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1.
目的:研究长期酒精摄入对雄性大鼠生殖系统的损伤机制。方法:选用8周龄的SD大鼠,进行随机分组:对照组(5%蔗糖,口服);酒精组(4g/kg,口服)。连续12周后,分别取附睾考察精子数目、活力;取血清检测睾酮和促黄体生产素(LH)含量;计算睾丸一体重比,并检测睾丸中丙二醛(MDA)、谷胱甘肽(GSH)含量以及谷胱甘肽过氧化物酶(GPx)和超氧化物歧化酶(SOD)的活性;同时检测凋亡相关蛋白bax,bcl-2以及caspase.3前体和剪切体的蛋白表达。结果:酒精组12周后,大鼠的睾丸.体重比明显降低(P〈0.05),精子数目减少(P〈0.01),精子活力下降(P〈0.01);血清中睾酮含量下降(P〈0.05),LH含量增加(P〈0.05);睾丸中MDA含量增加(P〈0.01),GSH含量降低(P〈0.05),GPX和SOD活性下降(P〈0,01);凋亡相关蛋白bax表达增加(P〈0.05),caspase-3剪切体与前体的比值增加(P〈O.01)。结论:长期摄入酒精引起的大鼠睾丸内氧化应激水平的增加是其导致其生殖系统损伤的重要因素之一。  相似文献   

2.
大豆黄酮对大鼠肌肉生长和几种内源激素水平的影响   总被引:55,自引:0,他引:55  
给雄性、雌性和雄性去势大鼠皮下注射大豆黄酮[3mg/(100g体重·天)]16天。结果:雄性大鼠日增重提高14.7%(P<0.05),耗料与增重比降低12.0%,后腿肌重和后腿肌总RNA含量显著增加,而总DNA含量无显著变化;血清脲氮水平显著下降,血清睾酮、雌二醇、生长激素和β-内啡肽含量显著提高。雄性去势大鼠日增重、后腿肌重无显著变化,血清睾酮、生长激素和β-内啡肽水平虽显著高于对照组,但睾酮水平仅为同等条件下完整大鼠的8%左右。雌性大鼠日增重降低19.0%(P<0.01),耗料与增重比提高17.8%,血清睾酮、雌二醇和生长激素水平显著降低。试验结果表明:大豆黄酮对大鼠肌肉生长和几种内源激素水平的影响呈现性别差异,对雄性大鼠肌肉生长的促进作用依赖于睾丸的内分泌机能。  相似文献   

3.
目的:探讨一次大强度运动对骨骼肌收铺蛋白降解和26S蛋白酶体活性的影响。方法:36只雄性Sprague—Dawley大鼠随机分为6组:安静对照组、运动0.5小时组、运动1小时组、运动后1小时组、运动后2小时组、运动后6小时组,每组6只。运动方式采用一次大强度跑台运动,速度为25m/min,坡度为5%,运动时间分别为0.5小时和1小时。每组按规定时间取材大鼠腓肠肌,观察其3.甲基组氨基酸(3-MH)含量、26S蛋白酶体活性和26S蛋白酶体C2亚基mRNA表达的变化。结果:(1)运动后即刻和运动后6小时大鼠腓肠肌中3-MH含量比安静时高(P〈0.01),其中运动0.5小时即刻含量最高(P〈0.01);(2)运动0.5小时后即刻、运动后6小时大鼠腓肠肌26S蛋白酶体活性高于安静水平(P〈0.05)。(3)运动后6小时大鼠腓肠肌26S蛋白酶体C2亚基mRNA表达高于安静水平(P〈0.01),其它时间点低于安静水平。结论:运动后26S蛋白酶体活性增高可能促使骨骼肌收缩蛋白降解增强,其活性受亚基基因调控。  相似文献   

