2种调查方法对四川黑竹沟国家级自然保护区3种雉类种群密度调查的比较

种群数量是物种的重要生态学基础资料,合适的密度调查方法是数量估算的基础。2016年4—5月,采用广泛应用于鸡形目Galliformes鸟类种群密度调查的样线法和样点法,调查了四川黑竹沟国家级自然保护区3种鸡形目鸟类(白腹锦鸡Chrysolophus amherstiae、红腹角雉Tragopan temminckii和血雉Ithaginis cruentus)的种群密度。样线法和样点法估算的雄体密度分别是:白腹锦鸡1.20只/km²和(6.31±0.98)只/km²,红腹角雉5.41只/km²和(0.39±0.17)只/km²,血雉3.01只/km²和(5.97±2.70)只/km²。除红腹角雉外,样点法估算的白腹锦鸡、血雉种群密度均大于样线法。建议针对不同鸡形目鸟类采用不同的调查方法,并尽量扩大样本数量,从而提高调查结果的准确性。     

A parentage evaluation test in North American Elk (Wapiti) using microsatellites of ovine and bovine origin

DNA microsatellites originally detected in sheep and cattle are also detectable in North American elk (Wapiti) using polymerase chain reactions. We have developed a parentage test in elk using eleven microsatellite markers that are highly polymorphic and informative.     

Rivastigmine Alleviates Experimentally Induced Colitis in Mice and Rats by Acting at Central and Peripheral Sites to Modulate Immune Responses

The cholinergic anti-inflammatory system and α7 nicotinic receptors in macrophages have been proposed to play a role in neuroimmunomodulation and in the etiology of ulcerative colitis. We investigated the ability of a cholinesterase (ChE) inhibitor rivastigmine, to improve the pathology of ulcerative colitis by increasing the concentration of extracellular acetylcholine in the brain and periphery. In combination with carbachol (10 µM), rivastigmine (1 µM) significantly decreased the release of nitric oxide, TNF-α, IL-1β and IL-6 from lipopolysaccharide-activated RAW 264.7 macrophages and this effect was abolished by α7 nicotinic receptor blockade by bungarotoxin. Rivastigmine (1 mg/kg) but not (0.5 mg/kg), injected subcutaneously once daily in BALB/c mice with colitis induced by 4% dextran sodium sulphate (DSS), reduced the disease activity index (DAI) by 60% and damage to colon structure. Rivastigmine (1 mg/kg) also reduced myeloperoxidase activity and IL-6 by >60%, and the infiltration of CD11b expressing cells by 80%. These effects were accompanied by significantly greater ChE inhibition in cortex, brain stem, plasma and colon than that after 0.5 mg/kg. Co-administration of rivastigmine (1 mg/kg) with the muscarinic antagonist scopolamine significantly increased the number of CD11b expressing cells in the colon but did not change DAI compared to those treated with rivastigmine alone. Rivastigmine 1 and 2 mg given rectally to rats with colitis induced by rectal administration of 30 mg dintrobezene sulfonic acid (DNBS) also caused a dose related reduction in ChE activity in blood and colon, the number of ulcers and area of ulceration, levels of TNF-α and in MPO activity. The study revealed that the ChE inhibitor rivastigmine is able to reduce gastro-intestinal inflammation by actions at various sites at which it preserves ACh. These include ACh released from vagal nerve endings that activates alpha7 nicotinic receptors on circulating macrophages and in brainstem neurons.     

Evidence for Linkage Disequilibrium Maintained by Selection in Two Natural Populations of DROSOPHILA SUBOBSCURA

One island and one mainland population of Drosophila subobscura were found polymorphic at the XDH (xanthine dehydrogenase) and the AO (aldehyde oxidase) loci. It was observed that one allele at the XDH locus, which has a low frequency in both populations, is nonrandomly associated with the alleles at the AO locus. Two lines of evidence support the thesis that this linkage disequilibrium is due to epistasis rather than random drift: (1) D or r, measures of the disequilibrium, have the same sign and magnitude in both populations. (2) The linkage disequilibrium is not due to inversions. Inversions segregating on the chromosome carrying XDH and AO have been separated into two classes, between which exchange of alleles at the two loci is suppressed. Linkage disequilibrium for XDH and AO was observed within each class. In the absence of any exchange of alleles, these disequilibria must have arisen and been maintained independently. The suggestion is made that the epistatic disequilibrium results from the close structural and physiological relationship which exists between the two enzymes.     

