2004 Vol. 25, No. 5

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研究论文
China is often known for bestriding Palaearctic and Oriental biogeographic realm,but the precise division east of Qinling Mountain is not specific all the while.By using the data of amphibians distributed in 14 zoogeographical provinces in Henan,Anhui and Jiangsu (2 orders,10 families,17 genera,and 42 species),the similarity of species indicates that the division in those districts appears to be a transition zone:its northern border is along Qinling Mountain-Funiu Mountain-Huaihe river-the chief irrigation canal of North Jiangsu;its southern border is along Funiu Mountain-Tongbai-Dabie Mountain-foothill of South Huaihe-canal of Tong-Yang.The even accurate division in this area depends on the research of more taxa of animals,and on the large scale of deep scout.
The gonadotropin (GTH) secretion from pituitary fragments of helmet catfish (Cranoglanis bouderius) was studied by a perfusion incubation system and GTH radiommunoassay (RIA).The results showed that chronic administration of gonadotropin hormone-releasing hormone analogs (GnRH-A) was able to stimulate GTH release from pituitary fragments in vitro,which was consistent to African catfish (Clarias gariepinus) and catfish (Silurus asotus).The insensitivity to chronic administration of GnRH-A was not be observed in the helmet catfish,which was consistent to catfish and African catfish,but different from that in goldfish (Carassius auratus) and Cyprinus carpio haematopters.Repetitive pulse administration of GnRH-A was also able to stimulate GTH release from the pituitary fragments in dose-dependent manner in helmet catfish.These results showed that chronic administration of GnRH-A could have an effect on artificial propagation of helmet catfish.
Nucleotide sequences of segments of the mitochondrial control regions were analyzed to infer the phylogenetic relationships among 7 macaques.High nucleotide diversity in Macaca assamensis and relatively low diversity in M.thibetana were found.Based on the ML tree from control regions,species in our study can roughly be sorted into three species groups except for the phylogenetic position of M.fascicularis,I.e.,silenus group,including M.leonina;sinica group,including M.arctoides,M.assamensis,and M.thibetana;and fascicularis group,including M.mulatta and M.cyclopis.A discrepancy between earlier studies (Fooden & Lanyon,1989;Tosi et al,2003a;Deinard & Smith,2001;Evans et al,1999;Hayasaka et al,1996;Morales & Melnick,1998),our result supported the hypothesis that M.fascicularis diverged earlier than M.leonina.Mitochondrial paraphyly in eastern M.mulatta (with respect to M.cyclopis) and eastern M.assamensis (with respect to M.thibetana) were clearly observed in our study.In accordance with the results of Y chromosome,allozyme,nuclear genes and some morphological data (Delson,1980;Fooden & Lanyon,1989;Fooden,1990;Tosi et al,2000,2003a,b;Deinard & Smith,2001),our study on control region sequences supported M.arctoides to be classified into the sinica group.However,this result disagreed with the previous mtDNA studies (Hayasaka et al,1996;Morales & Melnick,1998;Tosi et al,2003a).
Polychlorinated biphenyls (PCBs) are widespread environmental contaminants that are possible health hazards for human beings through a variety of pathways.In the present study,50 time mated pregnant rats were divided into five groups and injected daily from gestational days 7 to 18 with either 2,2,4,4-tetrachlorobiphenyl (PCB 47) or 3,3,4,4-tetrachlorobiphenyl (PCB 77) or seseme oil (control) to evaluate the effects of these PCBs on prenatal and postnatal development.Offspring were examined for malformations of genitalia at birth and in adulthood.Body weight gains of these animals were checked every 7 days through postnatal day (PND) 119.There were no clinical signs of toxicity in the PCB-treated dams or their offspring throughout the experiment.Litter size and sex ratio of the litters were not affected.Both PCBs produced a significant increase in the females anogenital distance,suggesting a modification of androgen responsiveness in females resulting from PCB exposure during development.Similar effects were not seen with the males.The proportion of individuals with eyes open by PND 15 was significantly reduced by both PCBs.Exposure to 1 mg/kg body weight of PCB 77 significantly reduced body weight gains in male pups from PND 35 to 119.However,no significant differences were found in body weight gains of the pups exposed to PCB 47.