4.
目的:观察电针不同穴位对慢性炎症痛模型大鼠行为学改变的影响,进一步探讨电针对慢性痛所致心理行为改变的调节规律:方法:将40只雄性Wistar大鼠随机分为正常组、模型组、电针百会组、电针关元组、电针足三里组,每组各8只。除正常组外,其余各组均采用弗氏完全佐剂(CFA)制备佐剂性关节炎(AA,即慢性炎症痛)大鼠模型,于造模第2天各治疗组捆绑固定后给予电针20min,正常组及模型组捆绑束缚20min,隔日一次,共10次。于造模前、造模后、治疗5次、10次分别采用高架十字迷宫检测各组大鼠开放臂进入次数比例(OE%)及开放臂停留时间比例(OT%)的变化。结果:与造模前比较,电针百会穴组大鼠造模后0E%和0T%明显减少(P〈0.05,P〈0.05),且治疗5次后OT%、治疗10次后0E%与0T%均降低明显(P〈0.01,P〈0.01,P〈0.05),而电针关元组大鼠治疗10次后OE%和OT%则明显升高(P〈0.05,P〈0.05),电针足三里组大鼠造模后0T%、治疗5次后大鼠OE%与OT%、治疗10次后OT%均明显降低(P〈O.01,P〈0.05,P〈0.01,P〈0.05);与造模刚结束比较,电针百会组大鼠在治疗5次、10次后0E%由升高逐步降低,而OT%由低逐渐升高(P〉0.05),电针关元组模型大鼠治疗10次后模型大鼠0E%和0T%均明显升高(P〈0.05,P〈0.05),电针足三里组模型大鼠治疗10次后OT%升高明显(P〈0.05);与治疗5次后比较,电针百会组大鼠在治疗10次后OE%降低、OT%升高(P〉O.05),电针关元组与电针足三里组大鼠治疗10次后OE%和OT%均明显升高(P〈0.05,P〈0.05;P〈0.01,P〈0.01)。与电针百会组比较,电针关元组与电针足三里组大鼠在治疗10次时OE%均明显升高(P〈0.01,P〈0.01)结论:电针不同穴位具有一定抗抑郁和抗焦虑作用,可改善慢性炎症痛所致大鼠焦虑、情绪行为的变化;不同穴位效应不同,关元穴与足三里穴具有综合调节、抗焦虑效应,且具有相对特异性。  相似文献   

5.
Lu JQ  Liu WF  Tang CF 《中国应用生理学杂志》2011,27(3):361-2, 371, 383
目的:探索睡眠剥夺对大鼠运动能力及谷氨酰胺含量变化的影响,为睡眠剥夺后的运动训练等提供一定的实验依据。方法:将30只雄性SD大鼠按体重随机分安静对照组、0h睡眠剥夺力竭运动组(SDE)、24h SDE、48h SDE和72h SDE组(n=6),采用轻柔刺激法建立睡眠剥夺模型和依据Bedford建立的大鼠运动模型。结果:24h SDE睡眠剥夺组与0h SDE组比较。大鼠后蹬跑时间明显长(P〈0.05),48h SDE睡眠剥夺组和72h SDE睡眠剥夺与0h SDE睡眠剥夺组比较,后蹬跑时间显著性减少(P〈0.01);24h SDE睡眠剥夺组与c组比较大鼠胸腺谷氨酰胺含量显著升高(P〈0.05),48h SDE睡眠剥夺组和72h SDE睡眠剥夺组与C组比较大鼠胸腺谷氨酰胺含量降低(P〈0.01);睡眠剥夺组与C组比较,血清谷氨酰胺含量的变化均具有高度显著性差异(P〈0.01),睡眠剥夺24h后血清谷氨酰胺含量显著增多,却在睡眠剥夺48h、72h后血清谷氨酰胺含量明显下降。结论:①睡眠剥夺24h能提高大鼠运动能力,睡眠剥夺48h甚至是72h后大鼠运动能力开始降低。②睡眠剥夺24h后大鼠胸腺谷氨酰胺含量和血清谷氨酰胺含量升高,而睡眠剥夺48h后大鼠胸腺和血清的谷氨酰胺含量下降明显,睡眠剥夺72h后胸腺和血清谷氨酰胺含量显著性降低。  相似文献   

6.
目的:研究大豆异黄酮对辐射小鼠免疫器官脾脏的影响。方法:90只雄性昆明小鼠,随机分为正常组、对照组和补充0.5%大豆异黄酮组,喂养两周后,4.0Gyγ射线照射;于照射后12、24h和一周、两周杀死部分小鼠取脾脏,测定小鼠的脾脏指数、脾脏细胞周期、细胞增殖指数及细胞凋亡率等指标。结果:辐射使小鼠脾脏明显萎缩。脾脏细胞凋亡率和G0-C1期细胞百分比明显增加(P〈0.05),脾脏细胞S期的百分比及细胞增殖指数明显降低(P〈0.01);补充大豆异黄酮,可使上述指标更接近正常组水平,使脾脏细胞G0-C1期百分比较辐射对照组明显减少(P〈0.05),脾脏细胞的C2-M期百分比和细胞增殖指数较辐射对照组明显增加(P〈0.05)。结论:大豆异黄酮可对脾脏起到辐射防护的作用。  相似文献   

