首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 562 毫秒
1.
吴美仙  赵波  张文  陆洪良 《生态学报》2014,34(19):5398-5404
用3个恒定温度(24、26和28℃)孵化黄喉拟水龟南方种群卵,检测孵化温度对孵化期、孵化成功率和孵出幼体特征的影响。孵化温度显著影响孵化期和孵化成功率、以及幼体的性别、大小和早期生长。黄喉拟水龟幼体的性别取决于孵化温度(属TSDⅠa型),26℃和28℃孵出幼体偏雄性,30℃孵出幼体都是雌性。随着孵化温度的升高,孵化期呈非线性缩短,而孵化成功率略微增加。较高温度下孵出的幼体较大且具有较好的功能表现,但生长较慢。低温孵出幼体较小,但胚后生长速率较快。低温孵出幼体较小可能与胚胎发育期长、总代谢消耗大有关;而生长速率快则可能是因为低温产生的雄性幼体生长快于高温产生的雌性幼体。与已报道的黄喉拟水龟北方种群卵孵化结果相比较,26℃和28℃条件下南方种群卵的孵化期和产生1∶1性比的关键温度较大。这种地理上的变异可能反映不同种群对当地热环境适应性上的差异。  相似文献   

2.
杜卫国  计翔 《生态学报》2002,22(4):548-553
用4个恒定温(24-32℃)孵化灰鼠蛇卵,检测温度对孵化期,孵化成功率和孵出幼体特征的影响。在24-32℃范围内,孵化温度显影响孵化期及孵出幼体的体长和剩余卵黄大小,但不影响孵化成功率和孵出幼体的性别,体重,躯干重和脂肪体重。24,26,30和32℃孵化期分别为99.0,72.2,54.7和48.7d。24℃和26℃孵出幼体的体筮大于30℃和32℃孵出幼体;24℃和32℃孵同幼体内的卵黄较多。不同温度下发育的胚胎对卵内物质和能量的利用一定的差异,但差异不显。雌性幼体的体长,尾长和总长均大于雄性幼体,这些两性差异与孵化温度无关。孵出幼体和新生卵内容的灰分含量无显差异,孵化前后卵壳灰分含量也无显差异,表明灰鼠蛇的卵黄可提供胚胎发育所需的所有无机物。  相似文献   

3.
孵化水热环境对渔异色蛇孵化卵和孵出幼体的影响   总被引:10,自引:6,他引:4  
渔异色蛇卵孵化时能从环境中吸收水分导致质量增加,卵质量的增加与初始卵质量和孵化基质湿度有关。较大幅度的孵化基质湿度变化对孵化期、孵化成功率、胚胎动用孵内物质和能量、孵出幼体的性比、大小和质量无显著影响。孵化期随温度升高而缩短,并显示极强的窝间差异。温度对孵出幼体的性别无影响,但显著影响孵化成功率、胚胎对卵内物质和能量的动用、幼体的大小和质量、躯干和剩余卵黄的质量。孵出幼体总长的两性差异不显著,但雌体体长大于雄体而尾长小于雄体。32℃不适于孵化渔异色蛇卵,该温度下孵出的幼体躯干发育不良,剩余孵黄较多,尾部均呈畸形,孵化过程中能量转化率较低。24℃和26℃中孵出的幼体躯干发育良好,孵化过程中能量转化率较高,各项被测定的幼体特征指标均极相似。  相似文献   

4.
对浙江地区3个多疣壁虎(Gekko japonicus)种群的个体大小、繁殖生活史特征进行了测定。在24 ℃、28 ℃和31 ℃条件下,孵化多疣壁虎卵,并测定其孵化期和幼体特征。结果表明:多疣壁虎成体存在显著种群间变异和两性差异,即衢州和温州个体大于杭州个体,雌体大于雄体;卵平均质量和窝卵重无显著种群间差异,但杭州壁虎的相对窝卵重显著大于衢州和温州个体;孵化温度能显著影响孵化期及幼体的尾长和头宽,但不影响幼体体长、体质量及运动能力;孵化温度效应不存在种群间差异。本研究揭示了疣壁虎个体大小、繁殖输出以及卵孵化特征的微地理变异。  相似文献   

5.
蜓头,体大小的两性异形和雌体繁殖   总被引:13,自引:3,他引:10  
计翔  杜卫国 《动物学研究》2000,21(5):349-354
报道了Yan蜓(Sphenomorphus indicus)头、体大小的两性异形和雌性繁殖。性成熟雌体大于雄体。雄性成体头长大于雌性成体,但头宽与雌性成体无显著差异。初生幼仔的头长和头宽无两性差异。雄性幼体头长和头宽大于雌性幼体。设置SVL恒定时,雄性幼体和雄性成体的头长和头宽无显著差异,雌性幼体的头长和头宽大于雌性成体。初生幼仔具有相对较大的头部。产仔雌体的最小SVL为67.7mm,大于此SVL  相似文献   