Demographic Inference Reveals African and European Admixture in the North American Drosophila melanogaster Population

Drosophila melanogaster spread from sub-Saharan Africa to the rest of the world colonizing new environments. Here, we modeled the joint demography of African (Zimbabwe), European (The Netherlands), and North American (North Carolina) populations using an approximate Bayesian computation (ABC) approach. By testing different models (including scenarios with continuous migration), we found that admixture between Africa and Europe most likely generated the North American population, with an estimated proportion of African ancestry of 15%. We also revisited the demography of the ancestral population (Africa) and found—in contrast to previous work—that a bottleneck fits the history of the population of Zimbabwe better than expansion. Finally, we compared the site-frequency spectrum of the ancestral population to analytical predictions under the estimated bottleneck model.     

Stilbene Synthase and Chalcone Synthase : Two Different Constitutive Enzymes in Cultured Cells of Picea excelsa

Cultured cells of Picea excelsa capable of forming stilbenes and flavanoids have been established. Unlike needles of intact plants containing piceatannol (3,3′,4′,5-tetrahydroxystilbene) and stilbene glycosides the cultured cells converted phenylalanine and p-coumaric acid primarily into resveratrol monomethyl ether (3,4′-dihydroxy-5-methoxystilbene) and naringenin. Partially purified enzyme preparations were assayed for chalcone synthase as well as for stilbene synthase activity converting malonyl-CoA plus p-coumaroyl-CoA into 3,4′,5-trihydroxystilbene (resveratrol).

Although stilbene synthase and chalcone synthase use the same substrates and exhibit similar molecular properties, i.e. molecular weight and subunit molecular weight, they are two different proteins. This difference was demonstrated by gel electrophoresis and by means of monospecific antibodies.

     

广西桂北地区HBV感染者不同免疫状态HBV基因型分布研究

为了了解广西桂北地区乙型肝炎病毒(Hepatitis B Virus,HBV)感染者基因型分布情况及探讨HBV感染不同免疫状态与基因型的关系。将HBV感染者按免疫耐受、免疫清除(应答)和免疫不全(病毒残留)三种免疫状态分类,各选150例,共450例,运用实时荧光定量PCR法检测HBV感染三种不同免疫状态者的HBV基因型。450例中B型为323例、C型为94例、B+C混合型为23例和非B非C型为10例;HBV感染三种免疫状态均B型占多数,分别为70.0%、78.0%和67.33%,不同免疫状态基因型构成比差异无统计学意义;免疫状态与基因型相关性无统计学意义;B型HBV-DNA载量高于C型,各组中年龄≥30岁者C型显著多于30岁者,差异有统计学意义;各基因型间丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、总胆红素(TBil)阳性率差别无统计学意义;男女基因型分布差异无统计学意义。结果表明,广西桂北地区HBV基因型以B型为主,C型占部分比例,少量B+C混合型,偶有未能分型;HBV感染免疫耐受、免疫清除(应答)和免疫不全(病毒残留)三种免疫状态均B型占多数,慢性HBV感染免疫状态与HBV基因型相关性无统计学意义。     

GPS Based Daily Activity Patterns in European Red Deer and North American Elk (Cervus elaphus): Indication for a Weak Circadian Clock in Ungulates

Long-term tracking using global positioning systems (GPS) is widely used to study vertebrate movement ecology, including fine-scale habitat selection as well as large-scale migrations. These data have the potential to provide much more information about the behavior and ecology of wild vertebrates: here we explore the potential of using GPS datasets to assess timing of activity in a chronobiological context. We compared two different populations of deer (Cervus elaphus), one in the Netherlands (red deer), the other in Canada (elk). GPS tracking data were used to calculate the speed of the animals as a measure for activity to deduce unbiased daily activity rhythms over prolonged periods of time. Speed proved a valid measure for activity, this being validated by comparing GPS based activity data with head movements recorded by activity sensors, and the use of GPS locations was effective for generating long term chronobiological data. Deer showed crepuscular activity rhythms with activity peaks at sunrise (the Netherlands) or after sunrise (Canada) and at the end of civil twilight at dusk. The deer in Canada were mostly diurnal while the deer in the Netherlands were mostly nocturnal. On an annual scale, Canadian deer were more active during the summer months while deer in the Netherlands were more active during winter. We suggest that these differences were mainly driven by human disturbance (on a daily scale) and local weather (on an annual scale). In both populations, the crepuscular activity peaks in the morning and evening showed a stable timing relative to dawn and dusk twilight throughout the year, but marked periods of daily a-rhythmicity occurred in the individual records. We suggest that this might indicate that (changes in) light levels around twilight elicit a direct behavioral response while the contribution of an internal circadian timing mechanism might be weak or even absent.     

