9 mm.The clutch size was (4.1±0.8) for the first clutch cohort and (3.5±0.6) for the second clutch cohort.The nes ting success was 87.5%.The hatchability was 83.6%.Brood size keep the same within broods between hatching and fledging.This suggested that some females wer e very good at bringing their chicks to fledging.
The Ficus racemosa L.(1753) is a keystone plant species in the tropical rai nforest in Xishuangbanna.The fig tree (Ficus racemosa) and figpollination wasp (Ceratosolen sp.) are highly coevolved species that depend completely on mutual benefit for continued reproduction.The main result of this study indi cated that the earlier emerged male wasp cut the exit holes both from the gall and fig fruit for the female,which dont have the ability to cut the exit hole for themselves.In Ficus racemosa pollen tends not to escape from the anthers after dehiscence until the stamens are disturbed by the fig wasp.The females opened the anthers with the antennal scapes,mandible,leg and collected the pollen.The pollen-bored females fly about 5-80 minutes to find the recep tive syconiaAs soon as a pollinating fig wasp reached the interior of the youn g fig fruit to be pollinated,it pushed its head among the stigmas for 4-9 hours ,then oviposited in the short stigmas (gall flowers) of the fig.
Bullacta exarata (Philippi,1848) is a favorite seafood and a tidal and economic seashell with high nutrition and edible value in South China.It can be found in the intertidal flats in China,Japan and Korean along the coasts of West Pacific Ocean B.exarata was one important biological resource which played an mportant role in the food chain of the tidal flat ecosystem as a consumer.Since late 1990s,the population ecology and toxicology of B.exarata had been partly studied along the coasts in Zhejiang,China,however,the spatial distrib ution had never been analyzed.Moreover,B.exarata had never been reported a gain up to now in the Yangtze River Estuary although it was first recorded forma lly in late 1980s B.exarata population in the Nanhui tidal flat and North Chongming Island in the Yangtze River Estuary had been investigated and analyzed by Taylorpower law,Iwaos patch regression and Morisita ind ex from May to June,2000.The results indicated that the B.exarata populati on distributed widely between the supratidal zone and subtidal zone of the inter tidal flats from south Chaoyang Farm to Luchao Port in Nanhui tidal flat and in North Hangzhou Bay,from Niupenggang Port to Puyu Port in North Chongming Island ,in North Changxing Island,Mi-and sub-Kiuduansha shoal in the Yangtze Rive r Estuary.It was shown that the natural B.exarata population distributed extensively with clumped and negative binomial distribution [Morisita index (I)=2.61,P<0.01] theoretically.The regression equations of Taylor power law and Iwaos patch regression were lnS[2]=-0.7472+1.3484 lnx-(r[2]=0.8132,P<0.01,n=8) and m*=-1.005+1.076 6x-(r[2]=0.9936,P<0.01,n=8) respectively.The population densities at 8 sample sites in the Yangtze River Estuary (D7>D6>CPB>DZB>CYN>DZN CNB>CP) were greatly different significantly by the analysis of variance [ANOV AF=42.52>F[0.01(7,32)]=3.26,P<0.01],which were resulted obviously from human activities,including land reclamation of tidal flats and environmental pollution,and different natural conditions between island and tidal flats.
The fitness of 14 common host plants to the leafminer was quantitatively tested with the selective index and modified fitness index methods in Shanxi Province. According to the fitness index (FI),the host plants of Liriomyza sativae were divided into three categories by the hierachical clustering analysis:the mos suitable,suitable and secondary.On the basis of those,the relationship of the fitness of host plants to the leafminer with the surface and anatomical structure of leaf blades were further studied in this paper.The results indicat ed that there were no significant correlated relationship (r<[r0.05]) between FI and the epicuticle hair numbers,its hair length,epicuticle thickness,palisade tissue thickness and thickness of leaf blades respectively,whereas there existed significant correlated relationship (r=0.6236>r[0.05]) between the mine area of L.sativae on the host plants and the cell width of palisade tissue of leaf blades.These results might provide a theoretical basis for the sustainable control of L.sativae.
