2005 Vol. 26, No. 3

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Although noncoding regions play an important role in gene expression and regulation,it is difficult to detect natural selection at this level. Recently,some studies use the ratio (ω) between the nucleotide substitution rate in the detected regions and the nucleotide substitution rate in neutral regions as an indicator to detect natural selection in noncoding regions. However,to the noncoding regions,its more informative to identify those nucleotide sites under positive selection. We developed a new maximum likelihood method to detect natural selection at the nucleotide site level and to identify those nucleotide sites that may contribute to functional divergence. This method can be applied to both coding regions and noncoding regions. Appling this method to previous reported genes that subjected to positive selection shows that this method is efficient to detect natural selection on nucleotide sites both in coding regions and noncoding regions.
In this study,the social ranks of male root vole siblings (Microtus oeconomus) were determined by dyadic interaction test,and then their behavioral patterns to orders of fresh urine from familiar and novel male voles were investigated in a behavioral choice maze. The behavioral statistics showed that: ① The urine marks can be used as the standard to estimate social rank when two voles in dyadic interaction. ②Subordinates preferred familiar odors. They spent more time visiting and approached more frequently to familiar odors than strange ones. And they self-groomed much more in familiar odorant box than in strange one. ③Dominants preferred strange odors, and showed significant differences between the familiar odors and the strange odors in visit time, sniff/lick frequency and time, self-grooming, and countermarks. ④There existed a significant difference in behavioral pattern of response to strange odors between the dominant and subordinate voles. The results indicate that different response patterns of male voles in different social ranks reflect the different territorial behavioral patterns.
Three fusion peptides,PZα1,PZα2 and PZα1Zα2 for Zα1 domain,Zα2 domain,and Zα1Zα2 domains of Carassius auratus PKR-like gene,respectively,were successfully expressed by a prokaryotic expression system and then purified by affinity chromatography. Gel mobility shift assay revealed that PZα1Zα2 rather than PZα1,PZα2,and mixture of PZα1 and PZα2,was capable to bind to polyinosinic∶polycytidylic acid (Poly I∶C) in vitro. In addition,all of the three fusion peptides all could form dimer,with strong dimerization for PZα2 and PZα1Zα2 but a relative weak one for PZα1. The results suggest that dsRNA, the by-product generated during virus replication in host cells,probably binds to the Zα domain of CaPKR-like and then regulates its physiological function.
The efficacy of ethanol extracts from four plants,Dennettia tripetala Baker,Eugenia aromatica Baillon,Piper guineense Thonn et Schum and Anchomanes difformis P. Beauv. As bioinsecticides for control of adult Sitophilus zeamais Motschulsky,Tribolium castaneum Herbst,Callosobruchus maculatus Fabricius,Oryzaephilus mercator Fauvel and Lasioderma serricorne Fabricius were determined at two concentrations (0.5% and 2.0%) in the laboratory. All extracts were toxic to beetles with E. aromatica being the most potent of four plant materials tested and had the least LT50 value. This was followed by A. difformis extract. At 2.0% v/w extract concentration, percentage grain damage by insects in treated grains stored for 90 days was nil. Grains protected with A. difformis had the least percentage seed germination of 62.50% while those protected with P. guineense had the highest percentage germination (74.58%) at 2.0% extract concentration. The mean percentage germination in the control was 72.72%. Treatment of grains with plant extracts had no significant (P>0.05) effect on its water absorption capacity.
For utilization of the mouse embryonic stem (ES) cells for various purposes,it is desirable that the cell lines are established from various sources such as inbred and outbred mouse strains. So far,however,most ES cell lines used in genetic manipulation have been derived from the 129/Sv strain. In this paper,we have established ES cell lines from blastocysts of the CD-1,C57BL/6J and 129/Sv×C57BL/6J mice besides 129/Sv mouse with a fibroblast cell as feeder cells,and supplemented with 1,000 unit/mL LIF in the culture medium. Twelve ES cell lines were obtained from CD-1,129/Sv, C57BL/6J and 129/Sv×C57BL/6J mouse blastocysts. No ES cell line from KM embryos suggests that KM strain might have inhibitory genetic factor(s) for the ES cell formation. Some ES cell lines could be obtained from hybrids at high efficiency suggested a heterosis effect can be expected for establishing ES cell lines in mice. These ES cell lines produced chimeric mice and contributed to the germ-line. The results indicate that genetic background is an important factor in isolating ES cells.
