Vasconcelos Ana Caroline Oliveira, Adler Lewis, Bonduriansky Russell
School of Biological, Earth and Environmental Sciences University of New South Wales Sydney New South Wales Australia.
Bioanalytical Mass Spectrometry Facility, Mark Wainwright Analytical Centre University of New South Wales Sydney New South Wales Australia.
Ecol Evol. 2025 Apr 24;15(4):e71243. doi: 10.1002/ece3.71243. eCollection 2025 Apr.
Parents can invest in offspring by transferring environmental factors, such as nutrients or diet-derived defence chemicals, into eggs or embryos. However, in systems where females can reproduce facultatively without a male (facultative parthenogenesis), it is not known how reproductive mode and maternal environment affect offspring provisioning. The facultatively parthenogenetic stick insect sprays a defensive fluid from paired prothoracic glands. Here, we report that some hatchlings of can spray even prior to their first feeding and provide evidence that both eggs and hatchlings contain the same diet-derived chemical (the alkaloid actinidine) that is present in adult defensive spray. We also explored potential causes of variation among hatchlings in the capacity to spray, using a fully crossed experiment to investigate how offspring provisioning is affected by sexual versus parthenogenetic reproduction and high versus low maternal diet. We found that high maternal diet resulted in increased egg size but slower egg development, and maternal diet interacted with genotype to affect hatchling body size. Eggs laid by male-paired females were larger, developed more quickly, and had higher hatching success by comparison with eggs laid by unpaired females, suggesting that mating and fertilisation enhance some aspects of offspring performance. However, hatchlings produced by unpaired females had larger prothoracic glands relative to body size than did hatchlings produced by male-paired females, suggesting that sexual reproduction is associated with reduced provisioning of offspring with defensive chemicals. Our results reveal a novel example of maternal transfer of food-derived defence chemicals to offspring and suggest that offspring provisioning with defence chemicals is affected by female reproductive mode.
父母可以通过将环境因素，如营养物质或饮食衍生的防御化学物质，传递到卵或胚胎中来对后代进行投资。然而，在雌性可以在没有雄性的情况下兼性繁殖（兼性孤雌生殖）的系统中，尚不清楚繁殖模式和母体环境如何影响后代的物质供应。兼性孤雌生殖的竹节虫会从成对的前胸腺中喷出防御液。在此，我们报告称，一些 的孵化幼虫甚至在首次进食之前就能喷出防御液，并提供证据表明卵和孵化幼虫都含有与成年防御喷雾中相同的饮食衍生化学物质（生物碱猕猴桃碱）。我们还利用完全交叉实验探讨了孵化幼虫在喷射能力上存在差异的潜在原因，以研究有性生殖与孤雌生殖以及高母体饮食与低母体饮食如何影响后代的物质供应。我们发现，高母体饮食会导致卵的大小增加，但卵的发育速度减慢，并且母体饮食与基因型相互作用以影响孵化幼虫的体型。与未配对雌性所产的卵相比，与雄性配对的雌性所产的卵更大、发育更快且孵化成功率更高，这表明交配和受精会提高后代性能的某些方面。然而，未配对雌性所产的孵化幼虫相对于体型而言，其前胸腺比与雄性配对的雌性所产的孵化幼虫更大，这表明有性生殖与为后代提供防御化学物质的减少有关。我们的研究结果揭示了母体将食物衍生的防御化学物质传递给后代的一个新例子，并表明为后代提供防御化学物质受到雌性繁殖模式的影响。