6.
蓝尾石龙子的生长、两性异形及雌性繁殖   总被引:31,自引:4,他引:27  
杜卫国  计翔 《动物学研究》2001,22(4):279-286
报道蓝尾石龙子(Eumeces elegans)的生长、两性异形和雌性繁殖,性成熟个体体色的两性差异显著,成年雄性体长、头长和头宽显著大于成年雌性,幼体体长生长率无显著的两性差异。成年雄体体长生长率显著大于成年雌体,因此,个体大小的两性异形是性成熟后发生的,体长小于50mm的幼体,头长和头宽无性差异;当体长大于50mm。雄性头长和头宽随体长的生长率显著大于雌性。并导致头部大小的两性异形,并随个体发育变得越来越显著,蓝尾石龙子产卵雌体的最小体长为69.3mm,大于此体长的雌体均年产单窝卵。窝卵数、窝卵重和平均卵重均与雌体体长呈正相关,平均值分别为6.4、2.783和0.554g。窝卵数与雌体产后状态无关,蓝尾石龙子雌体主要通过增加窝卵数和卵大小来增加繁殖输出。  相似文献   

7.
孵化温度对白条草蜥孵出幼体大小、形态和运动表现的影响   总被引:11,自引:1,他引:11  
潘志崇  计翔 《生态学报》2001,21(12):2031-2038
实验用白条草蜥(Takydrous wolteri)卵由1999年和2000年4月捕自安徽滁州的19条成年雌体产出。用4个恒定温度(24-33℃)孵化白条草蜥卵,检测孵化温度对孵出幼体大小、形态和运动表现的影响。孵化卵从环境中吸不导致生量增加,卵重量增加与卵初始重量和孵化温度有关。24、27、30和33℃孵化期的平均值分别为41.9、30.6、6.25和22.6d。温度显著影响孵化成功率及孵出幼体的湿重、躯干干重和剩余卵黄干重,但对孵出幼体的性别、体长、尾长和干重无显著影响。24℃和27℃孵出幼体湿重和躯干干重大于33℃孵出幼体,剩余卵黄干则小于33℃孵出幼体;30℃和33℃孵出幼体的湿重、躯干干重和剩余卵黄干重无显著差异。孵化温度显著影响孵出幼体一些局部形态特征:24℃和27℃孵出幼体头长和头宽矫正值显著大于高温(33℃)孵出幼体,24℃孵出幼体耳径正值一般小于较高温度孵出的幼体。疾跑速与幼体体长成正相关,与幼体尾长和状态无关。高温孵出幼体运动能力较差。雄笥幼体腹鳞行数少于雌性幼体,尾长和后肢长大于雌性幼体,这些特征的两性差异与孵化温度无关。孵化热环境能诱导白条草蜥部分表型特征的变异,这些特征的变异可能对个体的适应性具有长期的影响。  相似文献   

8.
近几十年来,发现很多爬行动物具有温度依赖型性别决定机制(TSD),即性别分化取决于胚胎发育过程中温度敏感期(TSP)的环境温度高低.龟鳖类存在两种TSD模式,即低温产雄性、高温产雌性的TSD Ⅰ a,低温、高温均产雌性而中间温度产雄性的TSDⅡ.TSD机制在生理水平的作用机制主要受到性腺类固醇激素的控制,温度通过影响芳香化酶和5α-还原酶的活性控制雌、雄激素转化,进而决定了个体的性别分化.在分子水平的研究发现:Sf1、Mis、Sox9、Dax1、Wt1和Dmrt1等基因的表达受到温度的影响,参与了龟鳖类性别分化.介绍了关于TSD的进化意义提出的假说,有待进一步验证.  相似文献   

