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Table of Content

    29 February 2012, Volume 32 Issue 2
    Pericarp thickness and seed size determine acorn dispersal of five rodent-dispersed oak species
    2012, 32(2):  83-89. 
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    Because the seed-eating and-hoarding behaviors of animals are complicated by seed traits,the relationships between seed traits and seed dispersal in animal-dispersed plants are still contentious and need further study. Here,we examined acorn dispersal,both in the field and in enclosure,of five rodent-dispersed oak species (Quercus mongolica, Q. serrata var. brevipetiolata,Q. aliena,Q. variabilis and Q. liaotungensis)with different morphological and chemical traits, to further explore the complex interactions between seed traits and seed dispersal. The results of the field studies showed that acorns with large size and thick pericarp were more likely to be cached than eaten by small rodents, suggesting the importance of seed mass and seed coat thickness in determining seed dispersal at the community level of rodents. Large size and thick pericarp acorns were dispersed further in the field,supporting previous studies that seed dispersal distances are positively correlated with seed mass and seed coat thickness. However, in the enclosures, only pericarp thickness of acorns consistently influenced seed removal,dispersal,and caching by Tamias sibiricus at the population level. Our studies indicate that the effect of seed traits on seed dispersal can be different at population and community levels,and therefore some caution is required in elucidating rodent-mediated seed dispersal measures.
    Population genetic structure and population genetic diversity analysis based on mitochondrial DNA of Asian elephant(Elephas maximus) in China
    2012, 32(2):  90-100. 
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    The Asian elephant (Elephas maximus) is the most endangered probiscidean, and occurs in China only in Yunnan Province. With non-invasive sampling using elephant dung as a DNA source, the population genetic structure and diversity were observed from PCR analysis of 178 individuals. One haplotype (ML&SY&SM&MY1) is shared among 4 conservation areas Mengla (ML), Shangyong (SY), Simao(SM) and Mengyang(MY), including 114 of 178 individuals, which differs from that found in the Nangunhe(NGH) area. Two highly divergent clades, α and β, of Asian elephants in China are observed using phylogenetic analyses and are verified by neighbour-joining(NJ), maximum parsimony(MP) and maximum likehood(ML) approaches. The result showed that the α clade includes 4 populations (ML, SY, SM and MY) and the β calde only includes the Nangunhe population. This also shows that there is high genetic divergence between the Nangunhe population and the other 4 populations. Mitochondrial DNA data analysis showed that genetic diversities in all of the 5 Asian elephant populations are very low, and resulted from habitat fragmentation which separated the effective genetic flow among the 5 populations.
    Genetic diversity of black muntjac (Muntiacus crinifrons)in Jiulongshan National Nature Reserve by feces DNA
    2012, 32(2):  101-109. 
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    Black muntjac (Muntiacus crinifrons)is an important protected animal in China. Recently,the habitat of black muntjac has been seriously damaged and fragmented because of human activities. Thus,it is very important to fully understand the genetic status of black muntjac,providing the scientific foundation on which to develop protective and management
    measures. We collected 61 feces samples,2 muscle samples and 2 skin samples of black muntjac in Jiulongshan National Nature Reserves using non-invasive sampling techniques. Eight specific microsatellite loci were selected for analysis of genetic diversity. The skin and muscle DNA samples served as controls. The results showed that in 61 feces DNA samples, 38 were amplified stably and showed different PCR bands. Thus,we considered the 38 faces samples to be from 38 different individuals. Fifty alleles were detected in 8 microsatellite loci,and the mean number of alleles (A)was 6,ranging from 5 to 8. The effective number of alleles (Ne)between 4.031 and 6.353,with an average of
    5. 297. The expected heterozygosity (He) ranged from 0.763 to 0. 855,with an average of 0.817,and the polymorphism information content (PIC)ranged from 0. 709 to 0. 822,with an average of 0. 775. The average power of discrimination (DP )of 8 loci was 0.931,and the cumulative DP reached to 0.9999. One microsatellite locus (BM1706)very significantly deviated from Hardy-Weinberg equilibrium (P < 0. 01). According to the results,we can see that the black muntjac population in Jiulongshan National Nature Reserves has a high level of genetic diversity.