7.
目的:探讨饮用啤酒与运动对糖尿病(DM)大鼠血糖和血脂代谢的影响。方法:将造模成功的DM大鼠分成饮用啤酒组、运动组、饮用啤酒加运动组和单纯DM组(n=10),8周后进行相关指标的测定。结果:DM运动组血糖、甘油三酯(TC)、总胆固醇(TG)和低密度脂蛋白(LDL-C)含量显著低于DM组(P〈0.05),胰岛素、高密度脂蛋白(HDL-C)含量明显高于DM组(P〈0.05);DM饮啤酒组血糖含量非常显著高于DM组(P〈O.01),1℃和TG含量显著低于DM组(P〈0.05);DM饮啤酒加运动组TG含量非常显著低于DM组(P〈O.01),LDL-C含量显著低于DM组(P〈O.05),HDL-C含量非常显著高于DM组(P〈0.01)。结论:运动可有效降低DM大鼠血糖和血脂含量,增强胰岛素和HDL-C的合成;饮用啤酒可使DM大鼠血糖极显著升高,但可促进DM大鼠血脂的代谢;运动对降低饮用啤酒导致的DM大鼠血糖升高具有良好作用,并可显著升高HDL-C含量,降低TG和LDL-C含量。改善DM大鼠的血脂代谢。  相似文献   

8.
陈晓明  游运辉  罗卉  贺立新 《生物磁学》2011,(17):3266-3269
目的:研究来氟米特和依那西普联合使用对佐剂性关节炎(AA)大鼠的治疗作用及其可能的作用机制。方法:建立AA大鼠关节炎模型,分为正常对照组、模型组、来氟米特组、依那西普组、来氟米特联合依那西普配伍组;采用关节炎指数评分法评价大鼠关节炎症程度,半定量RT-PCR和放射免疫法检测滑膜组织及血清中IL-1β、TNF-α表达水平,免疫组化方法检测滑膜组织中MMP-3含量。结果:①相较于AA模型组,来氟米特组、依那西普组和配伍组中大鼠的AI评分均显著下降(P〈0.01),其中以配伍组关节炎指数为最低(P〈0.05)。②模型组大鼠血清及滑膜组织的IL-1β和TNF-α水平明显高于正常对照组(P〈0.01),用药后各组的IL-1β和TNF-α水平均有所下降,并以配伍组降低最为明显(P〈0.01或P〈0.05);③模型组大鼠滑膜组织MMP-3表达阳性密度显著高于正常对照组(P〈0.01),用药后备组的MMP-3阳性密度降低(P〈0.01),其中配伍组下降程度明显高于来氟米特组和依那西普组(P〈0.01)。结论:来氟米特和依那西普联合使用可明显减轻AA大鼠的关节炎症,降低血清和滑膜组织中IL-1β和TNF-α平,减少滑膜中MMP-3的表达,疗效优于单独使用来氟米特或依那西普。  相似文献   

9.
目的:探讨大鼠吸入低浓度SO2后引起气道损伤以及气道反应性的变化与相关的病理生理机制。方法:SD雄性大鼠16只,随机分为2组(n=8):对照组和SO2组。对照组暴露于正常空气中。SO2组暴露于含量为1.0mg/(m3·h)的SO2室内空气中,每天6h,连续3d,第4d测大鼠气道反应性,采集血清、收集支气管肺泡灌洗液(BALF),留取肺组织。分别进行BALF细胞计数,测血清中P物质(SP)的含量,作肺组织病理切片行HE及SP免疫组化染色。结果:SO2组与对照组比较,大鼠的气道反应性增高(P〈0.01),BALF中细胞总数明显升高(P〈0.01);血清SP含量显著增加(P〈0.01)。肺组织病理切片UE染色显示SO2组支气管粘膜下有大量炎性细胞浸润;免疫组化染色提示SO2组SP免疫阳性神经纤维数量明显增加(P〈0.05)。结论:吸入SO2诱发大鼠出现气道高反应性,气道内感觉神经源性炎症是其重要的病理生理机制之一。  相似文献   