Metabolic Quotient Measured by Free-Water Method in Six Enclosures with Different Silver Carp Densities

Quasi-continuous DO and pH measurements (total 47 days) were conducted during enclosure experiments (6 enclosures; 5 × 5 × 2.5 m), in which a biomass gradient of silver carp was created. After subtracting the air–water exchanges of O₂ and CO₂, the chemical and biochemical changes in DO (dissolved oxygen) and DIC (dissolved inorganic carbon) were estimated in order to evaluate MQ (metabolic quotient: DO change divided by DIC change) at intervals of 1 hour. By removing small absolute changes below the threshold value (0.01 mM h^?1), the averaged values of the 24 MQ means for the respective 1-hour periods ranged from 0.96 to 1.20 in the six enclosures. Because the MQs in the daytime inversely correlated well with the ratio of NH⁺ ₄–N to (NH⁺ ₄–N + NO^? ₃–N), not the ecosystems, i.e., density of fish, community structure of zooplankton and phytoplankton, but the form of nitrogen uptaken for primary production principally determined the MQs. The higher MQs observed in the daytime compared with the nighttime (from 14% to 21% except 3% for one enclosure) could not be explained by the denitrification and/or dissolution of CaCO₃ in the sediments, therefore suggesting the selectively faster decomposition of part of the organic matter provided through primary production, in other words, an accumulation of another part of the organic matter in the diurnal and/or daily time scale.     

Two Different Prunus SFB Alleles Have the Same Function in the Self-incompatibility Reaction

Many species in the families of Rosaceae, Solanaceae, and Scrophulariaceae exhibit gametophytic self-incompatibility, a phenomenon controlled by two polymorphic genes at the S-locus, style-S (S-RNase) and pollen-S (SFB). Sequences of both genes show high levels of diversity, characteristic of genes involved in recognition of self-incompatibility systems in plants. In this study, S ₂₄ -RNase and SFB ₂₄ alleles were cloned from Prunus armeniaca cv. Chuanzhihong (Chinese apricot). Sequence comparisons of deduced amino acid sequences revealed that the P. armeniaca S ₂₄ -haplotype has different SFB alleles, but shares a single S-RNase allele with P. armeniaca S ₄ -haplotype. Moreover, P. armeniaca S ₂₄ -RNase haplotype has a single and three different alleles with S ₁ -RNase of P. tenella (dwarf almond) and S ₁ -RNase of P. mira (smooth pit peach), respectively. The functionalities of SFB ₂₄ and SFB ₄ have been evaluated by pollen tube growth and controlled field tests of P. tenella and P. mira. Genetic analysis of the two intercrosses showed that progenies segregated 1:1 into two S-genotype classes, which is consistent with the expected ratio for semi-compatibility. These findings imply that the allelic function of the S ₂₄ -haplotype is identical to that of the S ₄ -haplotype in a self-incompatibility reaction. Thus, these two Prunus S-haplotypes are in fact two neutral variants of the same S-haplotype. The evolution of the S-allele is also discussed in terms of both functions and differences between S ₂₄ - and S ₄ -haplotypes in Prunus.     

Side Population in Human Non-Muscle Invasive Bladder Cancer Enriches for Cancer Stem Cells That Are Maintained by MAPK Signalling

Side population (SP) and ABC transporter expression enrich for stem cells in numerous tissues. We explored if this phenotype characterised human bladder cancer stem cells (CSCs) and attempted to identify regulatory mechanisms. Focusing on non-muscle invasive bladder cancer (NMIBC), multiple human cell lines were used to characterise SP and ABC transporter expression. In vitro and in vivo phenotypic and functional assessments of CSC behaviour were undertaken. Expression of putative CSC marker ABCG2 was assessed in clinical NMIBC samples (n = 148), and a role for MAPK signalling, a central mechanism of bladder tumourigenesis, was investigated. Results showed that the ABCG2 transporter was predominantly expressed and was up-regulated in the SP fraction by 3-fold (ABCG2^hi) relative to the non-SP (NSP) fraction (ABCG2^low). ABCG2^hi SP cells displayed enrichment of stem cell markers (Nanog, Notch1 and SOX2) and a three-fold increase in colony forming efficiency (CFE) in comparison to ABCG2^low NSP cells. In vivo, ABCG2^hi SP cells enriched for tumour growth compared with ABCG2^low NSP cells, consistent with CSCs. pERK was constitutively active in ABCG2^hi SP cells and MEK inhibition also inhibited the ABCG2^hi SP phenotype and significantly suppressed CFE. Furthermore, on examining clinical NMIBC samples, ABCG2 expression correlated with increased recurrence and decreased progression free survival. Additionally, pERK expression also correlated with decreased progression free survival, whilst a positive correlation was further demonstrated between ABCG2 and pERK expression. In conclusion, we confirm ABCG2^hi SP enriches for CSCs in human NMIBC and MAPK/ERK pathway is a suitable therapeutic target.     

