Introduction to Diapause
Introduction to Diapause
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DOI：
10.1007/978-1-4020-5680-2_1
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
V. Alekseev;O. Ravera;B. Stasio
中科院分区：
文献类型：
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作者：
V. Alekseev;O. Ravera;B. Stasio
在高纬度和中纬度地区，有时在热带地区，来自淡水和咸水的生物栖息在具有异质性的环境中。这种不均匀性有不同程度的表现，主要是由太阳辐射的年周期决定的。生物体通过调整其生命周期来适应生物和非生物因素的周期性波动。这可以从繁殖和人口增长时期向一年中特定时期的调整以及这些过程在不利时期的延迟中看出。生物体的生命周期由活跃繁殖和种群增长的时期组成，与这些过程延迟或基本停止的时期交替出现。这种生理休息状态传统上被称为休眠（Keilin 1959）。但如此广泛的定义包括几种密切相关的抑郁状态，如静止、滞育，甚至睡眠。为了进一步理解这种现象，限制滞育一词的使用来描述对环境季节性异质性的适应是有帮助的。这种适应的第一部分与滞育的持续时间有关。众所周知，一些生理和生化过程（例如流动性、营养、蛋白质合成）具有短期抑制，通常与白天长度相称。哺乳动物的睡眠就是这种特征的一个众所周知的例子。相比之下，滞育是一种适应，其持续时间接近或超过生物体生命活跃部分的持续时间。对于生活在干旱地区临时盆地的人群来说，这种情况可能会持续数周到数年，而在湖泊沉积物等其他环境中，这种情况可能会持续数十年甚至数百年（Danilevsky 1961；Hairston et al. 1999a）。这一生活史特征的第二部分涉及滞育“深度”的强度，这是由基础系统的变化引起的，包括神经体液变化、细胞内转化和基因表达（Crag & Denlinger 2000；Gerisch & Antebi 2004；Zhang et al. 1992）。荷尔蒙的分泌和能量储备的积累都需要时间来完成。因此，很明显，滞育并不是对条件简单恶化的立即反应，而是在这种恶化之前发生。此外，环境条件的迅速改善并不能引发滞育的终止。这是滞育和静止之间的主要区别，滞育实际上在抑制因素（例如温度）发生变化后立即开始或结束。明确区分滞育、睡眠和静止的必要性不应排除对它们之间的关系和遗传相似性的理解。
At high and moderate latitudes, and sometimes in the tropics, organisms from fresh and brackish waters inhabit environments that are characterized by heterogeneity. This heterogeneity has different degrees of manifestation and is mainly determined by the annual cycle of solar radiation. Organisms adapt through adjustments of their life cycle to periodical fluctuations of biotic and abiotic factors. This is seen in shifts in the tuning of periods of reproduction and population growth to specific periods of the year, and in a delay of these processes during unfavorable periods. The life cycle of an organism consists of periods of active reproduction and population growth, alternating with periods during which these processes are delayed or essentially stop. This state of physiological rest has traditionally been called dormancy (Keilin 1959). But such a broad definition includes several closely related depressive states such as quiescence, diapause, and even sleep. To further our understanding of this phenomenon it is helpful to restrict usage of the term diapause to describe an adaptation to seasonal heterogeneity of environments. The first part of this adaptation is connected with the duration of the diapause. It is known that some physiological and biochemical processes (eg mobility, nutrition, synthesis of proteins) have short-term depressions, often commensurate with day length. Sleep in mammals is a well-known example of this sort of feature. Diapause, in contrast, is an adaptation that occupies a period approaching or exceeding the duration of the active part of the organism’s lifetime. It may last from weeks to years, as in the case for populations living in temporary basins in arid zones, to decades and hundreds of years in other environments such as lake sediments (Danilevsky 1961; Hairston et al. 1999a). The second part of this life history feature concerns the intensity of “depth” of diapause, which is caused by changes in underlying systems, involving neurohumoral changes, intracellular transformations, and gene expression (Crag & Denlinger 2000; Gerisch & Antebi 2004; Zhang et al. 1992). The secretion of hormones and accumulation of energy reserves requires time to accomplish. Thus, it is evident that diapause does not occur as an immediate response to a simple worsening of conditions, but rather precedes such worsening. Also, the rapid improvement of environmental conditions cannot initiate the termination of diapause. That is the main difference between diapause and quiescence, which begins or ends practically immediately after a change in the depressive factor, eg temperature. The necessity of clearly distinguishing diapause from sleep and quiescence should not exclude an understanding of the relationship and genetic similarity of these