133 resultados para lan-ohiturak
Resumo:
描述了采自广西都安县红水河水系的条鳅亚科鱼类2 个新种: 丽纹云南鳅Yunnanilus pulcherrimus sp1nov. 在侧线长度、鳞片分布、鳍条数目、尾型、吻须长度等方面与侧纹云南鳅Yunnanilus pleurotaenia (Re2 gan , 1904) 最为相似, 但新种独特的斑纹和上下唇的长乳突可明显与之区别, 二者在一些度量特征上也有区 别。黄体高原鳅Triplophysa f lavicorpus sp1nov1 与同分布于西江水系的南丹高原鳅T. nandanensis Lan et al1 较为 相似, 并以下列特征组合与高原鳅属所有已知种相区别: 背鳍分枝鳍条10 根、臀鳍分枝鳍条6~7 根、体被细 鳞、侧线完全、具6 条宽横斑和1 条沿侧线的细纵纹、尾鳍深分叉、尾鳍基具1 半圆形黑斑、尾鳍上下叶各具 2 条黑色横斑、腹鳍末端后伸超过肛门、腋部具发达的肉质鳍瓣、上唇中央完全中断等。云南鳅属和高原鳅属 均是高原特有类群, 前者仅分布于云南东中部地区, 后者则集中分布于青藏高原。两个新种的分布地均远离这 两个属的分布中心, 而且呈间断分布。通过各自相近种谱系关系分析, 推测这种特殊的分布格局是通过隔域分 化形成的。
Resumo:
2003 年1 月, 在广西壮族自治区天峨县红水河水系地下河采集到一批盲鱼标本。经鉴定, 为高原鳅 属Triplophysa 一未经发表的新种。新种天峨高原鳅Triplophysa tianeensis sp1nov1 与个旧盲高原鳅T. gejiuensis 、 石林盲高原鳅T. shilinensis 、阿庐高原鳅T. aluensis 和南丹高原鳅T. nandanensis 相似; 本新种腹鳍末端不达 肛门, 尾鳍分枝鳍条16 , 可进一步与个旧盲高原鳅和石林盲高原鳅(腹鳍末端达到肛门, 尾鳍分枝鳍条14~ 15) 相区别; 本新种背鳍起点位于体之中点、腹鳍起点之后, 肛门紧靠臀鳍起点, 可进一步与阿庐高原鳅(背 鳍起点靠近吻端、位于腹鳍起点之前, 肛门距臀鳍起点仍有一段距离) 相区别。本新种与同分布于红水河水系 的南丹高原鳅Triplophysa nandanensis Lan et al1 较为相似; 但二者区别明显: 新种背鳍分枝鳍条7 、胸鳍分枝鳍 条9 、腹鳍分枝鳍条6 、背鳍外缘平截、背鳍起点位于腹鳍起点之后, 后者背鳍分枝鳍条8 、胸鳍分枝鳍条10~ 11 、腹鳍分枝鳍条7 、背鳍外缘凹入、背鳍起点位于腹鳍起点之前; 此外, 新种的穴居特征更为显著: 眼极度 退化、头长为眼径1618~3218 (2510) 倍、部分个体无色素斑且各鳍无斑点, 而南丹高原鳅眼小、头长为眼径 417~910 (715) 倍、体和头背侧密布云状斑且各鳍均具点状斑。
Resumo:
The formation of memory is believed to depend on experience- or activity-dependent synaptic plasticity, which is exquisitely sensitive to psychological stress since inescapable stress impairs long-term potentiation (LTP) but facilitates long-term depression (LTD). Our recent studies demonstrated that 4 days of opioid withdrawal enables maximal extents of both hippocampal LTP and drug-reinforced behavior; while elevated-platform stress enables these phenomena at 18 h of opioid withdrawal. Here, we examined the effects of low dose of morphine (0.5 mg kg(-1), i.p.) or the opioid receptor antagonist naloxone (1 mg kg(-1), i.p.) on synaptic efficacy in the hippocampal CA1 region of anesthetized rats. A form of synaptic depression was induced by low dose of morphine or naloxone in rats after 18 h but not 4 days of opioid withdrawal. This synaptic depression was dependent on both N-methyl-D-aspartate receptor and synaptic activity, similar to the hippocampal long-term depression induced by low frequency stimulation. Elevated-platform stress given 2 h before experiment prevented the synaptic depression at 18 h of opioid withdrawal; in contrast, the glucocorticoid receptor (GR) antagonist RU38486 treatment (20 mg kg(-1), s.c., twice per day for first 3 days of withdrawal), or a high dose of morphine reexposure (15 mg kg(-1), s.c., 12 h before experiment), enabled the synaptic depression on 4 days of opioid withdrawal. This temporal shift of synaptic depression by stress or GR blockade supplements our previous findings of potentially correlated temporal shifts of LTP induction and drug-reinforced behavior during opioid withdrawal. Our results therefore support the idea that stress experience during opioid withdrawal may modify hippocampal synaptic plasticity and play important roles in drug-associated memory. (C) 2009 Wiley-Liss, Inc.