We used tiger frogs (Hoplobatrachus rugulosus) collected from Lishui (Zhejiang,eastern China) to study sexual dimorphism in morphological traits and food habits. Females larger than 80 mm SUL (snout-urostyle length) and males larger than 70 mm SUL were considered to be adults,and others to be juveniles. The frog is sexually dimorphic,with females being the larger sex. Juveniles were not sexually dimorphic in any of the examined morphological traits. Head length and hind-limb length were larger in adult females than in adult males and fore-limb length,eye diameter and tympanum diameter were larger in adult males than in adult females,when influence of variation in body size (SUL) was removed using ANCOVAs. Other examined morphological traits did not differ between adult females and adult males. The magnitude of hind-limb length deviating from the bilateral symmetry did not differ between adults and juveniles and between both sexes,whereas the magnitudes of fore-limb length deviating from the bilateral symmetry were greater in adults than in juveniles and were greater in females than in males. A principal component analysis resolved three components (with eigenvalues ?1) from ten size (SUL) free morphological variables, accounting for 64.6% of variation in the original data. The first component (26.9% variance explained) had high positive loading for size-free values of head width,eye diameter and tympanum diameter,the second component (19.7%) for size-free value of hind-limb length,and the third component (18.0%) for size-free values of interocular length and internasal length. Adult females had lower scores on the first axis of a principal component analysis than did adult males,but the score on the second and the third axes did not differ significantly between adult females and adult males. The tiger frog is an insectivorous species,but it also feeds on invertebrates other than insects. Frogs of different ages and sexes,in various degrees,differed in food niche width and breadth. However,no direct evidence shows a noticeable contribution of the divergence in head size to the segregation of food niche between males and females,which is considered to important to mitigate the competition for food between both sexes.
Habitat selection of Rana kukunoris,Nanorana pleskei and Bufo minshanicus was studied in Zoige Wetland National Nature Reserve,Sichuan Province,southewest of China,from August to September,2004. Twelve ecological factors of 16 sites used by the 3 amphibian species were selected and measured. These factors included grazing condition (GC),herbage height (HH),herbage cover (HC),number of yak dejectas (YJ),number of Ochotona cavities (OC),number of sokhor mounds (SM),ground temperature (GT) and moisture (GM),soil temperature (ST),distance to small waterbodies (DSW),distance to large waterbodies (DLW) and distance to roads (DR). The results indicated that R. kukunoris,N. pleskei and B. minshanicus all preferred habitats characterized by distance near small waterbodies (such as ponds) (≤100 m),distance farther (>1 000 m)to larger waterbodies (eg. Rivers and lakes),moderate grazing intensity,absence of OC. By comparison,it was found that R. kukunoris and N. pleskei significantly selected summer pasture habitats characterized by HH 5.1-10.0 cm,DSW 0-50 m,significantly not to select habitats with too many SMs (>10). R. kukunoris significantly selected habitats with DR>50 m;B. minshanicus had no significant selection for GC and DR but significantly selected habitats characterized by HH>20.0 cm,DSW 51-100 m and did not select habitats without SMs,N. pleskei significantly selected habitats with DR 0-50 m. The 3 amphibians differed in the habitat selection to some extent,which suggested they had special requirement for habatits respectively and GC,HH,GM,ST,SM,DLW,DSW and DR were the critical factors distinguishing habitat selection of the 3 amphibians species by stepwise discriminant analysis.
From October to November 2004 by using a sampling method,we investigated the soil macrofauna communities at 7 using types of soils,paddy field (P),kaleyard (K),orchard (O),wilderness (W),yard (Y),lawn (L) and building site (B) in Jinhua,Zhejiang. There were 1 161 soil macrofauna individuals belonged to 20 orders,8 classes,and 3 phylums in total samplings. The dominant orders were Nematoda and Hymenoptera,the frequent orders were Araneae,Diplura, Lumbricida,Isopoda,Stylommatophora,Coleoptera,Lepidoptera and Diptera,and then the remnant orders were rare orders. The complexity index of community ? tended O>K>W>B>L>P>Y,and Shannon-Weiner index (H′) L>B>W>K>O>P>Y. C was manifested better than H′ in representing the complexity and the diversity of communities. The vertical distribution of soil macrofauna had obvious surface assembly. Using the Hierarchical Cluster and the Non-matric Multi-dimensional Scaling method,the 7 communities were classed to 3 groups: highly disturbing and non-bestrow group,herbage growth group and orchard group,which shows the response of soil macrofauna communities to the different soil using types.
