Santos Douglas Elias, Souza Anderson de Oliveira, Tibério Gustavo Jacomini, Alberici Luciane Carla, Hartfelder Klaus
Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Ribeirão Preto, SP, Brazil.
Universidade de São Paulo, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências BioMoleculares, Ribeirão Preto, SP, Brazil.
Genet Mol Biol. 2020 Nov 13;43(4):e20200173. doi: 10.1590/1678-4685-GMB-2020-0173. eCollection 2020.
The expression of morphological differences between the castes of social bees is triggered by dietary regimes that differentially activate nutrient-sensing pathways and the endocrine system, resulting in differential gene expression during larval development. In the honey bee, Apis mellifera, mitochondrial activity in the larval fat body has been postulated as a link that integrates nutrient-sensing via hypoxia signaling. To understand regulatory mechanisms in this link, we measured reactive oxygen species (ROS) levels, oxidative damage to proteins, the cellular redox environment, and the expression of genes encoding antioxidant factors in the fat body of queen and worker larvae. Despite higher mean H2O2 levels in queens, there were no differences in ROS-mediated protein carboxylation levels between the two castes. This can be explained by their higher expression of antioxidant genes (MnSOD, CuZnSOD, catalase, and Gst1) and the lower ratio between reduced and oxidized glutathione (GSH/GSSG). In worker larvae, the GSG/GSSH ratio is elevated and antioxidant gene expression is delayed. Hence, the higher ROS production resulting from the higher respiratory metabolism in queen larvae is effectively counterbalanced by the up-regulation of antioxidant genes, avoiding oxidative damage. In contrast, the delay in antioxidant gene expression in worker larvae may explain their endogenous hypoxia response.
社会蜜蜂不同蜂种间形态差异的表达是由饮食模式触发的，这些饮食模式会以不同方式激活营养感知途径和内分泌系统，从而在幼虫发育过程中导致基因表达差异。在蜜蜂（西方蜜蜂）中，幼虫脂肪体中的线粒体活性被认为是通过缺氧信号整合营养感知的一个环节。为了了解这一环节的调控机制，我们测量了蜂王和工蜂幼虫脂肪体中的活性氧（ROS）水平、蛋白质的氧化损伤、细胞氧化还原环境以及编码抗氧化因子的基因表达。尽管蜂王体内的平均过氧化氢水平较高，但两个蜂种之间由ROS介导的蛋白质羧化水平并无差异。这可以通过它们较高的抗氧化基因（锰超氧化物歧化酶、铜锌超氧化物歧化酶、过氧化氢酶和谷胱甘肽S-转移酶1）表达以及较低的还原型与氧化型谷胱甘肽比例（GSH/GSSG）来解释。在工蜂幼虫中，GSG/GSSH比例升高且抗氧化基因表达延迟。因此，蜂王幼虫较高的呼吸代谢产生的较高ROS产量通过抗氧化基因的上调得到有效平衡，避免了氧化损伤。相比之下，工蜂幼虫抗氧化基因表达的延迟可能解释了它们的内源性缺氧反应。
