Kamyab Elham, Kühnhold Holger, Novais Sara C, Alves Luís M F, Indriana Lisa, Kunzmann Andreas, Slater Matthew, Lemos Marco F L
Leibniz Center for Tropical Marine Ecology (ZMT), Bremen, Germany.
MARE-Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria, Peniche, Portugal.
J Comp Physiol B. 2017 Jan;187(1):51-61. doi: 10.1007/s00360-016-1015-z. Epub 2016 Jul 21.
Holothuria scabra is the most valued and cultured tropical sea cucumber, given the great demand of this species for human consumption. However, despite its ecological and economic relevance, little is known regarding its immune responses under thermal stress. Here, the main goal was to study the response of sea cucumbers to temperature stress, assessing sub-organismal alterations and acclimation capacities of juveniles to temperature changes. After changing temperature (1 °C/day) for 6 days, organisms were exposed to temperature conditions of 21 °C (cold), 27 °C (control), and 33 °C (warm) over a 30 day period. At each 15-day interval (T0, T15, and T30), six replicates per condition were killed for biochemical analysis. Immune responses were addressed by studying the activity of phenoloxidase (PO) and prophenoloxidase (ProPO) in the coelomic fluid. Antioxidant defence responses-catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR) enzymatic activities-were measured in the muscle and respiratory tree tissues, whereas oxidative damage was evaluated by measuring levels of superoxide radicals (ROS), DNA-strand breaks and lipid peroxidation (LPO). Juvenile H. scabra increased SOD and PO activities when temperature was elevated, and revealed low levels of ROS and damage in both cold and warm treatments throughout the experiment, confirming the organism's moderate thermal stress. After the short acclimation period, the immune and antioxidant responses prevented damage and maintained homeostasis. This multi-biomarker approach highlights its usefulness to monitor the health of H. scabra and to gain insight concerning the use of this high-valued species in global-scale aquaculture from different temperature regions.
糙海参是最具价值且被养殖的热带海参，因为该物种在人类消费方面有巨大需求。然而，尽管其具有生态和经济意义，但对于其在热应激下的免疫反应却知之甚少。在此，主要目标是研究海参对温度胁迫的反应，评估幼体的亚生物体变化以及对温度变化的适应能力。在以每天1℃的速度改变温度6天后，将生物体在30天的时间内暴露于21℃（低温）、27℃（对照）和33℃（高温）的温度条件下。在每个15天的间隔期（T0、T15和T30），每种条件下杀死6个重复样本用于生化分析。通过研究体腔液中酚氧化酶（PO）和前酚氧化酶（ProPO）的活性来探讨免疫反应。在肌肉和呼吸树组织中测量抗氧化防御反应——过氧化氢酶（CAT）、超氧化物歧化酶（SOD）和谷胱甘肽还原酶（GR）的酶活性，而通过测量超氧自由基（ROS）水平、DNA链断裂和脂质过氧化（LPO）来评估氧化损伤。糙海参幼体在温度升高时SOD和PO活性增加，并且在整个实验过程中，在低温和高温处理下ROS水平和损伤程度均较低，这证实了该生物体具有适度的热应激。经过短暂的适应期后，免疫和抗氧化反应防止了损伤并维持了体内平衡。这种多生物标志物方法突出了其在监测糙海参健康状况以及深入了解在不同温度区域的全球规模水产养殖中使用这种高价值物种方面的有用性。