Seasonal Variations in Population Dynamics of Key Intertidal Molluscs at Two Contrasting Locations

The paper deals with the spatial and the temporal variability of the population dynamics of five key molluscan species at two rocky intertidal shores on the southern Saurashtra coastline of India. The intertidal belts of the two selected stations, Veraval and Diu, are about 100 km apart and differ in their coast characteristics and level of human interference. The slope and the substrate types of the two stations are not uniform and the exposure of intertidal belt of these predominantly rocky shores during low tides is also not significantly long. The study revealed that a general, species specific pattern of spatial and temporal variations existed in the population abundance and density of the species studied. There was considerable spatial variability in some species examined but most species showed no clear seasonal trends for the population abundance. The Veraval coast, in spite of being affected by heavy human interference, is still a favourable place for Chiton, Turbo cornatus and Turbo intercoastalis than Diu, though the latter is relatively less affected by anthropogenic influences. It appears that the subtratum type, short exposure duration and moderate wave action of the Arabian Sea are most active controlling factors for higher distribution of these species at Veraval.     

North American arthropods at risk due to widespread Fraxinus mortality caused by the Alien Emerald ash borer

Emerald ash borer (Agrilus planipennis Fairmaire) (EAB), an alien invasive wood-boring buprestid beetle, is causing large-scale decline and mortality of the most widely distributed species of ash (Fraxinus spp.) trees endemic to eastern North America. We determined which arthropod species that are associated with ash may become threatened, endangered, and co-extinct with the demise of ash as a dominant tree species. A literature survey revealed that 43 native arthropod species in six taxonomic groups (Arachnida: Acari; Hexapoda: Coleoptera, Diptera, Hemiptera, Hymenoptera, and Lepidoptera) are known to be associated only with ash trees for either feeding or breeding purposes, and thus face high risk of endangerment. Most of these species are gall-formers followed by folivores, subcortical phloem/xylem feeders, sap feeders, and seed predators. Another 30 arthropod species are associated with 1–2 host plants in addition to ash, and herbivory on these hosts may increase as these arthropods shift from declining ash trees. Extirpation of arthropods dependent upon ash may unleash multiple extinctions of affiliated species with which they may be inextricably linked. The demise of North American ash species due to EAB is expected to lead to biotic loss with cascading ecological impacts and altered processes within forested ecosystems.     

American Marten Respond to Seismic Lines in Northern Canada at Two Spatial Scales

Development of hydrocarbon resources across northwest Canada has spurred economic prosperity and generated concerns over impacts to biodiversity. To balance these interests, numerous jurisdictions have adopted management thresholds that allow for limited energy development but minimize undesirable impacts to wildlife. Used for exploration, seismic lines are the most abundant linear feature in the boreal forest and exist at a variety of widths and recovery states. We used American marten (Martes americana) as a model species to measure how line attributes influence species’ response to seismic lines, and asked whether responses to individual lines trigger population impacts. Marten response to seismic lines was strongly influenced by line width and recovery state. Compared to forest interiors, marten used open seismic lines ≥ 3 m wide less often, but used open lines ≤ 2 m wide and partially recovered lines ≥ 6 m wide similarly. Marten response to individual line types appeared to trigger population impacts. The probability of occurrence at the home range scale declined with increasing seismic line density, and the inclusion of behavioral response to line density calculations improved model fit. In our top performing model, we excluded seismic lines ≤ 2 m from our calculation of line density, and the probability of occurrence declined > 80% between home ranges with the lowest and highest line densities. Models that excluded seismic lines did not strongly explain occurrence. We show how wildlife-derived metrics can inform regulatory guidelines to increase the likelihood those guidelines meet intended management objectives. With respect to marten, not all seismic lines constitute disturbances, but avoidance of certain line types scales to population impacts. This approach provides the ecological context required to understand cause and effect relationships among socio-economic and ecological conservation goals.     