9.
陈慧丽  计翔 《生态学报》2002,22(11):1852-1858
用恒温(24、27、30和33C)和波动温度(平均26.1C,范围20.1—32.7C)孵化虎斑颈槽蛇(Rhabdophis tigrinus lateralis)卵,检测热环境对孵化期、孵化成功率和孵出幼体的影响。孵化热环境显著影响孵化期、孵化成功率和胚胎畸形率,对孵出幼体性别无显著影响。孵化期随孵化温度升高而缩短,24、27、30和33C的平均孵化期分别为45.0、32.7、27.3和26.0d,波动温度的平均孵化期为37.9d。33C孵化成功率最低(16.7%),胚胎畸形率最高(100%)。孵出幼体总性比(雌性/雄性=0.6)不显著偏离1:1。孵出幼体的尾长显示两性异形,雄性尾长大于雌性;其它被检幼体特征无显著的两性差异。24、27和30C以及波动温度孵出幼体的所有被检指标均无显著差异。33C孵出幼体的体重和个体大小小于其它热环境中孵出的幼体,并特征性地具有较小的躯干、较大的剩余卵黄。33C中胚胎发育的能耗显著大于其它热环境中胚胎发育的能耗。33(‘孵出幼体的灰分含量较低,但孵出卵卵壳较重。33C孵出幼体不能运动;其它热环境中孵出的幼体在跑道上表现良好,这些幼体的不问断运动的最大距离、每分钟运动距离和每分钟停顿次数无显著的差异。结果表明,持续将虎斑颈槽蛇卵暴露在33C条件下不利于该种胚胎发育并可能对胚胎具有致死性影响,波动温度孵卵有利于拓宽存活孵化温度范围。  相似文献   

10.
计翔  杜卫国 《动物学研究》2000,21(5):349-354
报道了yan蜓(Sphenomorphus indicus)头、体大小的两性异形和雌性繁殖。性成熟雌体大于雄体。雄性成体头长大于雌性成体,但头宽与雌性成体无显著差异。初生幼仔的头长和头宽无两性差异。雄性幼体头长和头宽大于雌性幼体。设置SVL恒定时,雄性幼体和雄性成 体的头长和头宽无显著差异,雌性幼体的头长和头宽大于雌性成体。初生幼仔具有相对较大的头部。产仔雌体的最小SVL为67.7 mm,大于此SVL的雌体均年产单窝仔。平均窝仔数、窝仔重和幼仔重分别为7.2(3-11)、3.34(1.30-5.19)和0.48(0.36-0.58)g。用卵黄沉积卵巢卵和输卵管计数的窝仔数比用幼仔计数的窝仔数多约1.0个后代。幼仔体重与雌体SVL无关。相对窝仔重与雌体SVL边缘性地呈正相关。窝仔数、窝仔重与雌体SVL呈正相关,幼仔体重与窝仔数呈负相关。窝仔数与雌体状态无关。  相似文献   

11.
《环境昆虫学报》2014,(5):790-804
综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生(宾主共栖和异种共栖)、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌(原生动物、细菌、真菌和放线菌)和外生菌(蚁巢伞菌等)间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用(如纤维素酶)及今后研究物种间的协同进化提供了基础资料。  相似文献   

12.
New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn2NPSCH2CH2Sa(P-Sa) (Bn = benzyl, 4), Bn2NPSCHCHSa(CH2)3CaH2(P-Sa)(Ca-Sa) (6) and Bn2NP(4-XC6H4OMe)2 (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)2] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl2Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the νCO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The 1JPRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the 1JPSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh3. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh3.  相似文献   

13.
Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.  相似文献   

14.
The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.  相似文献   

15.
To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.  相似文献   

16.
17.
18.
The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE2, PGD2, PGF, TXB2 and 6-keto-PGF. In all types studied PGE2 and TXB2 were the major products formed. The identification of PGE2 and TXB2 was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.  相似文献   

19.
Allergic asthma can be precipitated by many factors. For the atopic person, fungus, pollen, dust mites, cockroach antigens, and diesel exhaust are all agents that may trigger an allergic attack. Cytokines and chemokines are integral mediators of fungal asthma. From the earliest time points, they recruit and activate the cells required for the clearance of fungus as well as being critical factors involved in the immunopathology of this disease. In the final analysis, it is clear that these mediators can act to the benefit or the detriment of the host.  相似文献   

20.
In spite of the many studies on protein modifications by reactive species, knowledge about the products resulting from the oxidation of protein-aromatic residues, including protein-derived radicals and their stable products, remains limited. Here, we compared the oxidative modifications promoted by peroxynitrite and myeloperoxidase/hydrogen peroxide/nitrite in two model proteins, ribonuclease (6Tyr) and lysozyme (3Tyr/6Trp). The formation of protein-derived radicals and products was higher at pH 5.4 and 7.4 for myeloperoxidase and peroxynitrite, respectively. The main product was 3-nitro-Tyr for both proteins and oxidants. Lysozyme rendered similar yields of nitro-Trp, particularly when oxidized by peroxynitrite. Hydroxylated and dimerized products of Trp and Tyr were also produced, but in lower yields. Localization of the main modified residues indicates that peroxynitrite decomposes to radicals within the proteins behaving less specifically than myeloperoxidase. Nitrogen dioxide is emphasized as an important protein modifier.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号