This paper describes three new species and a new rec ord of the genus Anatkina Young from China.The type s pecimens are deposited in Guizhou University. 1 Anatkina wufengana Yang et Du,sp.nov.(Fig.1) Length(incl.teg.):♂ 9.1 mm. This species has unique red stripes pattern on pronotum and forewing,the shape of aedeagus is also different from that of any other species of the genus. Holotype ♂,Hubei Province:Wufeng county,1999-07-10,coll.DU Yan-Li. The specific name refers to the type locality. 2 Anatkina zhoui Yang et Li,sp.nov.(Fig.2) Length(incl.teg.):♂ 15.2 mm. This species is closely related to Anatkina igriventris Li,but its pronotu m with two black spots and a cross black stripe instead of six black spots;scut ellum with two basal black maculae mixed at base;the shape of male pygofer proc ess,subgenital plate and aedeagus also distinctly different from the latter. Holotype♂,Guangxi Province:Daqing Mt.,1986-05-22,coll.ZHOU Zhi-Hong. The specific name is a patronym in honor of the collector. 3 Anatkina jianfengana Yang et Li,sp.nov.(Fig.3) Length(incl.teg.):♂ 12.8 mm. This species resembles Anatkina incurvata Kuoh,but can be distinguished fro m the latter by its crown with basal macula bigger leading to cover the oculi;s cutellum without distal black spot;forewing with spots smaller and a distinct L -shape black stripe at end;male pygofer process smooth and extending posterior ly not to pygofer apex;the shape of subgenital plate,aedeagus and style also o bviously different. Holotype♂,Hainan Province:Jianfengling,1997-05-15,coll.WANG Lian-Min.The specific name refers to the type locality.4 Anatkina assamensis (Distant),1880 (Fig.4)Tettigonia assamensis Distant,1880:203 Tettigoniella assamensis (Distant):Distant,1908:207 Bothrogonia assamensis (Distant):Metcalf,1965:234 Anatkina assamensis (Distant):Young,1986:46 New record to China.Materials examined:3♂♂,2♀♀,Yunnan Province:Pianma area,2000-08-16,coll.LI Zi-Zhong,YANG Mao-Fa and CHEN Xiang-Sheng.Distribution:India (Assam);China (Yunnan).
The paper consists of three parts:1) the discipline structure—population energ etics and ecological energetics;2) development history and the present status in China;3) the scope of population energetics.The third part emphasizes estima ting the energy demands of a population involving integrating individual energy demands with information on population size,structure,and dynamics.It include s individual metabolism,energetic equivalence of different activities,breeding energy and daily energy expenditure (DEE) and so on.
Recent progress in study about the effect of stress on aquatic animals growth,behavior and physiological activity was summarized in this paper.It is shown that stress significantly inhibited growth,behavior,humour immunity,cell immunity and endocrine function in aquatic animal.This paper will provide in formation on the reaction of aquatic animal to various stressors,and help to understand the progress and trends in this field.
Total RNA was separated from the abdomen of house fly,after which had been challenged for 24 hours with E.coli and Staphylococcus aureus.Then,the mR NA was purified from it.After that,ds-cDNA was synthesized by reverse transcriptase from mRNA,and small cDNA which was lower than 400 bp was removed by Sep harose CL-4B spun column.After EocRⅠ/NotⅠAdaptors were added to cDNA,those that werent ligated to cDNA were removed by another Sepharose CL-4B spun column.ThecDNA was inserted into λgtll,the recombined vector packaged in vitro,infected a host strain Y1090.Thus,the cDNA library was co structed.The titer of the newly constructed cDNA library was 3.46×10[5] pfu/mL,and its recombination rate was 99.6%.The library would provide basis for t he cloning of the antimicrobial peptide genes of house fly.
The concentration of serum antibody of the softshelled turtle was measured using SRID.The concentrations of non-immune serum and immune serum antibodies wer e about 9.623 mg/mL and 17.097 mg/mL respectively.The later was about two folds as much as the former.This showed that the level of serum antibody of turtle would increase quickly and keep higher level when it is stimulated with antigen.
From Australia to Asia (China),the main species of the migratory bird are the waders and terns.In Oct.1999,an invitation was extended by Dr.Clive Minton of the chairman of the Victorian Wader Study Group (VWSG) to catch and band waders and terns at Sandy Point,Swan Bay,Swan Island,Anderson Inlet/Inverloch,Phil lip Island,Mud Islands,Geelong and Werribee and so on.The paper summarizes the methods (catch,bio-metric data,banding,recoveries,flagging,satellite tra cking,data analysis on computer,fox control et al.) and results (species of wader and tern,number of banding from 1975 to 1999,calculate the minimum age ,breeding success,age of first breeding,levels of fat deposits,molt,the distance of moved) and discuss.The total 141787 waders,about 35 species (from 1975 to 1999) and 6057 chicks and adults of terns,about 7-9 species (1998-1999) were captured and banded by the Victorian Wader Study Group.