Ronai Isobel, Allsopp Michael H, Tan Ken, Dong Shihao, Liu Xiwen, Vergoz Vanina, Oldroyd Benjamin P
Behaviour and Genetics of Social Insects Laboratory, School of Biological Sciences A12, University of Sydney, Sydney, New South Wales 2006, Australia
Honeybee Research Section, ARC-Plant Protection Research Institute, Private Bag X5017, Stellenbosch 7599, Western Cape, South Africa.
Proc Biol Sci. 2017 Mar 29;284(1851). doi: 10.1098/rspb.2016.2693.
In the social insects, ovary state (the presence or absence of mature oocytes) and ovary size (the number of ovarioles) are often used as proxies for the reproductive capacity of an individual worker. Ovary size is assumed to be fixed post-eclosion whereas ovary state is demonstrably plastic post-eclosion. Here, we show that in fact ovary size declines as honeybee workers age. This finding is robust across two honeybee species: and The ovariole loss is likely to be due to the regression of particular ovarioles via programmed cell death. We also provide further support for the observation that honeybee workers with activated ovaries (mature oocytes present) most commonly have five ovarioles rather than a greater or smaller number. This result suggests that workers with more than five ovarioles are unable to physiologically support more than five activated ovarioles and that workers with fewer than five ovarioles are below a threshold necessary for ovary activation. As a worker's ovariole number declines with age, studies on worker ovariole number need to take this plasticity into account.
在群居性昆虫中，卵巢状态（成熟卵母细胞的有无）和卵巢大小（卵巢小管的数量）常被用作衡量单个工蜂繁殖能力的指标。卵巢大小被认为在羽化后是固定的，而卵巢状态在羽化后显然具有可塑性。在此，我们表明，事实上，随着蜜蜂工蜂年龄的增长，卵巢大小会减小。这一发现适用于两种蜜蜂，具有很强的普遍性。卵巢小管的减少可能是由于特定卵巢小管通过程序性细胞死亡而退化。我们还进一步支持了以下观察结果：卵巢被激活的蜜蜂工蜂（存在成熟卵母细胞）最常见的卵巢小管数量是五条，而非更多或更少。这一结果表明，卵巢小管数量超过五条的工蜂在生理上无法支持多于五条被激活的卵巢小管，而卵巢小管数量少于五条的工蜂则低于卵巢激活所需的阈值。由于工蜂的卵巢小管数量会随着年龄增长而减少，关于工蜂卵巢小管数量的研究需要考虑到这种可塑性。
