Kapheim Karen M, Johnson Makenna M
Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322, USA
Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322, USA.
Proc Biol Sci. 2017 Jan 25;284(1847). doi: 10.1098/rspb.2016.2406.
In social bees, foraging behaviour is correlated with reproductive status and sucrose sensitivity via endocrine pathways. This association led to the hypothesis that division of labour in social insect societies is derived from an ancestral ground plan that functions to synchronize dietary preferences with reproductive needs in solitary insects. However, the relationship between these traits is unknown for solitary bees, which represent the ancestral state of social bees. We used the proboscis extension response assay to measure sucrose response among reproductive females of the solitary alkali bee (Nomia melanderi) as a function of acute juvenile hormone (JH) treatments and reproductive physiology. We also tested long-term effects of JH on reproductive development in newly emerged females. JH did not have short-term effects on reproductive physiology or sucrose response, but did have significant long-term effects on ovary and Dufour's gland development. Dufour's gland size, not ovary development, was a significant predictor of sucrose response. This provides support for the reproductive ground plan hypothesis, because the Dufour's gland has conserved reproductive functions in bees. Differing results from this study and honeybees suggest independent origins of division of labour may have evolved via co-option of different components of a conserved ground plan.
在群居蜜蜂中，觅食行为通过内分泌途径与生殖状态和蔗糖敏感性相关。这种关联引发了一个假说，即群居昆虫社会中的劳动分工源自一种祖先的基本模式，该模式的作用是使独居昆虫的饮食偏好与生殖需求同步。然而，对于代表群居蜜蜂祖先状态的独居蜜蜂而言，这些特征之间的关系尚不清楚。我们使用喙伸展反应试验来测量独居碱蜂（Nomia melanderi）生殖雌蜂的蔗糖反应，将其作为急性保幼激素（JH）处理和生殖生理学的函数。我们还测试了JH对新羽化雌蜂生殖发育的长期影响。JH对生殖生理学或蔗糖反应没有短期影响，但对卵巢和杜氏腺发育有显著的长期影响。杜氏腺大小而非卵巢发育是蔗糖反应的重要预测指标。这为生殖基本模式假说提供了支持，因为杜氏腺在蜜蜂中具有保守的生殖功能。本研究与蜜蜂研究结果的差异表明，劳动分工的独立起源可能是通过对保守基本模式不同组成部分的选择而进化而来的。