In order to evaluate indoor environment and animal welfare in the housing of sheep,it is necessary to establish a quantified behavioral data of sheep as feedback. Individual behaviors of the Chinese little fat-tailed sheep in three growth phases (lambs,pregnant and lactating ewes) were observed and recorded on a sheep farm in Inner Mongolia in summer,2003. Data processing showed:(1) Behavioral patterns in duration from observed samples (9 in each group) were made up of: time spent in eating and drinking 29.18%,in rumination 28.37%,in resting 31.51%,in locomotion 10.21%,and in others 0.71% including environmental investigation,being alarmed or startled,and social interaction. Individually behavioral durations of three growth phases showed significant difference in durations with respect to intake and drinking,rumination,resting,and locomotion respectively (Kruskal-Wallis H tests,P<0.001). (2) Results of posture choice of the sheep in different growth phases show that time spent in lying for rumination or resting was significantly more than time spent standing by lambs,pregnant and lactating ewes respectively (Wilcoxon test,P<0.001). (3) The counts data of animal behaviors in three levels of temperature showed that on average 31.3% of individuals were lying for rumination and resting at 21-23 ℃,75% at 25-27 ℃,97.13% at 29-31 ℃ in houses of pregnant ewes. This is a significant effect of temperature on number of pregnant ewes lying on floor of the houses (Friedman test,P<0.05). (4) Our data of counts of the pregnant ewes selecting space in lying on floor in the houses from 12:00 to 17:00 at temperature ranging 27-31 ℃,showed that there was significant differences in individuals selecting between A-zone (places naturally ventilated well and without sun shining) and B-zone (places exposed to the sun) (McNemar test,P<0.0001). Many of the ewes increasing from 66% to 83% selected A-zone,whereas a few of the other ewes decreasing from 31% to 14% selected B-zone during observed period. Our results indicate that the behavioral patterns of sheep in the loose housing systems react to the physiological needs at different growing phases,and to environmental impact factors such as temperature and housing space. The study suggests that to establish a quantitative index profile of the sheep behaviors for a feedback review tool may be helpful to enhance the design of production processes and building layout and environment for loose housing systems.
In order to understand the ecophysiological characteristics of the waxwing (Bombycilla garrulous) and black-faced bunting (Emberiza spodocephala) inhabiting in relative cold area,we measured their metabolic rates (MR),body temperatures (Tb),and thermal conductance ? at temperature range of 5,10,15,16,18,20,22,25,26,28 and 30 ℃. Adult waxwings and buntings were live-trapped by mist net in the Qiqihar City,Heihongjiang Province (47°29′N,124°02′E) from April to July 2004. Eight waxwings (seven males and one female) and eight buntings (all males) were used in this experiment. Body masses to the nearest 0.1 g were determined immediately upon capture with a Sartorius balance (model BT25S). The mean body mass of waxwings and buntings were 64.9±0.6 g and 15.1±0.2 g (mean±SE),respectively. Birds were transported to the laboratory and caged (50×30×20 cm3) under natural photoperiod and temperature. Food and water were supplied ad lib. MR was measured by using closed circuit respirometer,and temperature was controlled by water bath (±0.5 ℃),Tb was measured by insertion of a digital thermometer (Beijing Normal University Instruments Co.) into the cloaca,and C was calculated at each temperature below the thermal neutral zone using the formula:C=MR/(Tb-Ta),where Ta is ambient temperature. The thermal neutral zone of waxwings and buntings were 18-27 ℃ and 20-26 ℃,respectively. The mean metabolic rates within thermal neutral zone of these species were 2.33±0.47 and 4.75±0.18 mL O.2/(g·h),respectively,which are 110% and 151% of the expected value from their body mass,respectively. Mean Tbs of waxwings and buntings were 38.20±0.05 and 38.25±0.05 ℃,respectively. Conductances of waxwings and buntings were 0.13±0.00 and 0.26±0.00 mL O.2/(g·h·℃),respectively,representing 153% and 157% of the expected value based on their body mass. Below the lower critical temperatures MR increased with declining Ta and the regression equations relating MR to Ta was described as:MR=5.46(±0.19)-0.17(±0.01) Ta for waxwings and MR=9.54(±0.52)-0.23(±0.03) Ta for black-faced buntings,respectively. The ecophysiological characteristics of these species are: high body temperature and metabolic rate,wide thermal neutral zone and lower critical temperature and relatively high thermal conductance. These properties might make them acclimatized to their environments and survive at relative cold areas for these species.
