Department of Environmental Science, University of California, Riverside, CA, 2258 Geology, 900 University Ave., Riverside, CA 92521, USA.
Department of Biology, Stanford University, Stanford, CA 94305, USA.
Comp Biochem Physiol C Toxicol Pharmacol. 2019 Feb;216:1-9. doi: 10.1016/j.cbpc.2018.10.004. Epub 2018 Oct 24.
Many reef fishes are capable of feeding on chemically-defended benthic prey, such as soft (alcyonarian) corals; however, little is known about the molecular mechanisms that underpin allelochemical biotransformation and detoxification. Butterflyfishes (Chaetodon: Chaetdontidae) are a useful group for comparatively exploring links between biotransformation enzymes and diet, because they commonly feed on chemically defended prey. Moreover, diets of some species vary among geographic locations. This study compares gene expression, protein and enzymatic activity of key detoxification enzymes (cytochrome P450 (CYP) 2, 3, epoxide hydrolase, glutathione transferase and UDP-glucuronosyltransferase) in livers of four coral-feeding butterflyfish species between Australia and Hawaii, where these fishes differ in diet composition. For C. kleinii, C. auriga, and C. unimaculatus, we found higher CYP2 and CYP3 levels were linked to more allelochemically rich diets in Australia relative to Hawaii. For C. lunulatus from Hawaii CYP2 and CYP3 levels were 1 to 20-fold higher than C. lunulatus from Australia, possibly due to their predominant prey in Hawaii (Porities spp.) being richer in allelochemicals. UGT, GST and epoxide hydrolase varied between species and location and did not correspond to any specific dietary preference or location. Higher levels of CYP2 and CYP3A isozymes in species that feed on allelochemically-rich prey suggest that these biotransformation enzymes may be involved in detoxification of coral dietary allelochemicals in butterflyfishes.
许多珊瑚礁鱼类能够以具有化学防御能力的底栖猎物为食，例如软珊瑚（柳珊瑚）；然而，人们对支持化感物质生物转化和解毒的分子机制知之甚少。蝴蝶鱼（Chaetodon：Chaetodontidae）是一个有用的研究群体，可用于比较探索生物转化酶与饮食之间的联系，因为它们通常以具有化学防御能力的猎物为食。此外，一些物种的饮食在地理位置上有所不同。本研究比较了澳大利亚和夏威夷的四种珊瑚食性蝴蝶鱼肝脏中关键解毒酶（细胞色素 P450（CYP）2、3、环氧化物水解酶、谷胱甘肽转移酶和 UDP-葡萄糖醛酸基转移酶）的基因表达、蛋白质和酶活性，这些鱼类在饮食组成上存在差异。对于 C. kleinii、C. auriga 和 C. unimaculatus，我们发现 CYP2 和 CYP3 水平较高与澳大利亚相对夏威夷具有更多化感物质丰富的饮食有关。对于来自夏威夷的 C. lunulatus，CYP2 和 CYP3 的水平比来自澳大利亚的 C. lunulatus 高 1 到 20 倍，可能是由于它们在夏威夷的主要猎物（Porities spp.）含有更多的化感物质。UGT、GST 和环氧化物水解酶在物种和位置之间存在差异，与任何特定的饮食偏好或位置都不对应。以化感物质丰富的猎物为食的物种中 CYP2 和 CYP3A 同工酶水平较高，表明这些生物转化酶可能参与蝴蝶鱼中珊瑚饮食化感物质的解毒。
