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1.
系统研究了我国本土两栖动物种黑斑蛙(Rana nigromaculata)变态发育过程中甲状腺组织学和甲状腺激素水平的变化,为甲状腺生物学和甲状腺干扰研究提供基础数据。黑斑蛙蝌蚪发育的形态变化: 第26-40阶段,后腿芽生长并逐渐分化出五趾结构;42阶段,开始进入变态高峰期,前肢展开,尾吸收,蝌蚪身体发生巨大形变;46阶段,蝌蚪完全变态成小蛙。随着形态学的变化,甲状腺的组织结构也发生明显的变化: 26-37阶段,甲状腺体积较小,增长缓慢;38阶段甲状腺体积迅速膨大,进入高峰期,甲状腺的发育达到顶峰;随着变态完成,甲状腺又逐渐缩小。甲状腺组织学变化的同时,甲状腺激素水平也相应发生变化: 在变态前期,下颌中3,3',5-三碘代-L-甲腺原氨酸(T3)水平增长缓慢,进入变态期后,T3含量迅速升高,在变态高峰期达到峰值,随后下降。以上结果表明,黑斑蛙发育过程中甲状腺组织学的变化与甲状腺激素水平的波动相吻合。对黑斑蛙甲状腺系统的研究,可为日后使用黑斑蛙开展甲状腺干扰作用的研究提供基础。    相似文献   

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结缕草(Zoysia japonica)在镉(Cd)污染农田上开发与应用的研究   总被引:6,自引:0,他引:6  
张绵 《植物研究》2002,22(4):467-472
为了对Cd污染农田实施农业生态整治及安全高效利用,将Cd污染土壤作为一种特殊的资源,在Cd污染农田建植绿化草坪繁育基地是近年提出的新方法。Cd污染地各种草坪草富集Cd含量的结果表明,结缕草是对污染地中Cd的摄取富集量最低的草坪品种,进行异地栽植,不会造成二次污染,并改变了土壤层中Cd的浓度构成。通过采用草坪生产模式,消除食物链中Cd的危害,为重金属污染地的生物修复和开发利用探索新的途径。  相似文献   

4.
大豆黄酮对大鼠乳腺发育作用的实验研究   总被引:17,自引:1,他引:17  
张荣庆  韩正康 《动物学报》1995,41(3):332-338
本文研究了大豆黄酮对大鼠乳腺发育及其对垂体生长激素(GH)和催乳素(PRL)分泌的影响,结果表明:1)胃饲或皮下注射大豆黄酮能显著提高去卵巢大鼠或正常处女大鼠乳腺重量和乳腺DNA、RNA含量;2)胃饲或皮下注射大豆黄酮能显著提高正常处女大鼠血清GH和PRL含量,3)大豆黄酮能显著提高大鼠乳腺,垂体和下丘脑胞浆雌二醇受体的数目,并显著提高乳腺孕酮受体的数目,体外受体竞争结合试验结果表明:大豆黄酮与大  相似文献   

5.
槐种子发育中胚乳细胞半乳甘露聚糖积累的研究   总被引:2,自引:0,他引:2  
槐 ( Sophora japonica L.)开花约 60 d至种子成熟 ,为胚乳半乳甘露聚糖积累期。用组织化学方法 ,对储藏于胚乳细胞壁上的半乳甘露聚糖的形成积累进行了观察 ,结果表明 ,半乳甘露聚糖最先在邻近胚的胚乳细胞的粗面内质网的囊泡腔内形成 ,并通过细胞质膜分泌至细胞壁周围。此后 ,半乳甘露聚糖的积累逐渐向种皮方向扩展 ,及至种子成熟时 ,除糊粉层外 ,所有胚乳细胞几乎全由多糖所填充。此外 ,对半乳甘露聚糖发生部位及其积累过程的消长变化进行了讨论  相似文献   

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单套染色体组在泽蛙雌核单倍体发育中的作用   总被引:6,自引:0,他引:6  
本文比较了泽蛙(Rana limnocharis Boie)单倍体和二倍体的胚胎发育。结果表明:泽蛙单倍体的生活力低下,器官发生异常,自原肠胚起发育速度减慢。据此,作者讨论了单套染色体组在个体发育中的作用。  相似文献   

