School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Hofackerstrasse 30, 4132, Muttenz, Switzerland.
Sci Rep. 2023 Feb 3;13(1):1985. doi: 10.1038/s41598-023-29257-w.
Honeybees are important pollinators of many crops and contribute to biological biodiversity. For years, a decline in bee populations has been observed in certain areas. This decline in honeybees is accompanied by a decrease in pollinator services. One factor contributing to the decline of bee colonies is the exposure to pesticides. Pesticide exposure of bees, among other effects, can negatively affect orientation, memory, immune system function and gene expression. Among the altered expressed genes are transcripts of endocrine regulation and oxidative phosphorylation. Endocrine regulation plays an important role in the development of nurse bees into foragers and oxidative phosphorylation is involved in energy metabolism. Most of these transcriptional changes were investigated using mixed aged honeybees derived from the same colony. Experiments using nurse bees or foragers of the same age but from different colonies are rare. In the present study, effects of the two pesticides chlorpyrifos and pyraclostrobin on the expression of transcripts linked to endocrine regulation and oxidative phosphorylation in foragers of the same age from three different colonies are investigated to fill this gap. These two pesticides were selected because negative effects at sublethal concentrations on bees are known and because they are found in pollen and nectar of crops and wild plants. For this purpose, 20-22 days old foragers of three different colonies were exposed to different sublethal concentrations of the selected fungicides for 24 h, followed by analysis of the expression of buffy, vitellogenin, hbg-3, ilp-1, mrjp1, 2 and 3, cox5a, cox5b and cox17. Some significant changes in gene expression of both endocrine regulation transcripts and oxidative phosphorylation were shown. Furthermore, it became clear that forager bees from different colonies react differently. This is especially important in relation to the risk analysis of pesticides. In addition, it could be shown that the expression of hbg-3 in the brain of bees is a robust marker to distinguish nurse bees from foragers at the molecular biological level. In summary, this study clearly shows that pesticides, which are often detected in pollen and nectar, display negative effects at sublethal concentrations on bees and that it is important to use bees from different colonies for risk assessment of pesticides.
蜜蜂是许多作物的重要传粉媒介，对生物多样性有贡献。多年来，某些地区的蜜蜂数量一直在下降。这种蜜蜂数量的减少伴随着传粉服务的减少。导致蜂群减少的一个因素是接触杀虫剂。除了其他影响外，蜜蜂接触杀虫剂会对定向、记忆、免疫系统功能和基因表达产生负面影响。改变的表达基因中包括内分泌调节和氧化磷酸化的转录本。内分泌调节在将保育蜂发育为觅食蜂的过程中起着重要作用，而氧化磷酸化则参与能量代谢。这些转录变化中的大多数都是使用来自同一蜂群的混合年龄蜜蜂进行研究的。使用来自不同蜂群的相同年龄的保育蜂或觅食蜂进行实验的情况很少见。在本研究中，研究了两种杀虫剂毒死蜱和吡唑菌酯对来自三个不同蜂群的相同年龄觅食蜂的与内分泌调节和氧化磷酸化相关的转录本表达的影响，以填补这一空白。选择这两种杀虫剂是因为已知它们在亚致死浓度下对蜜蜂有负面影响，并且因为它们存在于作物和野生植物的花粉和花蜜中。为此，将 20-22 天大的来自三个不同蜂群的觅食蜂暴露于所选杀真菌剂的不同亚致死浓度下 24 小时，然后分析 buffy、卵黄蛋白原、hbg-3、ilp-1、mrjp1、2 和 3、cox5a、cox5b 和 cox17 的表达。显示了一些与内分泌调节转录本和氧化磷酸化相关的基因表达的显著变化。此外，很明显来自不同蜂群的觅食蜂反应不同。这在与杀虫剂的风险分析有关时尤为重要。此外，还可以证明蜜蜂大脑中 hbg-3 的表达是区分保育蜂和觅食蜂的分子生物学水平上的可靠标志物。总之，本研究清楚地表明，经常在花粉和花蜜中检测到的杀虫剂在亚致死浓度下对蜜蜂有负面影响，使用来自不同蜂群的蜜蜂进行杀虫剂风险评估非常重要。
