Department of Physiology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil.
Department of Physiology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil.
Gen Comp Endocrinol. 2024 Oct 1;357:114598. doi: 10.1016/j.ygcen.2024.114598. Epub 2024 Aug 8.
Environmental cues such as temperature induce macroscopic changes in the molting cycle of crustaceans, however, the physiological mechanisms behind these changes remain unclearWe aimed to investigate the regulatory mechanisms in the intermolt and premolt stages of the Callinectes sapidus molt cycle in response to thermal stimuli. The concentration of ecdysteroids and lipids in the hemolymph, and the expression of heat shock proteins (HSPs) and molt key genes were assessed at 19 °C, 24 °C and 29 °C. The premolt animals exhibited a much larger response to the colder temperature than intermolt animals. Ecdysteroids decreased drastically in premolt animals, whereas the expression of their hepatopancreas receptor (CasEcR) increased, possibly compensating for the low hemolymphatic levels at 19 °C. This decrease might be due to increased HSPs and inhibited ecdysteroidogenesis in the Y-organ. In addition, the molting-inhibiting hormone expression in the X-organ/sinus gland (XO/SG) remained constant between temperatures and stages, suggesting it is constitutive in this species. Lipid concentration in the hemolymph, and the expression of CasEcR and CasHSP90 in the XO/SG were influenced by the molting stage, not temperature. On the other hand, the expression of HSPs in the hepatopancreas is the result of the interaction between the two factors evaluated in the study. Our results demonstrated that temperature is an effective modulator of responses related to the molting cycle at the endocrine level and that temperature below the control condition caused a greater effect on the evaluated responses compared to the thermostable condition, especially when the animal was in the premolt stage.
环境线索，如温度，诱导甲壳类动物蜕皮周期的宏观变化，然而，这些变化背后的生理机制尚不清楚。我们旨在研究温度刺激下中国明对虾蜕皮周期的间蜕和预蜕阶段的调节机制。在 19°C、24°C 和 29°C 时，评估了血淋巴中蜕皮甾酮和脂质的浓度，以及热休克蛋白（HSPs）和蜕皮关键基因的表达。预蜕期动物对较冷温度的反应比间蜕期动物大得多。蜕皮甾酮在预蜕期动物中急剧下降，而其肝胰腺受体（CasEcR）的表达增加，可能补偿了 19°C 时血淋巴水平较低的情况。这种下降可能是由于 Y 器官中 HSPs 的增加和蜕皮甾酮生物合成的抑制。此外，X 器官/窦腺（XO/SG）中蜕皮抑制激素的表达在温度和阶段之间保持不变，表明在该物种中它是组成型的。血淋巴中的脂质浓度以及 XO/SG 中的 CasEcR 和 CasHSP90 的表达受蜕皮阶段的影响，而不受温度的影响。另一方面，HSPs 在肝胰腺中的表达是研究中评估的两个因素相互作用的结果。我们的研究结果表明，温度是内分泌水平上与蜕皮周期相关的反应的有效调节剂，并且低于对照条件的温度对评估的反应产生的影响大于稳定温度，尤其是当动物处于预蜕期时。
