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41.
为探究不同社会地位的亚成体克氏原螯虾(Procambarus clarkii)对利益的分配,以及对社会环境改变(体型较大的入侵同类)各自做出的行为反应,本文统计已确立等级序列的成对同性别螯虾对隐蔽所的占有情况,并视频拍摄同性别螯虾入侵时,入侵者及不同地位的原居者的格斗行为,分析格斗次数、格斗时间、首次攻击及被首次攻击对象多个参数。在隐蔽所占有实验中,71%为优势者占有隐蔽所,7%为从属者占有,共同占有或没有占有的各11%。在入侵-反入侵实验中,雄性入侵者对2只原居虾之间的攻击选择无显著差异,雌性入侵者首次攻击显著选择与原优势者格斗;雄性原居者中优势者对入侵者和原从属者的攻击无显著差异,雌性优势者则显著选择与入侵者格斗;雄性原居者中从属者显著选择与入侵者格斗,雌性从属者对入侵者和原优势者的攻击无显著差异。上述结果表明,优势者优先占有资源;雌雄螯虾在入侵和面临入侵时有各自不同的策略;不同地位的螯虾在反入侵时行为反应也各有不同。 相似文献
42.
断尾对胎生蜥蜴运动能力和选择体温的影响 总被引:1,自引:0,他引:1
尾自切是蜥蜴为了降低被捕食危险而采取的一种反捕食适应策略,但断尾可导致体重减轻、热量收支平衡改变,并影响蜥蜴的运动能力和体温调节.为检验断尾对蜥蜴运动能力和选择体温的影响,于2006年5月选取黑龙江省小兴安岭地区的一个胎生蜥蜴种群进行实验.结果表明:在30 ℃和24℃两个实验温度下,断尾后胎生蜥蜴的运动能力均明显下降,表现在停顿次数增多、最大可持续距离和最大疾跑速度减少等方面;断尾、温度和性别对胎生蜥蝎运动能力的影响在一定程度上是相互独立的,断尾是影响胎生蜥蜴运动能力的主要因素;断尾对胎生蜥蝎的选择体温没有显著影响. 相似文献
43.
《现代生物医学进展》2011,(10):2003
日前一国际研究小组发表在《自然》杂志上的报告称,是人大脑中的neuropsin蛋白活性决定了应激行为的模式,该蛋白信号通路让某些人在压力面前更显脆弱。 相似文献
44.
Identification of immunodominant Th1-type T cell epitopes from Schistosoma japonicum 28 kDa glutathione-S-transferase, a vaccine candidate 总被引:1,自引:0,他引:1
Li GF Wang Y Zhang ZS Wang XJ Ji MJ Zhu X Liu F Cai XP Wu HW Wu GL 《Acta biochimica et biophysica Sinica》2005,37(11):751-758
Th1-type cytokines produced by the stimulation of Th 1-type epitopes derived from defined schistosome-associated antigens are correlated with the development of resistance to the parasite infection. Schistosoma mansoni 28 kDa glutathione-S-transferase (Sm28GST), a major detoxification enzyme, has been recognized as a vaccine candidate and a phase II clinical trial has been carried out. Sheep immunized with recombinant Schistosoma japonicum 28GST (Sj28GST) have shown immune protection against the parasite infection. In the present study, six candidate peptides (P1, P2, P3, P4, P7 and P8) from Sj28GST were predicted, using software, to be T cell epitopes, and peptides P5 and P6 were designed by extending five amino acids at the N-terminal and C-terminal of P1, respectively. The peptide 190-211 aa in Sj28GST corresponding to the Th1-type epitope (190-211 aa) identified from Sm28GST was selected and named P9. The nine candidate peptides were synthesized or produced as the fusion protein with thioredoxin in the pET32c(+)/BL21(DE3) system. Their capacity to induce a Th1-type response in vitro was measured using lymphocyte proliferation, cytokine detection experiments and flow cytometry. The results showed that P6 (73-86 aa) generated the strongest stimulation effect on T cells among the nine candidate peptides, and drove the highest level of IFN-γ, and IL-2. Therefore, P6 is a functional Thl-type T cell epitope that is different from that in Sm28GST, and will be useful for the development of effective vaccines which can trigger acquired immunity against S. japonicum. Moreover, our strategy of identifying the Thl-type epitope by a combination of software prediction and experimental confirmation provides a convenient and cost-saving alternative approach to previous methods. 相似文献
45.
ARNOLD DE LOOF 《Insect Science》2006,13(5):325-338
The paradigm, still around in textbooks, that 'in insects sex is strictly genetic, thus that they do not have sex hormones', is mainly based on a wrong interpretation of the 'gynandromorph argument'. It is no longer tenable. Given the fact that vertebrates and invertebrates probably had a common, sexually reproducing ancestor, there is no reason to assume that only vertebrates need sex hormones. The major function of sex hormones is to inform the somatoplasm about developmental changes that take place in the gonads. In contrast to juvenile hormone and neuropeptides, ecdysteroids meet all criteria to act as sex hormones, which was probably their ancient role. Their much better documented role in moulting and metamorphosis was a secondary acquisition that enabled arthropods to cope with growth problems, imposed by a rigid cuticle. Female insects use 20-hydroxyecdysone (20E), secreted by the follicle cells of the ovary, in a similar way as females of egg-laying vertebrates use estrogens. For a variety of reasons, the possibility that ecdysteroids, in particular ecdysone (E), might also act as sex hormones in male insects, thus as the counterpart of testosterone of vertebrates, has been very much overlooked. Thanks to the recent discovery of the molecular basis of the haploid-diploid system of sex determination in the honeybee, the characterization of Halloween genes, proteomics, RNAi and so on, it now becomes possible to verify whether in insects, as with vertebrates, males are the endocrinologically default gender form. 相似文献
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