10.
目的:诱导大鼠产生酒精依赖,观察大鼠产生的躯体依赖及行为学改变。方法:20只雄性SD大鼠,其中饮酒组和对照组各10只。通过6%(v/v)酒精溶液作为饮酒组大鼠唯一饮水来源共28d,测量血酒精浓度。根据旷场行为、戒断症状和强迫游泳等方法来判断是否成功诱导大鼠产生酒精躯体依赖及动机行为改变。结果:整个实验过程饮酒组大鼠血酒精浓度没有发生明显变化。饮酒组大鼠旷场测试中水平活动量在饮酒第7d比对照组显著降低(P〈0.05);垂直活动量在饮酒第7、14d比对照组显著降低(P〈0.05);饮酒组大鼠戒断2-48h酒精戒断评分均显著高于对照组(P〈0.01)且评分在戒断第6h最高;戒断24、48h的大鼠在强迫游泳中绝对不动时间比对照组显著延长(P〈0.05)。结论:大鼠持续饮用6%(v/v)浓度酒精溶液可以诱导出大鼠对酒精的严重躯体依赖和抑郁状态,并抑制大鼠在新奇环境中的活动能力和动机行为。  相似文献   

11.
D-xylose is a necessary sugar for animals. The xylanase from a mollusk, Ampullaria crossean, was previously reported by our laboratory. This xylanase can degrade the xylan into D-xylose. But there is still a gap in our knowledge on its metabolic pathway. The question is how does the xylose enter the pentose pathway? With the help of genomic databases and bioinformatic tools, we found that some animals, such as bacteria, have a highly conserved D-xylose isomerase (EC 5.3.1.5). The xyiose isomerase from a sea squirt, Ciona intestinali, was heterogeneously expressed in Escherichia coli and purified to confirm its function. The recombinant enzyme had good thermal stability in the presence of Mg^2+. At the optimum temperature and optimum pH environment, its specific activity on D-xylose was 0.331 μmol/mg/min. This enzyme exists broadly in many animals, but it disappeared in the genome of Amphibia-like Xenopus laevis. Its sequence was highly conserved. The xylose isomerases from animals are very interesting proteins for the study of evolution.  相似文献   

12.
Long-term preservation of recalcitrant seeds is very difficult because the physiological basis on their desiccation sensitivity is poorly understood. Survival of Antiaris toxicaria axes rapidly decreased and that of immature maize embryos very slowly decreased with dehydration. To understand their different responses to dehydration, we examined the changes in mitochondria activity during dehydration. Although activities of cytochrome (Cyt) c oxidase and malate dehydrogenase of the A. toxicaria axis and maize embryo mitochondria decreased with dehydration, the parameters of maize embryo mitochondria were much higher than those of A. toxicaria, showing that the damage was more severe for the A. toxicaria axis mitochondria than for those of maize embryo. The state I and III respiration of the A. toxicaria axis mitochondria were higher than those of maize embryo, the former rapidly decreased, and the latter slowly decreased with dehydration. The proportion of Cyt c pathway to state III respiration for the A. toxicaria axis mitochondria was low and rapidly decreased with dehydration, and the proportion of alternative oxidase pathway was high and slightly increased with dehydration. In contrast, the proportion of Cyt c pathway for maize embryo mitochondria was high, and that of alternative oxidase pathway was low. Both pathways decreased slowly with dehydration.  相似文献   

13.
Phosphoribulokinase (PRK), a nuclear-encoded plastid-localized enzyme unique to the photosynthetic carbon reduction (Calvin) cycle, was cloned and characterized from the stramenopile alga Vaucheria litorea. This alga is the source of plastids for the mollusc (sea slug) Elysia chlorotica which enable the animal to survive for months solely by photoautotrophic CO2 fixation. The 1633-bp V. litorea prk gene was cloned and the coding region, found to be interrupted by four introns, encodes a 405-amino acid protein. This protein contains the typical bipartite target sequence expected of nuclearencoded proteins that are directed to complex (i.e. four membrane-bound) algal plastids. De novo synthesis of PRK and enzyme activity were detected in E. chlorotica in spite of having been starved of V. litorea for several months. Unlike the algal enzyme, PRK in the sea slug did not exhibit redox regulation. Two copies of partial PRK-encoding genes were isolated from both sea slug and aposymbiotic sea slug egg DNA using PCR. Each copy contains the nucleotide region spanning exon 1 and part of exon 2 of V litorea prk, including the bipartite targeting peptide. However, the larger prk fragment also includes intron 1. The exon and intron sequences of prk in E. chlorotica and V/itorea are nearly identical. These data suggest that PRK is differentially regulated in V. litorea and E. chlorotica and at least a portion of the V. litorea nuclear PRK gene is present in sea slugs that have been starved for several months.  相似文献   