This paper dealt with the nucleotide composition and the phylogenetic relationship among 8 species in Pentatomidae (Pentatominae,Asopinae,Tessaratominae,Scutellerinae) based on 432 bp sequences of Cyt b gene.The results showed:the average contents of T,C,A and G are 31.3%,12.4%,37.6% and 18.7%,respectively;the contents of A+T (68.9%) is obviously higher than that of C+G (30.1%),and come up to 82.7% at the third position of codon.The divergence of sequences is higher among genera and species,and replacement of nucleotides mostly occurs at the third position.The bug,Megacopta cribraria regarded as outgroup,the phylogenetic tree is set based on molecular information.Altogether with morphology characters,it is very reasonable that the two subfamily,Tessaratominae and Scutellerinae should be separated from family Pentatomidae,and be two valid families.The phylogenetic relationship of them is shown as follow:Tessaratomidae and Scutelleridae constitute a sister group and diverge more early than Pentatonidae;as a monophyletic clade,Pentatomidae is the most evolutionary group in Pentatomoidea.
Habitat selection of red deer (Cervus elaphus alxaicus) was studied from November to December,2003 in Helan Mountain which geographically locates in 38°21′-39°22′N,105°44′-106°42′E.Fourteen ecological factors of 87 sites used by red deer and 50 random plots were measured by locating from fresh sign or dung during 25 transects surveys crossing the whole study area.These factors included vegetation types,dominant tree,slope direction,slope location,food abundance,tree density,shrub density,slope degree,altitude,snow depth,distance to water resource,distance to human disturbance,distance to bare rock,and hiding cover.Red deer preferred montane grassland and montane conifer forest,and avoided subalpine shrubland and meadow;selected for mixture habitats,but rejection of habitats dominated by Juniperus rigida,Pinus tabulaeformis and no tree;utilized the paces with slopes exposed to the sun for lower slopes,and avoided shady slopes,upper and middle slopes.Comparing usage sites and random plots,usage sites were characterized by higher shrub density,higher food abundance,lower slope gradient,shallower snow cover and approach to water resource.Most sites were located farther away from bare rock and human disturbance.Results of principal component analysis showed that the 6 principal components explained 84.89% of the total variance.The first principal component was positively related to vegetation type,tree density,shrub density,slope direction,slope degree,distance to water resource,snow depth,and altitude.
We studied the thermal dependence of food assimilation in two juvenile skinks,Sphenomorphus indicus (snout-vent length:42.8-54.4 mm,n=12) and Eumeces elegans (snout-vent length:43.9-57.3 mm,n=10),from a population in Chuzhou,Anhui,eastern China.The temperature of experiments was set 24,26,28,30 and 32℃,respectively.Food passage time,daily food intake,apparent digestive coefficient (ADC),assimilation efficiency (AE) and body-mass change of two skinks were affected by temperature.The food passage time decreased with increase in temperature within the range from 24 to 30℃ and then nearly leveled at higher temperatures in two juvenile skinks.Daily food intake,bodymass change of juvenile S.indicus were lower at 30 and 32℃ than those from 24 to 28℃,ADC and AE decreased with increase in temperature within the range from 24 to 30℃ and increased at 32℃.Daily food intake of juvenile E.elegans increased from 24 to 26℃,and decreased at temperatures higher than 26℃.ADC and AE were higher in body temperature within the range from 24 to 28℃ than those at 30 and 32℃.Bodymass change was apparently greater at 26℃ than at other lower or higher temperatures.Our data indicate that the food assimilation of the juvenile S.indicus and E.elegans are lower than the adults.
A pair of degenerate primers were used to amplify polymorphic segments of the second exon of MHC class Ⅱ B genes from the genomic DNA of Alligator sinensis.Sequences were obtained from cloning,single strand conformation polymorphism analysis and sequencing.By comparing with another eight species MHC sequences,differences from sequences and variable sites were confirmed.Phylogenetic relationships were constructed by neighbor-joining method in MEGA and maximum parsimony method in PAUP4.0.Ten different nucleotide sequences were obtained,which were 166 bp long (except one 160 bp).There are 38 variable sites among ten nucleotide sequences and 23 variable sites among amino acid sequences.The number of nonsynonymous (dN) substitutions of pABS was higher than that of synonymous (dS) substitutions.The ten nucleotide sequences can be clustered into two clades (group A and B) in NJ and MP phylogenetic trees.Some specific sites were found between the two groups,including 9 nucleotide sites and 7 amino acid sites.The high polymorphism of MHC class Ⅱ B genes in A.sinensis was of great benefit to genetic conservation in the captive population of A.sinensis.
