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1.
布鲁斯效应是一种由陌生雄性以及其化学信号所引起的妊娠终止现象,首次在实验室小鼠(Musmusculus)中发现。学者们对这一现象进行了多角度、多层次的探索,从行为到内分泌,从神经机理到进化意义,都有相关的研究报道。研究热点主要集中在:布鲁斯效应在其他啮齿类物种中的情况,其生物学意义及神经内分泌机制,有效诱发雌鼠妊娠终止的化学信号成分等几个方面。本文就目前对布鲁斯效应已经取得的一些研究进展进行了回顾,并讨论了未来可能的研究趋势。  相似文献   

2.
金色中仓鼠幼鼠可以利用可听声和超声信号与母鼠进行交流,这些声音可以反映个体的寒冷、饥饿、疼痛等不同生理状态和需求。因疼痛诱发的叫声对于维持幼鼠的存活也有着重要意义。本实验通过录制人为疼痛刺激下,不同日龄金色中仓鼠的叫声,分析并比较了5 - 30 日龄金色中仓鼠不同发声信号特征(可听声出现频次、可听声持续时程、可听声主频率、超声出现频次、超声持续时程、超声主频率)的性别差异;同时记录了幼鼠的两种发声随日龄的变化趋势。结果发现:幼鼠两种叫声的各种参数均未表现性二型现象。幼鼠超声发生频次随日龄增加而逐渐减少。而可听声却正相反,随日龄增加而逐渐上升,并在20 日龄时达到最高峰,之后逐渐下降。可听声持续时程也随日龄而增加。综上,在人为疼痛刺激下,随着日龄增加,幼鼠更倾向于使用可听 声而非超声与母兽进行交流。  相似文献   

3.
王希朝  段恩奎 《动物学报》2005,51(6):1067-1072
除了马属动物外,种间妊娠的胚胎总在妊娠的一定时期流产。以往的研究多集中在宏观结构和解剖学差别的研究上,对于这种现象产生的分子机制却少有报道。为了从信号分子角度阐明种间妊娠维持失败的可能原因,我们通过免疫组化和明胶酶谱法比较了科间和同种妊娠部位整合素αvβ3、FAK、p-ERK、IGFⅡ、IGFBP-1、Shc、PTEN和MMP-2、-9表达的差异。科间妊娠是将金色中仓鼠(Mesocricetus auratus)的胚胎移植入假孕小鼠(Mus musculus)子宫并取妊娠D4、D8、D12的子宫为实验材料,相应时间同种小鼠胚胎移植小鼠妊娠后的子宫和假孕小鼠子宫分别为阳性和阴性对照。免疫组化结果表明D8时,科间妊娠孕体integrinαvβ3、IGF-Ⅱ、IGFBP-1、PTEN、Shc、FAK的表达强度均与正常同种妊娠有差异。而妊娠D8时同种、科间妊娠子宫p-ERK的表达部位与表达量无明显差异。明胶酶谱显示,科间妊娠时MMP-2,-9的分泌模式与同种妊娠明显不同。这些结果表明,上述信号通路分子的差异表达有可能是造成科间妊娠时母胎界面异常的组织学表现的一个原因。  相似文献   

4.
以往对化学通讯在啮齿类社群生活中的作用开展了很多研究,而对视觉信号的作用则很少涉及.本文借助一个特殊设计的透明密封玻璃缸,研究怀孕雌性金仓鼠是否对陌生雄鼠的视觉信号刺激产生应激反应.结果发现实验组和对照组雌鼠在交配后至分娩、分娩至断乳期的体重变化、产仔数量、幼鼠体重变化、睁眼时间、存活率和性比等均未表现显著性差异,而实验组雌鼠正常分娩率显著低于对照组.怀孕雌鼠对陌生雄鼠单一视觉刺激信号产生应激反应的假设得到部分支持.我们的结果表明,陌生雄鼠的视觉信号刺激影响了怀孕雌鼠的繁殖,但该影响并未延伸到分娩后和后代的生长发育.  相似文献   