Resumo:
A new species, Triplophysa longipectoralis, is described from Liujiang River, Guangxi, China. The new species is distinguished from other species of Triplophysa by the following combination of characters: pectoral fin highly developed, reaching beyond pel
Resumo:
A new species, Pseudogyrinocheilus longisulcus, was discovered from a tributary of Pearl River in Jingxi Co., Guangxi, China, The new species can be distinguished from other species of Pseudogyrinocheilus by the following combination of characteristics: prolonged post-labial grooves, and extended antero-medially close to anterior end of middle lower lip, but not meeting with its counterpart; posterior margin of lower lip free; scales of abdomen from thorax to pectoral-fin base embedded under skin; lateral-line scales 40-42; dark stripe longitudinal along lateral line on flank. The key to the species of Pseudogyrinocheilus is provided.
Resumo:
Mitochondrial DNA (mtDNA) of six breeds of native domestic pigs from Yunnan province, southwest China, and two wild boars obtained from Sichuan, China, and Vietnam was analyzed using 20 restriction endonucleases that recognize six nucleotides. Restriction maps were made by double-digestion methods and polymorphic sites were located on the map. According to their mtDNA restriction types, all the breeds were classified into six groups. Genetic distances among groups were calculated to define their phylogenetic relationships. The relationship between the Sichuan wild boar and domestic pigs is close, while the Vietnamese wild boar is relatively far from them, so the domestic pigs in southwest China are likely to have originated from a wild pig which distributed in west China. We compare our results with previous reports in literature and discuss the relationship among Chinese pigs, Japanese pigs, and European pigs. The mtDNA cleavage pattern of the Mingguang pig digested by EcoRV was identical to that of Duroc; mutations at the EcoRI site, detected in the mtDNA of two Dahe pigs, are the same as in the Vietnamese wild boar, suggesting that mutational hot spots exist in the mtDNA of pigs.
Resumo:
Feeding and vocal behaviours of wild black gibbons (Hylobates concolor) were observed from 1987 to 1989 in south-western Yunnan, notably H. concolor jingdongensis at Mt. Wuliang (24-degrees 18-42'N, 100-degrees 30-50'E) in the early spring of 1989. 12 plant species were observed to have been eaten by the gibbons; these included tree species, lianas and epiphytes. Approximately 21 % of feeding time was devoted to eating fruits, 61 % to leaf buds and shoots, 7 % to flowers and 11 % to leaves. The gibbons preferred fruits to leaves even though they commonly ate leaves. In this study, the morning songs (duet and solo), reponsive (territorial) songs, alarm calls and communication calls were recorded. The gibbons sang their morning songs mainly in the early morning, with a single bout lasting more than 10 min on average. The singing of a group would trigger other groups, and all groups in an area tended to sing sequentially. The morning duet song bout was dominated by an adult male. The male emitted booms, aa notes, early multimodulated figures, intermediate multimodulated figures and codas, the latter occurring only in duets following the female's great call. The female uttered great calls and abortive great calls. The subadults or juveniles also took part in the morning songs. Lone males were heard to utter solos which lasted longer than the duets of the pairs.
