Lennox-Bulow Danica, Courtney Robert, Seymour Jamie
Australian Institute of Tropical Health and Medicine (AITHM), James Cook University, McGregor Road, Cairns, Queensland, Australia.
Australian Institute of Tropical Health and Medicine (AITHM), James Cook University, McGregor Road, Cairns, Queensland, Australia.
Toxicon. 2025 Jul;262:108383. doi: 10.1016/j.toxicon.2025.108383. Epub 2025 May 5.
Geographic variation in the composition of animal toxins is well documented for venomous taxa, and to a lesser degree, for some poisonous taxa that secrete toxins obtained from their diet. However, very little is known about animals that synthesise their poisons de novo, such as stonefish and their secreted ichthyocrinotoxins. Stonefish are widely distributed throughout the Indo-Pacific, however, the effect of location on the composition of their ichthyocrinotoxin is currently unknown. This study aimed to determine whether the composition of ichthyocrinotoxins from Synanceia horrida (Estuarine Stonefish) varied between three geographically isolated Australian populations including Cairns in far north Queensland, Caloundra in southeast Queensland, and Exmouth in Western Australia. The composition of ichthyocrinotoxins from S. horrida were largely conserved across the three locations, with the size of most of the components falling between 14 and 25 kDa. However, unique components were identified in S. horrida ichthyocrinotoxins from Caloundra and Exmouth populations. Caloundra populations contained unique smaller components (8 and 12 kDa) that were hydrophobic. In contrast, Exmouth populations contained unique larger components (60 and 150 kDa) with no difference in hydrophobicity. We speculate that the composition of ichthyocrinotoxins produced by S. horrida are likely influenced by benthic flora and fauna communities, particularly those that are likely to interact with the animal's skin, such as fouling flora and fauna, as well as parasites. These findings further add to the growing body of evidence underscoring the complexity and compositional diversity of ichthyocrinotoxins produced by stonefish.
动物毒素成分的地理差异在有毒类群中已有充分记录，而对于一些从食物中获取毒素并分泌毒素的有毒类群，这种差异程度较小。然而，对于能从头合成毒素的动物，如石鱼及其分泌的鱼毒蛋白，人们知之甚少。石鱼广泛分布于印度 - 太平洋地区，但目前尚不清楚地理位置对其鱼毒蛋白成分的影响。本研究旨在确定来自澳大利亚三个地理隔离种群（包括昆士兰远北的凯恩斯、昆士兰东南部的卡伦德拉以及西澳大利亚的埃克斯茅斯）的褐菖鲉（河口石鱼）的鱼毒蛋白成分是否存在差异。褐菖鲉的鱼毒蛋白成分在这三个地点大体上是保守的，大多数成分的大小在14至25 kDa之间。然而，在卡伦德拉和埃克斯茅斯种群的褐菖鲉鱼毒蛋白中发现了独特成分。卡伦德拉种群含有独特的较小的疏水成分（8和12 kDa）。相比之下，埃克斯茅斯种群含有独特的较大成分（60和150 kDa），其疏水性没有差异。我们推测，褐菖鲉产生的鱼毒蛋白成分可能受底栖动植物群落影响，特别是那些可能与动物皮肤相互作用的群落，如污损动植物以及寄生虫。这些发现进一步增加了越来越多的证据，强调了石鱼产生的鱼毒蛋白的复杂性和成分多样性。