5.
马爱团  陈耀星  王子旭 《动物学报》2007,53(6):1076-1082
为研究环境雌激素己烯雌酚(DES)的生殖毒性与活性氧(ROS)的关系,连续7天给成年金色中仓鼠皮下注射0、0.01、0.1、1mg/kgBWDES,称量睾丸重量、计算睾丸相对重量,光镜观察睾丸组织结构的变化,分光光度法检测睾丸组织和血浆中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、总抗氧化能力(T-AOC)和丙二醛(MDA)的含量。结果表明:1mg/kgBWDES导致睾丸萎缩、重量下降,曲细精管中生精细胞排列紊乱,管腔内几乎没有成熟精子;随着DES剂量的增加,睾丸组织中SOD、GSH-Px和T-AOC含量显著下降,MDA显著上升。提示DES的生殖毒性与ROS密切相关,DES通过降低抗氧化酶水平,增加ROS含量,干扰生精细胞正常功能,导致细胞死亡,表明氧化损伤可能是环境雌激素生殖毒性的作用机理之一。  相似文献   

6.
人类活动产生的噪声污染对动物和人类的影响正受到日益增多的关注。本文以雄性成年金色中仓鼠为实验动物模型,探讨了北京市主干道交通噪声对其焦虑行为及血象、应激生理的影响。分别以北京主干道噪声(80±10 dB SPL)暴露为实验组,实验室环境噪声(50±4 dB SPL)暴露为对照组,噪声处理动物1小时后进行旷场行为学测试,然后取血对比观测两组鼠血液学指标和应激响应、抗氧化酶活性等生理指标的变化。结果显示道路交通噪声没有导致仓鼠出现明显的焦虑行为;不过,实验组血小板数显著低于对照组(P = 0.044),其他血象指标两组间差异不显著;噪声对血清皮质醇,谷丙、谷草转氨酶影响不显著;实验组的血清谷胱甘肽过氧化物酶(GSH-Px)活性极显著低于对照组(P < 0.001),但超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性、总抗氧化能力 (TAOC) 和丙二醛(MDA)水平两组间差异不显著;血清溶菌酶活性实验组降低较明显,接近显著水平(P = 0.0507)。我们的结果显示道路交通噪声胁迫导致了金色中仓鼠血象指标发生了变化,这提示北京市主干道交通噪声刺激对金色中仓鼠生理功能产生了一定的副作用。  相似文献   

7.
本文记述了在内蒙古中渐新统中发现的仓鼠化石三属四种 Cricetops minor 新种, Cricetops dormitor, Eucricetodon caducus 和 Selenomys mimicus.这是中渐新世仓鼠化石在我国的首次发现.它肯定了三盛公地区产该化石的地层时代为中渐新世;进一步证明了 Selenomys 不是 aplodontid,而是 cricetid,应归入 Cricet■dae 科.  相似文献   

8.
报道了产自贝加尔湖区中中新世Aya洞穴的戈壁古仓鼠(Gobicricetodon)一新种G.filippovisp.nov.。该种以较小的个体和牙齿上的一些原始特征区别于该属其他种类。先前的研究认为Gobicricetodon与近古仓鼠(Plesiodipus)同属于戈壁古仓鼠亚科,然而,它们与欧亚大陆一些置于古仓鼠亚科(Cricetodontinae)内的属在牙齿形态上的高度相似性表明其亲缘关系。为了理清Gobicricetodon和Plesiodipus与Cricetodontinae之间的系统发育关系,也为了阐明这一类群属和属以上级别的分类,使用Mesquite2.72软件作了分支系统学分析。结果获得了3个主要的分支类群,Gobicricetodon,Plesiodipus,Mixocricetodon和Tsaganocricetus同属于其中的一个分支。令人惊奇的是,一些欧洲古仓鼠(Cricetodon)的种,包括其模式种C.sansaniensis也在这一分支内。此外,支序分析还显示上述类群可能起源于欧亚大陆西部的Cricetodon支系。分析的另一项结果指示,Cricetodon属显然是一个多系类群,需要进一步划分为多个属。  相似文献   

9.
描述了产自内蒙古二连盆地呼和勃尔和剖面伊尔丁曼哈组底部砂岩中的3种仓鼠类化石:内蒙古祖仓鼠(新种)Pappocricetodon neimongolensis sp.nov.,中条祖仓鼠(相似种)Pappocricetodon cf.P. zhongtiaensis和祖仓鼠(未定种)Pappocricetodon sp.。P.neimongolensis的特征是有P4或者DP4;M1前附尖细小,前叶小,原尖前棱通常至原小尖横向延伸,再转向前颊侧与前附尖相连,无原尖后棱,原小尖与前尖通过前脊相连;M2原尖后棱较为发育;M3次尖不退化;m1下后尖比下原尖位置靠前;m2下原尖后棱完整,连接下后尖或直达下后尖基部;m3不退化,下外脊S型。新种形态与早期仓鼠类Pappocricetodon antiquus接近,但又略显原始。同时,在该层位还出现有M1前叶已经增大的Pappocricetodon sp.和中脊发育的Pappocricetodon cf.P.zhongtiaensis,表明当时仓鼠类已出现多样化,其起源可能要早于中始新世的伊尔丁曼哈期。  相似文献   