14.
Arid regions of the world occupy up to 35% of the earth's surface, the basis of various definitions of climatic conditions, vegetation types or potential for food production. Due to their high ecological value, monitoring of arid regions is necessary and modern vegetation studies can help in the conservation and management of these areas. The use of remote sensing for mapping of desert vegetation is difficult due to mixing of the spectral reflectance of bright desert soils with the weak spectral response of sparse vegetation. We studied the vegetation types in the semiarid to arid region of Mond Protected Area, south-west Iran, based on unsupervised classification of the Spot XS bands and then produced updated maps. Sixteen map units covering 12 vegetation types were recognized in the area based on both field works and satellite mapping. Halocnemum strobilaceum and Suaeda fruticosa vegetation types were the dominant types and Ephedra foliata, Salicornia europaea-Suaeda heterophylla vegetation types were the smallest. Vegetation coverage decreased sharply with the increase in salinity towards the coastal areas of the Persian Gulf. The highest vegetation coverage belonged to the riparian vegetation along the Mond River, which represents the northern boundary of the protected area. The location of vegetation types was studied on the separate soil and habitat diversity maps of the study area, which helped in final refinements of the vegetation map produced.  相似文献   

15.
Recent advances in the proteomic field have allowed high-throughput experiments to be conducted on chloroplast samples. Many proteomic investigations have focused on either whole chloroplast or sub-plastidial fractions. To date, the Plant Protein Database (PPDB, Sun et al., 2009) presents the most exhaustive chloroplast proteome available online. However, the accurate localization of many proteins that were identified in different sub-plastidial compartments remains hypothetical. Ferro et al. (2009) went a step further into the knowledge of Arabidopsis thaliana chloroplast proteins with regards to their accurate localization within the chloroplast by using a semi-quantitative proteomic approach known as spectral counting. Their proteomic strategy was based on the accurate mass and time tags (AMT) database approach and they built up AT_CHLORO, a comprehensive chloroplast proteome database with sub-plastidial localization and curated information on envelope proteins. Comparing these two extensive databases, we focus here on about 100 enzymes involved in the synthesis of chloroplast-specific isoprenoids. Well known pathways (i.e. compartmentation of the methyl erythritol phosphate biosynthetic pathway, of tetrapyrroles and chlorophyll biosynthesis and breakdown within chloroplasts) validate the spectral counting-based strategy. The same strategy was then used to identify the precise localization of the biosynthesis of carotenoids and prenylquinones within chloroplasts (i.e. in envelope membranes, stroma, and/or thylakoids) that remains unclear until now.  相似文献   

16.
Impacts of salinity become severe when the soil is deficient in oxygen. OxygaUon (using aerated water for subsurface drip irrigation of crop) could minimize the impact of salinity on plants under oxygen-limiting soil environments. Pot experiments were conducted to evaluate the effects of oxygation (12% air volume/volume of water) on vegetable soybean (moderately salt tolerant) and cotton (salt tolerant) in a salinized vertisol at 2, 8, 14, 20 dS/m ECe. In vegetable soybean, oxygation increased above ground biomass yield and water use efficiency (WUE) by 13% and 22%, respectively, compared with the control. Higher yield with oxygation was accompanied by greater plant height and stem diameter and reduced specific leaf area and leaf Na^+ and CI^- concentrations. In cotton, oxygation increased lint yield and WUE by 18% and 16%, respectively, compared with the control, and was accompanied by greater canopy light interception, plant height and stem diameter. Oxygation also led to a greater rate of photosynthesis, higher relative water content in the leaf, reduced crop water stress index and lower leaf water potential. It did not, however, affect leaf Na^+ or CI^- concentration. Oxygation invariably increased, whereas salinity reduced the K^+: Na^+ ratio in the leaves of both species. Oxygation improved yield and WUE performance of salt tolerant and moderately tolerant crops under saline soil environments, and this may have a significant impact for irrigated agriculture where saline soils pose constraints to crop production.  相似文献   

