Zhang Kai, Nakamura Satoshi, Furukawa Seiichi
Doctoral Program in Biosphere Resource Science and Technology, University of Tsukuba, Tsukuba 305-8572, Japan.
Japan International Research Centre for Agricultural Sciences (JIRCAS), Tsukuba 305-8686, Japan.
Insects. 2023 Jul 3;14(7):602. doi: 10.3390/insects14070602.
(Diptera: Tachinidae) is an endoparasitoid that develops inside the lepidopteran host. When the larva of penetrates into the host, (Lepidoptera: Noctuidae), the larva creates a cap-like structure, called the funnel, by using host hemocytes, forming a respiratory attachment to permit efficient respiration. A newly described cloudy and cottony structure, called the "cloak", is formed outside the funnel within 24 h of parasitism. The cloak contains the host fat body and hemocytes. In this study, we aimed to clarify the function of the cloak, which has to date remained unknown. We hypothesized that the funnel generates reactive oxygen species (ROS) through melanization, and that the cloak detoxifies them. We confirmed that the black pigments of the funnel were caused by melanization, which inevitably generates ROS that are potentially harmful to the larva inside the funnel. The cloak showed high activities of antioxidant enzymes, including superoxide dismutase, glutathione peroxidase, and catalase. These results suggest that the cloak scavenged the ROS from the melanized funnel through the diversion of antioxidant enzymes in the fat body, thereby protecting the larva from oxidative damage.
（双翅目：寄蝇科）是一种内寄生蜂，在鳞翅目宿主内发育。当 的幼虫侵入宿主 （鳞翅目：夜蛾科）时，幼虫利用宿主血细胞形成一种帽状结构，称为漏斗，形成呼吸附着以实现高效呼吸。一种新描述的浑浊且呈棉絮状的结构，称为“披风”，在寄生后24小时内在漏斗外部形成。披风包含宿主脂肪体和血细胞。在本研究中，我们旨在阐明迄今为止仍未知的披风的功能。我们假设漏斗通过黑化产生活性氧（ROS），而披风对其进行解毒。我们证实漏斗的黑色色素是由黑化引起的，黑化不可避免地会产生活性氧，这些活性氧可能对漏斗内的 幼虫有害。披风表现出高活性的抗氧化酶，包括超氧化物歧化酶、谷胱甘肽过氧化物酶和过氧化氢酶。这些结果表明，披风通过脂肪体中抗氧化酶的转移清除了黑化漏斗产生的活性氧，从而保护 幼虫免受氧化损伤。