10.
川中丘陵区人工柏木防护林适宜林分结构及水文效应   总被引:1,自引:0,他引:1  
川中丘陵区是长江上游水土流失最严重地区之一,该区大面积柏木防护林林分结构不合理、天然更新不良、林分稳定性差、产品产量和水土保持功能低,急需进行结构调整。通过48个典型柏木纯林样地林分郁闭度与灌木、草本及枯落物盖度和生物量分析,提出了该区人工柏木防护林适宜林分郁闭度为0.6—0.7。根据林分结构,将柏木纯林林分结构划分为5种类型。对比分析结果表明:(1)5种林分类型枯落物最大持水量取决于林分枯落物存贮量,适宜结构型林分与其它4种林分类型枯落物最大持水量存在显著差异,排序结果为适宜结构型(4.038±0.497)t/hm2>中低密度型(3.583±0.521)t/hm2>中高密度型(3.243±0.455)t/hm2>低密度型(2.841±0.656)t/hm2>过密型(2.272±0.580)t/hm2。(2)土壤饱和贮水量排序为适宜结构型(180.59±14.83)mm>中低密度型(173.84±18.06)mm>中高密度型(169.27±13.20)mm>低密度型(162.57±8.79)mm>过密型(150.77±5.08)mm,适宜结构型林分与其余4种林分之间均存在显著差异。(3)6次典型降雨产沙量排序为适宜结构型(360.07 kg/hm2)<中低密度型(577.08 kg/hm2)<中高密度型(625.98 kg/hm2)<低密度型(878.51 kg/hm2)<过密型(1026.74 kg/hm2),5种柏木林分类型产沙量之间均存在显著或极显著差异。  相似文献   

11.
Summary Synaptic ribbons, functionally enigmatic structures of mammalian pinealocytes, were studied during the postnatal development of the pineal gland in the golden hamster (Mesocricetus auratus). On day 4 post partum, synaptic ribbons appear in cells that have already started to differentiate into pinealocytes. Between days 4 and 9, an increase in the number of synaptic ribbons occurs, concomitant with the continuing differentiation of the pineal tissue. Between days 9 and 16, when differentiation of this tissue is almost completed, the number of synaptic ribbons decreases and approaches that characteristic of the adult pineal gland. During development, the synaptic ribbons increase in length, and dense core vesicles are frequently found in the vicinity of these structures. It is assumed that a functional relationship exists between dense core vesicles and the synaptic ribbons, which are considered to be engaged in a certain form of secretory activity of the mammalian pineal gland.Supported by the Deutsche Forschungsgemeinschaft  相似文献   

12.
Ten polymorphic microsatellites were developed for the golden hamster (Mesocricetus auratus), a widely used model organism in biological and medical researches. All loci were used to analyse the microsatellite variability in wild golden hamsters from Syria and in a sample of domestic animals comprising different strains. Average mean expected heterozygosity (HE) and mean allele number (A) of domestic hamsters measured 0.279 ± 0.058 and 2.6 ± 0.306, respectively, compared to 0.809 ± 0.019 and 8.3 ± 1.075 found for wild hamsters. Cross‐species application in other Mesocricetus species proved conservation of most loci throughout the genus.  相似文献   

13.
Summary Neurons projecting from the brain to the pineal gland via the pineal stalk were investigated in the golden hamster with the use of the retrograde horseradish-peroxidase tracing method both in vivo and in vitro. Labelled perikarya were observed in the medial and lateral habenular nuclei as well as in the posterior commissure. Single cells located in the ependymal lining of the pineal- and suprapineal recesses were also retrogradely labelled. These results show that a distinct central innervation of the pineal gland exists in the golden hamster, in agreement with findings in other mammalian species investigated by means of a similar methodology. In addition, also direct signals from the cerebrospinal fluid to the parenchyma might be conducted via cells located within the ependymal layer of the pineal- and suprapineal recesses.This study was supported by grants from the Deutscher Akademischer Austauschdienst to M.M. (312/dk-4-is), the Deutsche Forschungsgemeinschaft to H.W.K. (Ko 758/2-2, 2-3), and the Carlsberg Foundation  相似文献   