8.
This study was designed to investigate whether the larval development of an anuran amphibian could be modified by raising the animals in continuous light or darkness instead of under conditions of diurnal illumination, and to quantify the effects of these treatments at various intervals during this period of development.
Larvae of the frog, Rana pipiens , were raised through metamorphosis under conditions of constant light, constant darkness, or diurnal lighting. As measured by stages of development, body weight, tail length and body length at 20-day intervals, no significant differences in growth rate or metamorphic change were observed until near the middle of the prometamorphic period, which began at approximately the 50th day of development. After midmetamorphosis, a significant acceleration in the measured parameters was seen for the animals raised in conditions of constant light in comparison with those in constant darkness. Those with diurnal lighting were intermediate.
These results suggested that light, or its absence, can respectively stimulate or retard amphibian metamorphosis in late larval stages after the hypothalamo-hypophyseal-thyroid axis has matured. Neither continuous light nor continuous darkness during larval development prevented the transformation from tadpole to frog.  相似文献   

9.
泽蛙雌核生殖单倍体发育中的核质关系   总被引:2,自引:2,他引:0  
吴仲庆 《动物学研究》1988,9(4):335-342
本文详细比较了由同一母体卵子产生的泽蛙单倍体和二倍体的个体发育,并依据实验结果,讨论了个体发育中的核质关系。作者认为,个体发育始末,细胞质虽然影响早期的发育和细胞分化,但是,细胞核一直起到主导作用。没有正常的染色体组数,就没有正常的细胞分化和个体发育。  相似文献   

10.
When androgenic glands from mature males were implanted into females of Armadillidium vulgare during the 3rd, 4th and 5th instars, oviducts developed in 14.3, 37.9 and 85.2% of the masculinized females, respectively. These results show that development of the rudimentary oviducts is inhibited by the androgenic gland hormone in very young females. Development of the oviduct seems to be determined at a critical period in about the 4th instar and after this, the hormone has little inhibitory effect.  相似文献   

11.
麝鼠香腺发育与活体取香的初步研究   总被引:5,自引:0,他引:5  
根据麝鼠香腺的形态发育,将其划分为非泌香期、香腺发育期、泌香盛期和泌香持续期4个时期.通过对192只成年雄性麝鼠分另进行5次活体取香,每只取香量累计达2.65±0.32g。非泌香期肌注丙酸睾丸素5mg/kg。可诱导雄麝鼠香腺的发育和泌香。通过饲养繁殖观察,证明雄体取香对配偶雌体繁殖无不良影响。  相似文献   

12.
Acrosomal reaction and acrosomal protease release in Leptodactylus chaquensis are correlated. When spermatozoa are included in gelatin films, the characteristic digestion halos around the sperm head can be observed only after the acrosomic reaction is accomplished. The addition of 10 mM EDTA to the gelatin films arrests the acrosomic reaction and no digestion halo is formed. Crude enzymatic preparations containing acrosomal proteases are equally active on gelatin and BAPNA substrates, irrespective of the presence of EDTA. Trypsin inhibitors (ovomucoid, lima bean and soybean) produce both diminution of the digestion halo and lowering of the activity of crude enzymatic preparations on gelatin or BAPNA substrates.  相似文献   

13.
人肾上腺内肽能神经的超微结构   总被引:1,自引:0,他引:1  
应用抗生蛋白链菌素一生物素一过氧化物酶复合物的免疫电镜技术,在相邻切片中,分别观察人肾上腺内NPY、VIP、SP和CGRP免疫反应神经纤维的超微结构和免疫反应物的定位。NPY和VIP免疫反应物位于小颗粒羹泡和线粒体外膜,部分嗜铬细胞呈NPY免疫反应阳性。SP和CGRP免疫反应物主要定位于大颗粒囊泡内。SP和CGRP免疫反应轴突与嗜铬细胞形成对称性或非对称性的轴体突轴。测量了这4种肽能神经末梢的直径,从而推测其来源,并讨论了该4种神经肽对人肾上腺的作用。  相似文献   