By means of non-ionic detergent extraction and scanning electron microscopy,it was shown that the cortical cytoskeleton is a three-dimension network composed of non-ciliaed-regional skeleton,ciliature skeleton and skeleton-associated fibers in Euplotes gracilis.All kinds of the skeleton are made up of the fibers forming fiber net,layer,band,sheet and other structural units.The non-ciliaed cortical skeleton is composed of the surface fiber net and the sub-pellicular fiber layer located in the cortical periphery.The ciliature skeletons,I.e.adoral zone of membranelles skeleton,paroral membrane skeleton and frontal-ventral-transverse cirri skeleton,are located in the cortex according to their corticotype and form an elementary part of the ventral cytoskeleton.Although these skeletons manifested different appearances,they possessed identical structure,namely a functional unit formed by the kinetosomes,ciliature bracket and skeleton-associated fibers.It was supposed that the fiber net forming the regional structures on the cell surface might play a role in connection of the surface parts and in the interaction between the cell and its environment.In ciliature cytoskeleton,the kinetosomal complex might play a role of microtubule-organizing center in the formation of ciliature bracket and skeleton-associated fibers and etc.
We studied the ultrastructure of epididymal spermatozoa of Eumeces elegans.After epididymal tissues of E.elegans were double fixed with 2.5% glutaric dialdehyde and 1% osmic acid,the ultrathin section were observed under H-600 transmission electron microscopy.The spermatozoa contain two major components,a head and a tail.The head contains an acrosomal complex and a nucleus,and the tail a neck,a midpiece,a principal piece and an endpiece.The mature spermatozoa are characterized by:a depressed acrosome at the anterior portion;an acrosomal vescile divided into cortex and medulla;a subacrosomal cone filled with paracrystalline subacrosomal material;a pointed prenuclear perforatorium;a stopper-like perforatorium base plate;an elongated nucleus;an epinuclear lucent zone;rounded nuclear shoulders;a coned nuclear fossa;a bilateral stratified laminar structure within neck region;absence of a endonuclear canal;a long axis of the proximal centriole almost vertical to that of the distal centriole;nine peripheral dense fibres connecting inward with the corresponding 9 triplets of the distal centriole,and backward with the doublets of the axoneme;central fibres connecting with the two central singlets;a short midpiece;columnar mitochondria with linear cristae;each intermitochondrial ring structure consisting of the complete ring of small regularly ovoid or small trapezoid dense bodies;a fibrous sheath into the midpiece;an annulus closely attached to the inner surface of the plasma membrane;the arrangement pattern of the ring structure and mitochondria in rs1/mi1,rs2/mi2,rs3/mi3,and rs4/mi4;mitochondria in order of 10 in transverse section;a thin zone of cytoplasm at the anterior portion of the principal piece;the enlarged fiber 3 and fiber 8 disappearing at the anterior portion of the principal piece;the axoneme complex having an usual 9+2 pattern.The sperm ultrastructure of E.elegans is similar to that of the species within the Sphenomorphus and the Egernia groups,but evidence of spermatozoal autapomorphies is not found in E.elegans.
The presence investigation and morphology observation of 5-HT endocrine cells in the digestive tract of Calotes versicolor were done with the anti-5-HT serum by the method of the ABC immunohistochemical technique.The results indicate that 5-HT cells distribute throughout the digestive tract,and the density curve of 5-HT cells appears "M".The distributive density of 5-HT cells is the maximum in jejunum,the second in stomach and the minimum in esophagus.The shapes of 5-HT endocrine cells are diverse,such as round,ellipse,shuttle,tapering and so on.The cells are mainly round and ellipse in the stomach,pyloric part of stomach and rectum,while the cells are mainly tapering in the small intestine and the tapering cells always have one long processus extending to either the gut lumen or lamina propria.The 5-HT cells are found between gastrointestinal epithelial cells,at the basal region of epithelial cells,between glandular epithelial cells and in the lamina propria.The majority of 5-HT endocrine cells perform endocrine function and the minority has exocrine function.It indicated that the distribution of 5-HT cells may be related to the feeding habit of Calotes versicolor by analysing and contrasting.
For further understanding the digestive physiology of white Ibis,by employment of ABC (streptavidin-peroxidase) immunohistochemical method we studied the distribution of endocrine cells containing 5-hydroxytryptamine (5-HT),met-enkephalin (ENK),substance P (SP),motin and gastric inhibiting polypeptide (GIP) in the gastrointestinal tract of white Ibis (Threskiornis melanocephalus).The results were as follows:5-HT immunoreactive cells were located throughout the gastrointestinal tract with the highest density in the cecum.However,these immunoreactive cells were nearly absent from the stomach.The cells containing ENK and SP were located in the intestine,but they were far sparser than 5-HT cells.Either ENK or SP cells were not congregated throughout the gastrointestinal tract.The cells immunoreactive to motin and GIP were not observed in the gastrointestinal tract of white Ibis.The analysis suggests that the distribution above endocrine cells in the gastrointestinal tract of white Ibis resembles in other bird species,but differs in other vertebrates.