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Twelve restriction endonucleases were employed to analyze the mitochondrial DNA of four species of muntjacs and two related species of deer: red muntjac (M. muntjak), Gongshan muntjac (M. gongshanensis), black muntjac (M. crinifrons), Chinese muntjac (M. reevesi), tufted deer (Elaphodus cephalophus), and forest musk deer (Moschus berezovskii). A total of 170 restriction fragments were detected among the samples. Fragments data were used to calculate the genetic distance (i.e. percent sequence divergency) among species, which in turn were used to construct a phylogenetic tree and to estimate divergency times. Our analysis indicates that the black muntjac and the Gongshan muntjac are most closely related, and that they are closely realted to the red muntjac and the Chinese muntjac. Additionally, the tufted deer is genetically closer to muntjacs than the musk deer is.
Resumo:
Gene mapping of a mouse coat mutation has been investigated. First, 100 10-bp random primers were used to amplify DNA, but the mutation could not be located by this method because there were no correlation between the amplified products and coat phenotypes. Second, by using Idh1, Car2, Mup1, Pgb1, Hbb, Es10, Es1, Mod1, Gdc1, Ce2, Es3 as genetic markers, linkage test crosses (two-point test) consisting of intercrossing uncovered BALB/c mice (homozygotes) to CBA/N and C57BL/6 mice with normal hair and backcrossing the heterozygotes of the F1 to the uncovered BALB/c mice were made. It was soon evident that the mutation was linked to Es3 on chromosome 11. Furthermore, three-point test was made by using Es3 and D11Mit8 (a microsatellite DNA) as genetic markers. The result showed that the mutation was linked to Es3 with the percentage recombination of (7.89 +/- 2.19)%, and linked to D11Mit8 with the percentage recombination of (26.38 +/- 3.57)%. The percentage recombination between Es3 and D11Mit8 was (32.90 +/- 3.81)%. The mutation was named Uncovered, with the symbol Uncv. According to the recombinations, the loci order was D11Mit8-26.30 +/- 3.57- Uncv-7.89 +/- 2.19-Es3. From the location on the chromosome, it was concluded that the mutation was a new mutation which affected the skin and hair structure of mouse. The Uncv has entered MGD (Mouse Genome Database).
Resumo:
Elevational and latitudinal patterns of species richness for birds and mammals were compared with human population density in relation to nature reserve designation in two areas of Yunnan Province, China. Results suggest that species richness is not the same for the two areas. In Gaoligongshan Region, species richness is inversely correlated with elevation and altitude, while reserve designation is positively correlated with elevation and latitude. In Jingdong County, reserve designations are positively correlated with elevation, but species richness shows no clear trends. In general, the present situation is strongly influenced by human activities. It appears that reserve designation is mismatched with species richness in Gaoligongshan Region, while there is a better fit between the two in Jingdong County. In both areas, however, it appeared that reserves were located primarily in order to reduce conflict with humans rather than to maximize conservation of biodiversity, probably because humans were responsible for forest-especially primary forest-destruction and degradation in the low-lying areas.
Resumo:
Algal bloom phenomenon was defined as "the rapid growth of one or more phytoplankton species which leads to a rapid increase in the biomass of phytoplankton", yet most estimates of temporal coherence are based on yearly or monthly sampling frequencies and little is known of how synchrony varies among phytoplankton or of the causes of temporal coherence during spring algal bloom. In this study, data of chlorophyll a and related environmental parameters were weekly gathered at 15 sampling sites in Xiangxi Bay of Three-Gorges Reservoir (TGR, China) to evaluate patterns of temporal coherence for phytoplankton during spring bloom and test if spatial heterogeneity of nutrient and inorganic suspended particles within a single ecosystem influences synchrony of spring phytoplankton dynamics. There is a clear spatial and temporal variation in chlorophyll a across Xiangxi Bay. The degree of temporal coherence for chlorophyll a between pairs of sites located in Xiangxi Bay ranged from -0.367 to 0.952 with mean and median values of 0.349 and 0.321, respectively. Low levels of temporal coherence were often detected among the three stretches of the bay (Down reach, middle reach and upper reach), while high levels of temporal coherence were often found within the same reach of the bay. The relative difference of DIN between pair sites was the strong predictor of temporal coherence for chlorophyll a in down and middle reach of the bay, while the relative difference in Anorganic Suspended Solids was the important factor regulating temporal coherence in middle and upper reach. Contrary to many studies, these results illustrate that, in a small geographic area (a single reservoir bay of approximately 25 km), spatial heterogeneity influence synchrony of phytoplankton dynamics during spring bloom and local processes may override the effects of regional processes or dispersal.