    Analysis of terrain induced impact on Takin (Budorcas taxicolor)home range estimation:an example from Fixed kernel estimator and Minimum convex polygon
    2012, 32(2):  110-117. 
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    Knowledge of the home range of wildlife is the basis of effective conservation and management. We studied takin (Budorcas taxicolor tibetana)home range in spring with two widely applied methods using GIS related software,where we compared differences between the home range estimates with and without terrain information. All four takin (2♀2♂)were
    fixed with GPS radio collars and the data were obtained in the spring of 2007 and of 2008. The results showed home range size derived with terrain information (FKE95% = 7. 50 ±2. 27,MCP = 7. 01 ± 1.99)was significantly larger than that derived without topographic information (FKE95% = 5. 94 ± 1. 54,t = 3.31,df = 3,P = 0. 045,MCP = 5. 47 ±1. 52,df =
    3,t =3. 34,P = 0. 041). The difference between estimates based on 95% Fixed kernel home range and Minimum convex polygon home range were not significant regardless of including terrain information (t = 0. 612,df = 3,P = 0. 584)or not (t = 0. 718,df = 3,P =0. 524). However,we also found significant differences of home range size between individuals
    (One way ANOVA,df = 3,F = 7. 226,P = 0. 001). The post hoc test between individuals found significant differences between M1 and F1 (P =0. 001),M1 and F2 (P = 0. 031),M1 and M2 (P = 0. 02),F1 and F2(P = 0. 044),whereas no significant difference was detected between M2 and F2 (P = 0. 221),M2 and F1 (P = 0. 598). We also tested the difference of the two methods on the results of spatial overlap between individuals,but no significant difference was detected. Researchers should select appropriate smooth parameters (h)/ bandwidth,because different bandwidth may derive different conclusions of the degree of home range overlap,or even contradictory results.
    Effect of the Wenchuan earthquake on habitat use patterns of the giant panda:a case study of Longxi-Hongkou and Tangjiahe Nature Reserves
    2012, 32(2):  118-123. 
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    The Wenchuan earthquake of May 12,2008 occurred in the Minshan and Qionglai Mountains,where the most important habitats for giant pandas (Ailuropoda melanoleuca)occur.We took advantage of our long-term dataset on panda habitat use in Longxi-Hongkou and Tangjiahe Nature Reserves to investigate pandas′ responses to this disaster. We analyzed the habitat use patterns of giant pandas over the course of a 7 - year period (5 years pre-earthquake and 2 years post-earthquake) along fixed-width line transects. The results showed:(1)Before the earthquake,there were no significant differences in used/ unused frequencies each year for each transect line,in other words,the habitat use patterns of giant pandas were stable before the earthquake.(2)During the 2 years after the earthquake,there were also no significant differences in used/ unused frequencies each year for each transect line. (3)Panda habitat use patterns did not appear to be affected by the earthquake since in the 10 transects surveyed before and after the earthquake,the used/ unused frequencies were not significantly different between the pre - and post-earthquake periods. (4)There was no relationship between giant panda habitat use and landslides in Longxi-Hongkou Nature Reserve. Our findings contribute to ongoing habitat restoration plans and long-term conservation of the giant panda.
    Mammal mortality caused by highways in the Changbai Mountain National Nature Reserve of Jilin Province,China
    2012, 32(2):  124-129. 