14.
The number of cells in the S-phase fraction of the cell cycle reflects proliferative activity. Using flow cytometry histograms and the Phoenix M+ cell cycle program, the percent of cells in the S-phase fraction was measured in single cell suspensions prepared from testes of hamsters of different ages. A cyclical pattern with a period of 9 days, superimposed on another rhythm with a 38 day period was observed (p < 0.01) during hamster maturation and it disappeared after the second spermatogenic wave, where the S phase values reached a plateau. It was concluded that maturing animals passed through a stage in which testicular biological rhythm was involved. Therefore it was concluded that it takes approximately two spermatogenic waves before the proliferation rate in the testis reached a steady state.  相似文献   

15.
Summary Golden hamsters raised at 22°C were adapted in the early summer for 3 weeks to either 28°C or 5°C. To achieve profound changes the photoperiod was also shortened from 14 h to 11 h during adaptation to cold. During the investigation body weight, food consumption, water intake, urine production, and osmolality, as well as secreted amounts of noradrenaline (NA) and dopamine (DA), were recorded in each animal before, during, and after the adaptation period. In another group of golden hamsters the brains were processed for immunocytochemical detection of arginine-vasopressin (AVP) and corticotropin releasing factor (CRF) in the third week of adaptation to a cold or warm environment. In warm-adapted animals food and water consumption and urine production remained unchanged or were only slightly reduced. NA and DA secretion were reduced by 50%. The AVP-immunoreactivity reflected an antidiuretic state in these animals. In fibers influencing the adrenal axis, AVP-immunoreactivity was weak compared to CRF fibers. Food and water consumption, urine production, and DA secretion increased two-fold during cold adaptation. Daily secreted amounts of NA increased nine-fold. AVP-immunoreactivity was weak in projections to the neurohypophysis. Fibers influencing the adrenal axis, however, displayed strong AVP-immunoreactivity in comparison to that of CRF. The immunocytochemically determined patterns of AVP and CRF distribution indicated an activation of the osmoregulative axis in the warm-adapted animals and of the adrenal axis in the cold-adapted golden hamsters.Abbreviations NA noradrenaline - DA dopamine - AVP argininevasopressin - CRF corticotropin releasing factor - SON supraoptic nucleus  相似文献   

16.
Summary Serotonin-like immunoreactivity was investigated in the pineal complex of the golden hamster by use of the indirect immunohistochemical technique. The superficial and deep portions of the pineal gland, and also the pineal stalk exhibited an intense cellular immunoreaction for serotonin. In addition, perivascular serotonin-immunoreactive nerve fibers were observed. Some serotonin-immunoreactive processes of the pinealocytes terminated on the surface of the ventricular lumen in the pineal and suprapineal recesses, indicating a receptive or secretory function of these cells. Several serotonin-immunoreactive processes connected the deep pineal with the habenular area. One week after bilateral removal of both superior cervical ganglia the serotonin immunoreaction of the entire pineal complex was greatly decreased. However, some cells in the pineal complex, of which several exhibited a neuron-like morphology, remained intensively stained after ganglionectomy. This indicates that the indoleamine content of some cells in the pineal complex of the golden hamster is independent of the sympathetic innervation.Supported by a Grant from the Italian Society for Veterinary Sciences  相似文献   

17.
Predictors of dominance in the male golden hamster (Mesocricetus auratus)   总被引:3,自引:0,他引:3  
The outcome of social interactions between four male hamsters was significantly related to body weight (rs=0·66) and to the size and pigmentation of their lateral flank glands (rs=0·82). Weight was held constant in a second experiment and variations in gland size and pigmentation remained significantly related to the outcome of social encounters (rs=0·77). In a third experiment, castrate hamsters of uniform weight receiving either no hormone, 0·1 mg, 0·50 mg, or 1·00 mg testosterone propionate exhibited flank gland variations significantly related to social rank (rs=0·81). These experiments demonstrate that the state of the flank gland, which is related to endogenous androgen levels, can be used as a predictor of social rank in male hamsters.  相似文献   

18.
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