Dim Light at Night Increases Immune Function in Nile Grass Rats,a Diurnal Rodent

With the widespread adoption of electrical lighting during the 20th century, human and nonhuman animals became exposed to high levels of light at night for the first time in evolutionary history. This divergence from the natural environment may have significant implications for certain ecological niches because of the important influence light exerts on the circadian system. For example, circadian disruption and nighttime light exposure are linked to changes in immune function. The majority of studies investigating the effects of light exposure and circadian disruption on the immune system use nocturnal rodents. In diurnal species, many hormones and immune parameters vary with secretion patterns 180° out of phase to those of nocturnal rodents. Thus, the authors investigated the effects of nighttime light exposure on immunocompetence in diurnal Nile grass rats (Arvicanthis niloticus). Rats were housed in either standard 14-h light (L):10-h dark (D) cycles with L ～150 lux and D 0 lux or dim light at night (dLAN) cycles of LD 14:10 with L ～150 lux and D 5 lux for 3 wks, then tested for plasma bactericidal capacity, as well as humoral and cell-mediated immune responses. Rats exposed to dLAN showed increased delayed-type hypersensitivity pinna swelling, which is consistent with enhanced cell-mediated immune function. dLAN rats similarly showed increased antibody production following inoculation with keyhole lymphocyte hemocyanin (KLH) and increased bactericidal capacity. Daytime corticosterone concentrations were elevated in grass rats exposed to nighttime dim light, which may have influenced immunological measures. Overall, these results indicate nighttime light affects immune parameters in a diurnal rodent. (Author correspondence: fonken.1@osu.edu)     

Comparative Genomic Analysis of Archaeal Genotypic Variants in a Single Population and in Two Different Oceanic Provinces

Planktonic crenarchaeotes are present in high abundance in Antarctic winter surface waters, and they also make up a large proportion of total cell numbers throughout deep ocean waters. To better characterize these uncultivated marine crenarchaeotes, we analyzed large genome fragments from individuals recovered from a single Antarctic picoplankton population and compared them to those from a representative obtained from deeper waters of the temperate North Pacific. Sequencing and analysis of the entire DNA insert from one Antarctic marine archaeon (fosmid 74A4) revealed differences in genome structure and content between Antarctic surface water and temperate deepwater archaea. Analysis of the predicted gene products encoded by the 74A4 sequence and those derived from a temperate, deepwater planktonic crenarchaeote (fosmid 4B7) revealed many typical archaeal proteins but also several proteins that so far have not been detected in archaea. The unique fraction of marine archaeal genes included, among others, those for a predicted RNA-binding protein of the bacterial cold shock family and a eukaryote-type Zn finger protein. Comparison of closely related archaea originating from a single population revealed significant genomic divergence that was not evident from 16S rRNA sequence variation. The data suggest that considerable functional diversity may exist within single populations of coexisting microbial strains, even those with identical 16S rRNA sequences. Our results also demonstrate that genomic approaches can provide high-resolution information relevant to microbial population genetics, ecology, and evolution, even for microbes that have not yet been cultivated.     

Population structure in the American oyster as inferred by nuclear gene genealogies

Multiple haplotypes from each of three nuclear loci were isolated and sequenced from geographic populations of the American oyster, Crassostrea virginica. In tests of alternative phylogeographic hypotheses for this species, nuclear gene genealogies constructed for these haplotypes were compared to one another, to a mitochondrial gene tree, and to patterns of allele frequency variation in nuclear restriction site polymorphisms (RFLPs) and allozymes. Oyster populations from the Atlantic versus the Gulf of Mexico are not reciprocally monophyletic in any of the nuclear gene trees, despite considerable genetic variation and despite large allele frequency differences previously reported in several other genetic assays. If these populations were separated vicariantly in the past, either insufficient time has elapsed for neutral lineage sorting to have achieved monophyly at most nuclear loci, or balancing selection may have inhibited lineage extinction, or secondary gene flow may have moved haplotypes between regions. These and other possibilities are examined in light of available genetic evidence, and it is concluded that no simple explanation can account for the great variety of population genetic patterns across loci displayed by American oysters. Regardless of the source of this heterogeneity, this study provides an empirical demonstration that different sequences of DNA within the same organismal pedigree can have quite different phylogeographic histories.