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    Mammal mortality and related factors such as traffic volume and vehicle speed,were investigated monthly based on the two main highways in the Changbai Mountain Nature Reserve during three years (2007 - 2009). Our results showed that:(1)there were at least 14 mammal species killed on the highways,representing at least 27% of mammal species occurring in this nature reserve,with three rodent species (Myodes rufocanus,Tamias sibiricus and Apodemus peninsulae )as the main species;(2)the intensity of mammal mortality was 2.57 ± 0.53 individuals/10 km,and the mortality rate of nocturnal mammals accounted for 69. 8% of the total;(3)mammal mortality was highly related to hourly traffic volume and accounts for 69.4% for 1 - 40 vehicles per hour traffic volume,with the highest for 30 - 40 hourly traffic volume;and (4) mammal monthly mortality was highly correlated with traffic volume and vehicle speed each month,with the highest mortality in September.According to the activities and habitats of mammal species,most of these mammals were killed during early morning,at dusk or at night.It is likely that vehicle lighting at night,along with high speed and high traffic volume, may cause large trouble for the animals,and thus lead to high mortality of these animals. Therefore,we suggest that in order to reduce mammal mortality on the highways,it is necessary to control the timing of traffic and reduce traffic volume and vehicle speed in relation to animal activities.
    Early recognition and conditioned place preference for fathers in mandarin vole pups
    2012, 32(2):  130-136. 
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    Early discrimination of the parents by offspring is important for obtaining the maximal level of parental care and resources in colonial species. Mandarin vole (Microtus mandarinus)males exhibit high levels of paternal care. However, it remains unclear whether pre-weaning mandarin vole pups could recognize their father and form conditioned place preference. This was investigated by a series of behavioral tests. It was found that postnatal day (P)14 and P21 pups prefer their fathers over strange males in two-choice tests. Compared to encounters with strange males,P21 pups exhibited lower levels of social investigation and higher levels of following behavior when interacting with fathers. As well,dyads of P21 pup-fathers showed more amicable behaviour than dyads of P21 pup-strange males. However,no significant differences in social investigation or amicable behavior were found for P14 encounters,except for following behavior. In addition,we found that both P17 pups and P23 pups failed to display father induced place preference following 4 consecutive days (P13 - 16 or P19 - 22)of father reinforcing. Taken together,these results indicate that pre-weaning pups can recognize their fathers. Yet,they can not develop a place preference for fathers.
    Morphological characteristics and the first examination of adult neurogenesis of the hippocampus in yak
    2012, 32(2):  137-148. 
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    The morphology and cell types of the hippocampus in adult yak were examined by the traditional staining of H. E and Golgi-Cox,and the neural stem cells and newborn neurons which located in Subgranular zone (SGZ)of the dentate gyrus were observed with Diaminobenzidine (DAB)immunoperoxidase staining and immunofluorescence double-labeling
    for Doublecortin and Neuronal Nuclei (DCX/ NeuN),Glial fibrillary acid protein and Neuronal Nuclei (GFAP/ NeuN). Our data indicate that the yak’s hippcampus mainly contains dentate gyrus and hippocampus proper,and both of them stratify clearly. Granular cells,mossy cells and pyramidal cells are the three major cell types of the hippocampus formation. The soma of pyramidal cells in the CA3 region is much bigger than in the CA1 region,while the latter has an average length of apical dendrites longer than the former. The pyramidal cells contain distinctive sublayers in the CA1 regions,but form a close uniform layer in the CA3 region. The somas of most DCX-positive cells,which distribute individually or in clusters,mainly locate in the deepest part of the granule cell layer closing to the hilus. A layer of GFAP-expressing radial glia-like cells is observed in the subgranular zone of the dentate gyrus,and its cytoplasms and single polarity processes,but not nucleus,are GFAP-positive. A large number of star GFAP-positive cells is scattered throughout the hippocampus. Specially, the densities of GFAP-positive cells in the molecular layer and the boundary of the hilus closing to the granular layer are much higher than those in other zones. The morphological characteristics of the hippocampus in yak is similar to those observed in sheep,but differ from those reported in small mammals,such as rats,mice,cats,and rabbits. Finally,the DCX immunostaining indicates the presence of the newborn neurons in yak’s hippocampus. The immunofluorescence labeling for GFAP also indicates the astrocytes,especially radial glia,in the yak’s hippocamous.
    Rescue of lesser panda canine distemper virus by reverse genetic manipulation
    2012, 32(2):  149-155. 