14.
The distribution and proportion of the sexual species Rana lessonae to the hemiclonal hybrid R. esculenta among natural habitats suggests that these anurans may differ in adaptive abilities. I used a half-sib design to partition phenotypic and quantitative genetic variation in tadpole responses at two food levels into causal variance components. Rana lessonae displays strong phenotypic variation across food levels. Growth rate is strictly determined by environmental factors and includes weak maternal effects. Larval period and body size at metamorphosis both contain moderate levels of additive genetic variance. The sire x food interactions and the lack of environmental correlations indicate that adaptive phenotypic plasticity is present in both of these traits. In contrast, R. esculenta displays less phenotypic variation across food levels, especially for larval period. Variation in body size at metamorphosis is underlain by genetic variation as shown by high levels of additive genetic variance, yet growth rate and larval period are not. Significant environmental correlations between larval period at high food level and growth, larval period, and body size at low food, indicate phenotypic plasticity is absent. A positive phenotypic correlation between body size at metamorphosis and larval period for R. lessonae at both food levels suggests a trade-off between growing large and metamorphosing quickly to escape predation or pond drying. The lack of a similar correlation for R. esculenta at the high food level suggests it may be less constrained. Different levels of adaptive genetic variation among larval traits suggest that the sexual species and the hybridogenetic hemiclone differ in their abilities to cope with temporally and spatially heterogeneous environments.  相似文献   

15.
水稻中央细胞发育期间超微结构变化的观察   总被引:1,自引:0,他引:1  
本文通过透射电镜对水稻受精前胚囊中央细胞发育过程中超微结构的变化进行观察。结果表明,八核胚囊形成后很快就进行细胞化形成7个细胞,其中刚形成的中央细胞由1个大液泡、2个极核(珠孔端和合点端各1个)和一些含有丰富细胞器的胞质组成。中央细胞以后的发育主要是极核的发育和极核周围胞质的变化。极核发育经历以下过程:a.2个核都膨大呈“椭圆”形。核周围胞质呈不对称分布。b.2个核分别向胚囊中央移动并相互靠近。之后2个极核调整排列方式,由纵排(即与胚囊纵轴平行)变成横排。此时期有细胞质“桥”联结珠孔端卵器、2个极核和合点端反足细胞器。c.横排的极核移向卵器,并排列于卵细胞之上。此时胚囊未明显膨大,但极核相靠近的两边核膜有许多处已形成“融合桥”,核周围的胞质也起较大的变化,如质体内淀粉消失和光面内质网增加等。极核进一步发育直至胚囊成熟期间,极核排列方式及其周围胞质组成未观察到明显的变化,但胚囊体积明显增大。  相似文献   

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Cell surface specialization, a characteristic common to most ion-transporting epithelia, was studied in the salt (nasal) gland of the domestic duck in relation to osmotic stress. Three days after hatching, experimental ducklings were given 1% NaCl to drink for 12 hr and freshwater for the remainder of each day. Control ducklings were maintained exclusively on freshwater. The fine structure of the secretory epithelium was examined on various days of the regimen. The nasal gland epithelium of the secretory lobule is composed of several types of cells. Peripheral cells, lying at the blind ends of the branched secretory tubules, are similar in both control and experimental animals at all stages of glandular development. These generative cells contain few mitochondria and have nearly smooth cell surfaces. Partially specialized secretory cells predominate in the secretory tubules of control animals and appear as transitional cells in the tubular epithelium of salt-stressed animals. These cells contain few mitochondria and bear short folds along their lateral cell surfaces. Fully specialized cells dominate the secretory epithelium of osmotically stressed ducklings. The lateral and basal surfaces of these cells are deeply folded, forming complex intra- and extracellular compartments. This vast increase in absorptive surface area is paralleled by an increase in the number of mitochondria that pack the basal compartments. The development of this fully specialized cell is correlated with the marked increase in (Na+-K+)-ATPase activity in the glands of osmotically stressed birds.  相似文献   