17.
Survival of wampee (Clausena lansium Skeels) axes and maize (Zea mays L.) embryos decreased with rapid and slow dehydration. Damage of wampee axes by rapid dehydration was much less than by slow dehydration, and that was contrary to maize embryos. The malondialdehyde contents of wampee axes and maize embryos rapidly increased with dehydration, those of wampee axes were lower during rapid dehydration than during slow dehydration, and those of maize embryos were higher during rapid dehydration than during slow dehydration. Activities of superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) of wampee axes markedly increased during the early phase of dehydration, and then rapidly decreased, and those of rapidly dehydrated axes were higher than those of slow dehydrated axes when they were dehydrated to low water contents. Activities of SOD and APX of maize embryos notable decreased with dehydration. There were higher SOD activities and lower APX activities of slowly dehydrated maize embryos compared with rapidly dehydrated maize embryos. CAT activities of maize embryos markedly increased during the early phase of dehydration, and then decreased, and those of slowly dehydrated embryos were higher than those of rapidly dehydrated embryos during the late phase of dehydration.  相似文献   

18.
Responses of the photosynthetic activity of Phaeodactylum tricornutum (Bacillariophyta) to organic carbon glycerol were investigated. The growth rate, photosynthetic pigments, 77 K fluorescence spectra, and chloroplast ultrastructure of P. tricornutum were examined under photoautotrophic, mixotrophic, and photoheterotrophic conditions. The results showed that the specific growth rate was the fastest under mixotrophic conditions. The cell photosynthetic pigment content and values of Chl a/Chl c were reduced under mixotrophic and photoheterotrophic conditions. The value of carotenoid/Chl a was enhanced under mixotrophic conditions, but was decreased under photoheterotrophic conditions. In comparison with photoautotrophic conditions, the fluorescence emission peaks and fluorescence excitation peaks were not shifted. The relative fluorescence of photosystem (PS) Ⅰ and PS Ⅱ and the values of F685/F710 and F685/F738 were decreased. Chloroplast thylakoid pairs were less packed under mixotrophic and photoheterotrophic conditions. There was a strong correlation between degree of chloroplast thylakoid packing and the excitation energy kept in PS Ⅱ. These results suggested that the PS Ⅱ activity was reduced by glycerol under mixotrophic conditions, thereby leading to repression of the photosynthetic activity.  相似文献   

19.
Protein S-glutathionylation, the reversible formation of a mixed-disulfide between glutathione and protein thiols, is involved in protection of protein cysteines from irreversible oxidation, but also in protein redox regulation. Recent studies have implicated S-glutathionylation as a cellular response to oxidative/nitrosative stress, likely playing an important role in signaling. Considering the potential importance of glutathionylation, a number of methods have been developed for identifying proteins undergoing glutathionylation. These methods, ranging from analysis of purified proteins in vitro to large-scale proteomic analyses in vivo, allowed identification of nearly 200 targets in mammals. By contrast, the number of known glutathionylated proteins is more limited in photosynthetic organisms, although they are severely exposed to oxidative stress. The aim of this review is to detail the methods available for identification and analysis of glutathionylated proteins in vivo and in vitro. The advantages and drawbacks of each technique will be discussed as well as their application to photosynthetic organisms. Furthermore, an overview of known glutathionylated proteins in photosynthetic organisms is provided and the physiological importance of this post-translational modification is discussed.  相似文献   

20.
The early evolution of angiosperms has been a focus of intensive research for more than a century. The Yixian Formation in western Liaoning yields one of the earliest angiosperm macrofioras. Despite multitudes of angiosperm fossils uncovered, including Archaefructus and Sinocarpus, no bona fide normal flower has been dated to 125 Ma (mega-annum) or older. Here we report Callianthus dilae gen. et sp. nov. from the Yixian Formation (Early Cretaceous) in western Liaoning, China as the earliest normal flower known to date. The flower demonstrates a typical floral organization, including tepals, androecium, and gynoecium. The tepals are spatulate with parallel veins. The stamens have a slender filament, a globular anther, bristles at the anther apex, and in situ round-triangular pollen grains. The gynoecium is composed of two stylate carpels enclosed in a fleshy envelope, and develops into a "hip" when mature. Since the well-accepted history of angiosperms is not much longer than 125 Ma, Callianthus together with Chaoyangia, Archaefructus and Sinocarpus from the Yixian Formation demonstrate a surprisingly high diversity of angiosperms, implying a history of angiosperms much longer than currently accepted.  相似文献   

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