To investigate the effects of dietary vitamin C polyphosphate on anti-heat stress ability in mice,the 48 male mice of 3-4 weeks old with an initial body weight of 16-29 g were divided into four groups [one control group ? and three experimented groups (Ⅰ,Ⅱ and Ⅲ)],which were fed with 35% vitamin C polyphosphate supplementation at the dosages of 0,500,2 500 and 5 000 mg/kg diets,respectively.After feeding 4 weeks,half of mice per group were killed,the other halves of the mice were treated with 35±1℃ for 24 h.Their livers were collected,and the levels of lipid peroxides (LPO) and activity of the superoxide dismutases (SOD) were determined with thiobarbituric acid reaction and nitrite-form method,respectively;and the activities of catalase (CAT) and glutathione peroxidase (GSH-Px) with colorimetry method.The results showed:liver LPO levels in heat stressed C and Ⅰ significantly increased,while Ⅱ and Ⅲ had no significant changes compared with non-heat stressed those.The activities of SOD and GSH-Px in stressed C significantly decreased,while the other three groups had no significant difference compared with non-heat stressed those.The activities of SOD in Ⅱ and Ⅲ were significantly higher than those of C and Ⅰ,and the activity of GSH-Px in Ⅲ was higher than those of the other three groups in stressed mice.The activity of CAT in stressed C and Ⅰ notably reduced,but Ⅱ and Ⅲ had no significant changes compared with non-stressed those.In stressed mice,the activities of CAT in Ⅱ and Ⅲ were higher than those of both C and Ⅰ.These results suggested that heat stress increased liver LPO level and depressed antioxidase activity in mice,while vitamin C polyphosphate alleviated the adverse effects caused by heat stress.
X-ray microanalysis was used to study the elemental composition of the shell of the freshwater testate amoeba Difflugia tuberspinifera Hu et al.,1997 collected from Mulan Lake,Hubei province,China in July 2003.The results show that the shell is composed of ten elements:Si in greater quantity;then Ca and Al;and traces of K,Na,Cl,Fe,Mg,S and P.The analysis of results suggests that D.tuberspinifera in elemental composition appears to occupy a middle position between marine and soil testate amoebae.
Nested polymerase chain reaction (PCR) and standard PCR amplification of the Wolbachia surface protein (wsp) gene were used to assay the infection of the population of Liposcelis tricolor by endosymbiotic Wolbachia.The sensitivity of standard PCR was compared with that of nested PCR in monitoring Wolbachia in L.tricolor by using the universial primers of wsp gene and the primers of A and B subgroup.About 610 bp region of Wolbachia wsp gene,500 bp region of Wolbachia A subgroup wsp gene and 450 bp region of Wolbachia B subgroup wsp gene were sequenced from this host population.The result suggested that this tested population of L.tricolor was infected by two strains of Wolbachia and nested PCR possessed a higher sensitivity.
The migratory locust,Locusta migratoria,occurs in two extreme phases,solitarious and gregarious,with intermediate forms in between.Solitarious and gregarious individuals look so different in morphological,physiological,behavioral traits,and body-color that they had been regarded as two different species until Uvarov (1921) formulated the phase polymorphism theory.In this locust,the juvenile hormone is responsible for the induction of green color in solitary hoppers.In recent studies,a dark-color inducing neuropeptide,[His[7]]-corazonin,was isolated and identified from the corpora cardiaca (CC) of locusts through a convenient bioassay using an albino mutant of L.migratoria.Albinism in this mutant is controlled by a single recessive Mendelian unit and it is caused by an absence of [His[7]]-corazonin from the brain and the CC.Injection of [His[7]]-corazonin into nymphs caused them to develop various non-green colors,such as fawn,brown,reddish-brown,black (solitarious body-color) and black patterns with an orange background color (gregarious body-color).Injection of [His[7]]-corazonin into isolated-reared nymphs caused a shift in morphometrics towards values typical for gregarious insects.Those studies provide strong evidences for an important role of [His[7]]-corazonin in the control of phase polymorphism in L.migratoria.
Antimicrobial peptides are distributed in animals and plants,and acted as the first defensive line against microorganisms.Compared with mammals,the acquired immune system in amphibians is very fragile.The innate system is mainly composed of antimicrobial peptides in amphibian skins that act as very important defensive function against the invasiveness of microorganisms including bacteria,fungi,virus and protozoa.A mini-review about the structure,function and application of amphibian antimicrobial peptides is reported in this paper.