18.
Gene flow is often considered to be one of the main factors that constrains local adaptation in a heterogeneous environment. However, gene flow may also lead to the evolution of phenotypic plasticity. We investigated the effect of gene flow on local adaptation and phenotypic plasticity in development time in island populations of the common frog Rana temporaria which breed in pools that differ in drying regimes. This was done by investigating associations between traits (measured in a common garden experiment) and selective factors (pool drying regimes and gene flow from other populations inhabiting different environments) by regression analyses and by comparing pairwise FST values (obtained from microsatellite analyses) with pairwise QST values. We found that the degree of phenotypic plasticity was positively correlated with gene flow from other populations inhabiting different environments (among‐island environmental heterogeneity), as well as with local environmental heterogeneity within each population. Furthermore, local adaptation, manifested in the correlation between development time and the degree of pool drying on the islands, appears to have been caused by divergent selection pressures. The local adaptation in development time and phenotypic plasticity is quite remarkable, because the populations are young (less than 300 generations) and substantial gene flow is present among islands.  相似文献   

19.
Couch's spadefoot toads (Scaphiopus couchii) breed in ponds of uncertain duration. In natural ponds, larvae exhibit considerable variation in growth, size at metamorphosis, and development time. Phenotypic differences in development time may dramatically affect survivorship in these ponds. A quantitative-genetic analysis of larval traits was undertaken to determine the potential evolutionary relevance of phenotypic variation observed in the field. Additive genetic variance was detected for development time, but not for any other trait. Some variation in early growth was attributed to maternal effects; maternal effects, however, were not apparent for size at metamorphosis or development time. Nonadditive genetic effects were not statistically significant for any trait, but the nonsignificance of these effects must be interpreted cautiously, as the sample of females was relatively small and the mating design used is not very effective for detecting interactions. Genetic variation in development time in this population is most likely maintained by variability in the direction of selection as a consequence of variation in pond duration.  相似文献   

20.
虎纹蛙消化道肥大细胞类胰蛋白酶免疫组化研究   总被引:1,自引:0,他引:1  
研究采用小鼠抗人肥大细胞类胰蛋白酶单克隆抗体AA1,应用ElivisionTM plus免疫组化染色法对虎纹蛙(Rana tigrina rugulosa)消化道组织中类胰蛋白酶阳性肥大细胞存在的可能性进行研究。研究发现单克隆抗体AAl可与中性缓冲福马林液固定的虎纹蛙组织的肥大细胞获得良好的交叉反应,类胰蛋白酶阳性细胞胞浆染成棕黄色,证实虎纹蛙肥大细胞胞浆颗粒中也存在类胰蛋白酶。虎纹蛙组织中AA1免疫染色阳性细胞的分布,与AB/SO和改良甲苯胺兰染色阳性细胞的分布存在较大的差异:虎纹蛙类胰蛋白酶阳性细胞数量很少,且阳性反应比人胃癌间质肥大细胞弱,主要见于黏膜型肥大细胞(MMC)分布区域,如消化道黏膜上皮下方和固有层,少量分布于肠绒毛基底部及食管腺和胃腺周围。而在结缔组织型肥大细胞(CTMC)分布区域,如消化道黏膜下层结缔组织中却未见类胰蛋白酶阳性细胞。AB/SO和改良甲苯胺兰染色阳性细胞数量多,广泛分布于消化道黏膜固有层、黏膜下层、腺体之间、肌间及外膜结缔组织,说明并不是所有的虎纹蛙肥大细胞都含有类胰蛋白酶。很有可能是虎纹蛙MMC中含有类胰蛋白酶,而CTMC中不含类胰蛋白酶。虎纹蛙类胰蛋白酶阳性细胞数量很少,且阳性反应比人胃癌间质肥大细胞弱,说明虎纹蛙肥大细胞胞浆颗粒类胰蛋白酶含量较少,虎纹蛙属于低等脊椎动物,可能与生物进化水平较低有关,有待进一步研究。    相似文献   

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