Deciphering reproductive polyphenism in aphids
Deciphering reproductive polyphenism in aphids
复制标题
破译蚜虫的生殖多态性
DOI：
10.1080/07924259.2005.9652172
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发表时间：
2005
影响因子：
0.8
通讯作者：
J. Simon
中科院分区：
文献类型：
--
作者：
D. Tagu;B. Sabater;J. Simon
多型性，允许一个给定的基因型产生几个离散的表型，是表型可塑性的极端情况，主要存在于节肢动物中。社会性昆虫是随着殖民地种姓发展而出现的多型现象的典型例子。然而，蚜虫显示出最大范围的多型性，特别是通过产生有翼或无翼，以及无性或有性形式，这取决于环境条件。在春季和夏季，蚜虫通过胎生单性生殖繁殖，而在秋季，它们进入有性生殖。这种生殖模式的转换是由光周期和温度的变化触发的。在这里，自20世纪60年代以来积累的数据识别的光周期时钟，计数器和假定的神经光感受器参与这一生殖转变进行审查。在感知之后，光周期信号通过激素的分泌（很可能涉及保幼激素）进行转导，激素反过来可以作用于靶细胞，即卵母细胞。在短日照条件下，卵母细胞进入减数分裂并产生单倍体卵，其在受精后发育成2n胚胎。相比之下，在长日照条件下，一次成熟分裂产生2n个卵母细胞，这些卵母细胞立即进入孤雌胚胎发生。提出了蚜虫有性生殖与无性生殖决定的生理学模型，并从新近开展的分子生物学研究的角度进行了展望。
Summary Polyphenism, which allows one given genotype to produce several discrete phenotypes, is an extreme case of phenotypic plasticity and is mainly found in arthropods. Social insects are the canonical example of polyphenism with the development of castes in the colonies. However, aphids display one of the largest range of polyphenisms, notably by producing winged or wingless, as well as asexual or sexual forms, depending on environmental conditions. During spring and summer, aphids reproduce by viviparous parthenogenesis, whereas in autumn they enter sexual reproduction. This switch in reproductive mode is triggered by changes in photoperiod and temperature. Here, the data accumulated since the 1960s on the identification of photoperiodic clocks, counter and putative neural photoreceptors that participate in this reproductive shift are reviewed. After perception, the photoperiodic signal is transduced through the secretion of hormones (juvenile hormones may well be involved) which, in turn, may act on the target cells, namely the oocytes. In short-day conditions, oocytes enter meiosis and produce haploid eggs which develop a 2n embryo after fertilisation. By contrast, in long-day conditions, a single maturation division produces 2n oocytes which immediately enter parthenogenetic embryogenesis. A physiological model of the determination of sexual vs. asexual reproduction in aphids is proposed and viewed from the perspective of newly initiated molecular studies.