Species adaptation to laboratory conditions is a special case of domestication that has modified model organisms phenotypically and genetically. The characterisation of these changes is crucial to understand how this variation can affect the outcome of biological experiments. Yet despite the wide use of laboratory animals in biological research, knowledge of the genetic diversity within and between different strains and populations of some animal models is still scarce. This is particularly the case of the Mexican axolotl, which has been bred in captivity since 1864. Using gene expression data from nine different projects, nucleotide sequence variants were characterised, and distinctive genetic background of the experimental specimens was uncovered. This study provides a catalogue of thousands of nucleotide variants along predicted protein-coding genes, while identifying genome-wide differences between pigment phenotypes in laboratory populations. Awareness of the genetic variation could guide a better experimental design while helping to develop molecular tools for monitoring genetic diversity and studying gene functions in laboratory axolotls. Overall, this study highlights the cross-taxa utility that transcriptomic data might have to assess the genetic variation of the experimental specimens, which might help to shorten the journey towards reproducible research.

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动物模型驯化过程中的变异：以墨西哥蝾螈为例

物种对实验室条件的适应是驯化的一个特例，它在表型和遗传上改变了模式生物。这些变化的表征对于理解这种变化如何影响生物实验的结果至关重要。然而，尽管实验动物在生物学研究中得到广泛使用，但对某些动物模型的不同品系和种群内部和之间的遗传多样性的了解仍然很少。墨西哥蝾螈的情况尤其如此，该蝾螈自 1864 年以来一直在圈养中繁殖。利用来自九个不同项目的基因表达数据，对核苷酸序列变异进行了表征，并揭示了实验样本的独特遗传背景。这项研究提供了沿着预测的蛋白质编码基因的数千个核苷酸变异的目录，同时识别了实验室人群中色素表型之间的全基因组差异。对遗传变异的认识可以指导更好的实验设计，同时有助于开发用于监测实验室蝾螈遗传多样性和研究基因功能的分子工具。总体而言，这项研究强调了转录组数据可能具有评估实验样本遗传变异的跨分类群效用，这可能有助于缩短可重复研究的旅程。