Evolution & Ecology Research Centre, School of Biological, Earth & Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia.
Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia.
Mol Ecol. 2022 Oct;31(19):4949-4961. doi: 10.1111/mec.16633. Epub 2022 Aug 4.
Gene expression levels are key molecular phenotypes at the interplay between genotype and environment. Mounting evidence suggests that short-term changes in environmental conditions, such as those encountered in captivity, can substantially affect gene expression levels. Yet, the exact magnitude of this effect, how general it is, and whether it results in parallel changes across populations are not well understood. Here, we take advantage of the well-studied cane toad, Rhinella marina, to examine the effect of short-term captivity on brain gene expression levels, and determine whether effects of captivity differ between long-colonized and vanguard populations of the cane toad's Australian invasion range. We compared the transcriptomes of wild-caught toads immediately assayed with those from toads captured from the same populations but maintained in captivity for seven months. We found large differences in gene expression levels between captive and wild-caught toads from the same population, with an over-representation of processes related to behaviour and the response to stress. Captivity had a much larger effect on both gene expression levels and gene expression variability in toads from vanguard populations compared to toads from long-colonized areas, potentially indicating an increased plasticity in toads at the leading edge of the invasion. Overall, our findings indicate that short-term captivity can induce large and population-specific transcriptomic changes, which has significant implications for studies comparing phenotypic traits of wild-caught organisms from different populations that have been held in captivity.
基因表达水平是基因型与环境相互作用的关键分子表型。越来越多的证据表明，环境条件的短期变化，如在圈养环境中遇到的变化，会显著影响基因表达水平。然而，这种影响的确切程度、普遍性以及它是否会导致不同种群的平行变化，还不是很清楚。在这里，我们利用研究充分的甘蔗蟾蜍 Rhinella marina，研究短期圈养对大脑基因表达水平的影响，并确定圈养对甘蔗蟾蜍澳大利亚入侵范围的长期殖民和先锋种群的影响是否不同。我们比较了立即进行分析的野生捕获蟾蜍和从同一种群中捕获但在圈养中饲养了七个月的蟾蜍的转录组。我们发现，来自同一种群的圈养和野生捕获蟾蜍之间的基因表达水平存在很大差异，与行为和应激反应相关的过程过度表达。与来自长期殖民地区的蟾蜍相比，圈养对先锋种群的蟾蜍的基因表达水平和基因表达变异性都有更大的影响，这可能表明在入侵前沿的蟾蜍中，可塑性增加。总的来说，我们的研究结果表明，短期圈养可以诱导大规模的、具有种群特异性的转录组变化，这对比较来自不同种群的野生捕获生物的表型特征的研究具有重要意义，因为这些生物在圈养中被捕获。
