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性别分化是遗传学、进化生物学和生殖行为生态学研究的重要领域之一,对于研究生物的遗传与进化关系、分析生物种群数量动态具有重要意义。对韭菜迟眼蕈蚊BradysiaodoriphagaYangetZhang的性别分化研究结果表明,韭菜迟眼蕈蚊的生殖对策主要以产单性别方式为主,其次是产优势性别方式,2种方式占92%,且产雌产雄的比例基本呈对称现象。用雌雄试虫都来自单性别的种群,连续繁殖3代,其性别分化如同上述,每一代种群的性比基本保持在1∶1。用双性别后代雌虫所产的雌雄虫进行近亲繁殖,连续繁殖3代,结果表明双性别后代的比例明显增大。鉴于以上实验结果,对韭菜迟眼蕈蚊生殖对策的生态与进化意义进行了分析。 相似文献
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白斑隐蛛(Nurscia albofasciata)的组型分析 总被引:2,自引:0,他引:2
以胚胎细胞为材料,利用滴片和火焰干燥法制备了白班隐蛛的染色体,结果表明:白斑隐蛛的染色体数目,雌蛛2n=32,雄蛛2n=30,性别决定机制为X1X2O型,还从白斑隐蛛在分类学位置讨论了蜘蛛染色体进化的机制。 相似文献
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性染色体进化及性别决定机制是脊椎动物进化研究的热点,近些年更是提出了性别组学的概念。脊椎动物各类群的性别决定机制呈现出多种形式,尤其是具有年青性染色体系统的类群的演化模式更为多样。由于年青性染色体在核型形态上差异不大,传统的研究方法难以识别,因此本文从细胞遗传学方法、性染色体上的DNA序列/RNA序列及其表达、蛋白质表达等多个维度阐述了年青性染色体和性别决定系统的鉴定方法。在高通量测序技术的基础上结合基因组学、蛋白质组学和代谢组学对性别决定系统进行更深层次的研究,从而形成性别组学,并最终解答性别决定的方式多样性及其背后的进化动力和分子途径。 相似文献
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高等植物的性别与性别决定机制 总被引:2,自引:0,他引:2
生物在进化过程中出现了性别,有性繁殖是真核生物繁殖的主要形式,并导致了大多数真核生物两性异型的进化。本简要介绍了植物的性多态现象及雌雄异株植物的性染色体,主要介绍了雌雄异株植物的性别决定系统的三种基本类型,并与动物的性别决定系统作了比较。 相似文献
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早期胚胎的发育选择:性别决定 总被引:2,自引:0,他引:2
性别决定是一个复杂的发育调控过程, 早期胚胎发育过程中, 雌雄二者必居其一的发育选择是胚胎性腺形成必须的发育决定。文章综述了动物性别决定的遗传系统、性腺发生、性别决定关键基因及其作用机制, 从分子进化的角度分析了性染色体与性别决定形成机制, 提示性别决定基因在进化中总是趋向异配性染色体。 相似文献
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In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980. 相似文献
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N. P. Vesselkin Yu. V. Natochin 《Journal of Evolutionary Biochemistry and Physiology》2010,46(6):592-603
Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms.
The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal
mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization
followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The
mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction
of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms
are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning
of physiological systems and organs of the living organism 相似文献