Resumo:
Dew is an important water source for desert organisms in semiarid and arid regions. Both field and laboratory experiments were conducted to investigate the possible roles of dew in growth of biomass and photosynthetic activity within cyanobacterial crust. The cyanobacteria, Microcoleus vaginatus Gom. and Scytonema javanicum (Kutz.) Born et Flah., were begun with stock cultures and sequential mass cultivations, and then the field experiment was performed by inoculating the inocula onto shifting sand for forming cyanobacterial crust during late summer and autumn of 2007 in Hopq Desert, northwest China. Measurements of dew amount and Chlorophyll a content were carried out in order to evaluate the changes in crust biomass following dew. Also, we determined the activity of photosystem II(PSII) within the crust in the laboratory by simulating the desiccation/rehydration process due to dew. Results showed that the average daily dew amount as measured by the cloth-plate method (CPM) was 0.154 mm during fifty-three days and that the crust biomass fluctuated from initial inoculation of 4.3 mu g Chlorophyll a cm(-2) sand to 5.8-7.3 mu g Chlorophyll a cm(-2) crust when dew acted as the sole water source, and reached a peak value of approximately 8.2 mu g Chlorophyll a cm(-2) crust owing to rainfalls. It indicated that there was a highly significant correlation between dew amounts and crust moistures (r = 0.897 or r = 0.882, all P < 0.0001), but not a significant correlation between dew and the biomass (r = 0.246 or r = 0.257, all P > 0.05), and thus concluded that dew might only play a relatively limited role in regulating the crust biomass. Correspondingly, we found that rains significantly facilitated biomass increase of the cyanobacterial crust. Results from the simulative experiment upon rehydration showed that approximately 80% of PSII activity could be achieved within about 50 min after rehydration in the dark and at 5 degrees C, and only about 20% of the activity was light-temperature dependent. This might mean that dew was crucial for cyanobacterial crust to rapidly activate photosynthetic activity during desiccation and rehydration despite low temperatures and weak light before dawn. It also showed in this study that the cyanobacterial crusts could receive and retain more dew than sand, which depended on microclimatic characteristics and soil properties of the crusts. It may be necessary for us to fully understanding the influence of dew on regulating the growth and activity of cyanobacterial crust, and to soundly evaluate the crust's potential application in fighting desertification because of the available water due to dew. (C) 2009 Published by Elsevier Ltd.
Characterization of the porcine differentially expressed PDK4 gene and association with meat quality
Resumo:
To investigate the differential expression of genes in the skeletal muscle between Yorkshire and Chinese indigenous breed Meishan pigs, suppression subtractive hybridization was carried out and many genes were proved to be expressed significantly different in the two breeds. One gene highly expressed in Meishan but lowly expressed in Yorkshire specific library, shared strong homology with human pyruvate dehydrogenase kinase 4 (PDK4). Using semi-quantity and quantity PCR, We confirmed its differential expression between the two breeds. Temporal and spatial expression analysis indicated that porcine PDK4 gene is highly expressed in skeletal muscle and the highest in neonatal pigs. Complete cDNA cloning and sequence analysis revealed that porcine PDK4 gene contains an open reading frame of 1,221 bp. The deduced amino acid sequence showed conservation in evolution. A G/A mutation in intron 9 was identified and association analysis showed that it was significantly associated with intramuscular fat, muscle water content.