In this study,the genetic relationships among five species belonging to four genera of Mermithidae were detected using RAPD. Twelve primers were screened from 47 random primers and amplified 161 bands (from 200 bp to 3 200 bp). 150 (93.17%) of these bands were polymorphic bands. The number of obtaining segments of individual primer was between 11-16,the average was 13.42. Neis similarity coefficients and genetic distance were calculated using the RAPDistance and MEGA softwares. The phylogenetic trees were constructed with the methods of UPGMA and NJ. The results from two methods of cluster analysis were similar in general,and the relationship indicated the five species of Mermithidae could be distinguished with RAPD markers and were grouped into two distinct clusters. In the phylogenetic trees,Romanomermis culicivorax and R. wuchangensis (all parasite in larvae of mosquitoes) grouped together,then they grouped with Agamermis changshaensis (parasite in Homoptera) into one cluster. Ovomermis sinensis (parasite in Lepidopters) grouped with Amphimermis sp. (parasite in Homoptera) into one cluster. The genetic distances of five Mermithidae species showed that the relationships of intra-genus were nearer than that of inter-genus,the genetic distance between R. culicivorax and R. wuchangensis was 0.1789,but the genetic distance between inter-genus were 0.4471-0.5488. All those results suggested that RAPD was suitable for analysis of phylogenetic relationship among species of Mermithidae.
seven biscuit types namely, Okin,Digestive,Cabin,Peanut,Cream crackers,Hobnobs and Glucose and wheat flour were screened for their resistance to Tribolium castaneum (Herbst) at ambient temperature of 28±2 ℃ and 78±2% relative humidity in the laboratory. 50 g of each biscuit sample were infested with four female and two male adult beetles and left for 15 days then remove for a resistant experiment and 70 days for a mortality experiment. Each treatment and the control without beetles were replicated three times. Results showed that there was significant difference (P<0.05) in the mortality rate of T. castaneum in the biscuit types and wheat flour samples,while there was no significant difference (P>0.05) in the weight loss of biscuit types. The highest adult mortality of beetles (100%) was obtained from Peanut biscuits at 28 days after infestation while there was only 5.5% adult mortality in wheat flour at 70 days after infestation. The susceptibility index was 0 for all the biscuit types since there was no adult emergence indicating that they were resistant to T. castaneum infestation. Resistance in the biscuit types could be due to chemical additives (e.g. sodium chloride and sodium bicarbonate) used in the production of biscuits, which may have inhibitory effect on the development of T. castaneum and also the low moisture content of the biscuits. Packages that can easily be perforated or damaged to allow absorption of moisture from the environment should not be used in packing biscuits.
Effects of five TEST extenders varying in osmolality on rhesus monkey sperm cryopreservation were studied,using TTE as the control. These five extenders were designated as TEST,mTEST1,mTEST2,mTEST3 and mTEST4,and the corresponding osmolalities were 688,389,329,166 and 43 mOsm/kg,respectively. Semen were diluted in one step into freezing media containing glycerol,and the final concentration of glycerol was 5%(v/v). Sperm survival was determined by assessment of sperm motility and membrane integrity prior to and after cryopreservation. Membrane integrity was evaluated using Hoechst 33342/propidium iodide dual staining procedure and flow cytometry. The results showed that,before freezing,motility and membrane integrity of spermatozoa diluted in TEST and mTEST4 were drastically reduced (P<0.001) compared with fresh sperm. In remaining groups,sperm function remained unaffected after equilibration except that the membrane integrity of spermatozoa diluted in mTEST2 was significantly lower than that of fresh semen (P<0.05). The sperm cryopreservation efficiency for these extenders,evaluated by post-thaw sperm motility and membrane integrity,is: TTE,mTEST3 and mTEST1> mTEST2> TEST and mTEST4 (P<0.05). The results suggest that isosmotic,moderately hyperosmotic or hypoosmotic extenders are favorable for the cryopreservation of rhesus monkey spermatozoa and the hyperosmotic stress of TEST accounts for the lower survival of rhesus monkey spermatozoa frozen in this medium.
The multivariate variance analysis,cluster analysis and principal component analysis (PCA) were conducted based on 18 morphological characters that including 8 numerical characters and 10 metric characters in amphioxus populations from Qinhuangdao (QHD),Qingdao (QD) and Xiamen (XM) with 25 samples,respectively. The results showed that significant difference (P<0.05) in means of 18 morphological characters such as length of body,height of body,number of dorsal/ventral septa etc.,existed among 3 different amphioxus populations,and there were great variance among populations than within population. Multiple comparisons of the LSD of morphological characters of 3 amphioxus populations showed that QHD and QD populations existed significant difference (P<0.05) in 14 morphological characters,expected in number of buccal cirri,number of dorsal septa,number of ventral septa and number of total myotomes. QD and XM populations were no significant difference (P>0.05) in 7 morphological characters such as length of body,height of body,number of myotomes in middle,number of gonads,height of rostral fin,height of dorsal fin and height of supra-caudal fin. QHD and XM populations were similar (P>0.05) in 5 morphological characters,e.g. height of ventral fin,length and height of supra-caudal fin,length and height of sub-caudal fin. In the results of cluster analysis suggested that all of the 75 samples were divided into two clusters clearly. ClusterⅡ were mainly maded of 21 samples from XM population, while QHD samples and QD samples were pooled into clusterⅠ. The result of the first three principal components from PCA showed that there were about 3 groups gathered by the all samples,QHD,QD and XM groups. All samples from XM population were pooled into one independent group;QHD and QD groups were pooled with some individual swarmed and crossed each other showed from the graph of PCA. It is inferred that XM geographical population had been great genetic differentiation in morphological characters,and amphioxus populations from QHD and QD also had genetic divergence on the whole while similar in some morphological characters.