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    In this study,the CDV originated from lesser pandas was isolated and served as the template for the infectious cDNA clone of CDV. After genome sequencing,seven cDNA fragments containing full-length CDV genome sequence were obtained by RT-PCR. The seven different fragments were digested and spliced together,and then inserted into eukaryotic expression vector pCI. Thus,we obtained the full-length cDNA of CDV lesser panda named pCI-CDV-LP. Furthermore, three helper plasmids were constructed by cloning the N,P,L protein ORF of lesser panda strain CDV in pCI vectors,respectively. The sequences of nuclease and CDV cDNA in pCI vector were verified by restriction enzyme digestion and sequencing. The full-length plasmid and three helper plasmids were then co-transfected into BSR cells using transfection reagent Lipofectamine TM2000. The results of RT-PCR,indirect immunofluorescence assay and viral infection assay showed that the lesser panda CDV was rescued successfully,and the reverse genetics of lesser panda CDV was built successfully. The results of the current investigation provide an important insight into the pathogenesis of canine distemper virus.
    Research advances in Cetacean osmoregulation
    2012, 32(2):  156-167. 
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    As a unique clade of mammalia,Cetaceans complete all of their life activities in water. Cetaceans therefore have developed various strategies to adapt to their aquatic environments morphologically,physiologically and ecologically. Most of the Cetaceans inhabit the hyperosmotic marine environment,but a few species live in the hypoosmotic freshwater systems. However,despite the obvious differences of their living environment,both the freshwater and marine Cetaceans face the same challenge - to maintain the water balance and electrolyte homeostasis of their body. How do Cetaceans adapt to their aquatic environments?What kinds of strategies do they develop in morphology,physiology and ecology?We try to expound upon the osmoregulation process of the Cetaceans in the following aspects:source and metabolism of water/ electrolytes, morphology and histology of the kidney and skin,hormone regulation,and the molecules related to osmoregulation etc. by consulting and discussing the conclusions of previous research in the past century on this issue. Moreover,future research trends and important issues in this area are also discussed and proposed.
    Variation in food habits and digestive tract morphology of the Chinese white-bellied rat (Niviventer confucianus)among different forest types
    2012, 32(2):  168-174. 
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    The morphology and physiological function of the digestive tract, which would be influenced by habitat change and food quality, plays an important role in energy absorption and distribution for animals. To explore the effects of forest alteration on food habits and digestive tract morphology of the Chinese white-bellied rat(Niviventer confucianus), we investigated the variation exhibited, among rats in five different forest habitat types(primary forest, secondary forest, fuel-wood forest, Pinus armandis plantation forest, Larix leptolepis plantation forest). N. confucianus is primarily seminivorous and carnivorous, however we detected no significant variation in dietary biases among rats in the different forest types. In contrast, while stomach mass did not differ among the forest types, freshi weight including caecum and large intestine contents, fresh weight without caecum and large intestine contents, dry weight of the caecum and large intestine did in exhibit variation but with different trends. Dry weight of the small intestine in secondary forest was significantly higher than in other forest types. Length of large intestine in secondary was longer than that in fuel-wood forest, but was similar to chose in other forest types. Similar food habits among different forests correlated to abundant food resources in autumn. The variation in digestive tract morphology is matched to habitat alteration, with benefits for survival, reproduction and recruitment dynamics.
    Variation of urinary reproductive hormones of a captive female African elephant during gestation
    2012, 32(2):  175-178. 
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    In this study we monitored the urinary levels of progesterone (P),estradiol (E2),estriol (E3)and chorionic gonadotropin (CG)of a female African elephant (Loxodonta africana)during pregnancy using radioimmunoassay. It was shown that progesterone levels increased gradually during early pregnancy,peaking at the 4th - 6th month of pregnancy and then dropping to the basal level at delivery. The estriol concentration decreased slowly during gestation,whereas the estradiol level did not change significantly during pregnancy. This is the first report of CG during gestation of African elephant. CG level was almost undetectable in the first three month of pregnancy,and it began to rise slowly after the progesterone
    peak (4 - 6 month of gestation). These results provide references for changes of P and CG in pregnancy.