Shibao Harunobu, Kutsukake Mayako, Matsuyama Shigeru, Fukatsu Takema, Shimada Masakazu
Commun Integr Biol. 2010 Jan;3(1):1-5. doi: 10.4161/cib.3.1.9694.
For evolution and maintenance of the social systems of insect colonies, caste production should be controlled in response to external cues so that caste ratio in the colony is kept at an optimal range. Recent developments using artificial diet rearing techniques have revealed an underlying mechanism for adaptive control of caste production in a social aphid, Tuberaphis styraci, which has a sterile soldier caste in the 2(nd) instar. Aphid density was the proximate cue that acts on 1(st) instar nymphs and embryos to induce soldier differentiation. The final determination of soldier differentiation occurred postnatally, probably at a late 1(st) instar stage. Direct contact stimuli from live non-soldier aphids mediated the density effect. While coexisting non-soldiers facilitated soldier differentiation in 1(st) instar nymphs, coexisting soldiers acted to suppress such differentiation. These results suggest that caste production in aphid colonies is controlled by positive and negative feedback mechanisms consisting of density-dependent induction and suppression of soldier differentiation. Here, we demonstrate the mechanisms that coordinate aphid society, and provide a striking case of clonal superorganism system where simple responses of colony members to local extrinsic stimuli are integrated into a highly organized regulation of the whole colony.
对于昆虫群落社会系统的进化和维持而言，品级产生应根据外部线索进行控制，以使群落中的品级比例保持在最佳范围内。利用人工饲料饲养技术的最新进展揭示了社会性蚜虫——白松长足大蚜（Tuberaphis styraci）品级产生适应性控制的潜在机制，该蚜虫在二龄时有不育的兵蚜品级。蚜虫密度是作用于一龄若蚜和胚胎以诱导兵蚜分化的直接线索。兵蚜分化的最终决定发生在出生后，可能是在一龄后期。来自活的非兵蚜的直接接触刺激介导了密度效应。虽然共存的非兵蚜促进一龄若蚜的兵蚜分化，但共存的兵蚜则起到抑制这种分化的作用。这些结果表明，蚜虫群落中的品级产生由正反馈和负反馈机制控制，这些机制包括依赖密度的兵蚜分化诱导和抑制。在此，我们展示了协调蚜虫社会的机制，并提供了一个引人注目的克隆超个体系统案例，其中群落成员对局部外部刺激的简单反应被整合到整个群落的高度有组织的调节中。