Eighteen litters of newborn piglets were divided randomly to control and treatment groups. From 12 days of age,piglets in treatment group were fed starter diet supplemented with 120 mg/kg cysteamine (CS),while the control group were fed basal diet. Piglets were weaned at 35 days of age (D35) in both groups. 6 piglets from each group were slaughtered on D28 (7 d before weaning),D35 (weaning day),D36.5,D38,D42 and D45 (36 h,72 h,7 d and 10 d after weaning),respectively. Radioimmunoassay was applied to determine the serum levels of cortisol,T3,T4 and IL-2. The results indicated that: (1) Cortisol level was stable before weaning in control group,followed by an abrupt increase on D36.5,and was restored to the level of weaning on D42. In treatment group,cortisol level exhibited a tendency of increase from D35 to D36.5,and was restored and stabilized at the level of weaning from D38 onwards. T3 level in control group was higher on D36.5 than that on D28,but there were not significant differences among other age groups. In treatment group,T3 level kept stable throughout the period of investigation. For control,T4 level increased on D36.5 and returned to the weaning day level on D38. T4 level was stable from weaning day to 45 days in treatment group. IL-2 level was kept stable in both groups until D45 when a significant increase was observed. (2) Cortisol level in treatment group decreased markedly by 30% compared with control group on D36.5. CS treatment increased both T3 and T4 levels by 49.2% and 31% on D35, and 38.6% and 45.8% on day 45 (P<0.05),respectively. No significant differences were observed on other ages for T3 and T4,although a tendency of increase was shown in treatment group. IL-2 concentration in treatment group increased by 22.1% (P<0.05),12.6% (P<0.05) and 17.8% (P<0.05) on D36.5,D38 and D45,respectively. The results suggested that cysteamine might help to enhance the resistance of the piglets to weaning stress through increased serum levels of T3,T4 and IL-2,and decreased cortisol secretion during pre- and post-weaning period.
According to age and sex,32 rats and 32 mice were divided into 8 groups. The activities of mATPase of soleus muscle were detected by the mATPase method. Then the percentage of type Ⅰ and Ⅱ fibres were determined. The viscera weight and viscera index were measured and calculated. The result revealed: As far as the proportion of type Ⅱ fibres in soleus was concerned,①the youngs was notably higher than that of the adult in both rat and mouse;the female adults was lower than that of in male adult;②the adult rats was markedly lower than that of in adult mouse. The thymus indexes and the splenic indexes (SI) in young rat and mouse were both markedly higher than that of in adult,whereas the hepatic indexes (HI) were both distinctly lower than that of in adult. The HI and the SI in young and adult rat were prominently lower than those of the corresponding group of mouse. The above results suggested that the activities of mATPase declined during development both in rat and mouse. So the proportion of type Ⅱ fibres gradually decreased. And the activities of mATPase show obvious sex disparities and interspecific diversity.
A novel thrombin inhibitor was identified and purified from salivary glands of ixodid tick,Ixodide sinesis by gel filtration and RP-HPLC. The molecular weight was 6.356 kDa determined by MALDI-TOF mass spectra. It was different from any known serine protease inhibitors identified from ixodid ticks. This inhibitor inhibited thrombin with strong potency,and exhibited no obvious effects on factor Xa and trypsin. The thrombin inhibitor may be used as a candidate to develop vaccine to control ticks.
Like human speech,singing of songbirds is sensorimotor learning by tutor and auditory feedback. The development and crystallization of singing is depended on the integrity of the song system composed of vocal pathway and anterior forebrain pathway. X area in forebrain pathway plays an important role during learning and memory of singing. In this paper,we reviewed studies on the organization and the function in singing development and crystallization,the synaptic plasticity of X area. We also compared learning and memory function of X area to that of mammalian basal ganglia.