Evolutionary Biology, Bielefeld University, Konsequenz 45, Bielefeld, 33615, Germany.
Department of Evolutionary Anthropology, University of Vienna, Djerassiplatz 1, Vienna, 1030, Austria.
BMC Genomics. 2024 Jul 15;25(1):694. doi: 10.1186/s12864-024-10573-y.
Animals plastically adjust their physiological and behavioural phenotypes to conform to their social environment-social niche conformance. The degree of sexual competition is a critical part of the social environment to which animals adjust their phenotypes, but the underlying genetic mechanisms are poorly understood. We conducted a study to investigate how differences in sperm competition risk affect the gene expression profiles of the testes and two brain areas (posterior pallium and optic tectum) in breeding male zebra finches (Taeniopygia castanotis). In this pre-registered study, we investigated a large sample of 59 individual transcriptomes. We compared two experimental groups: males held in single breeding pairs (low sexual competition) versus those held in two pairs (elevated sexual competition) per breeding cage. Using weighted gene co-expression network analysis (WGCNA), we observed significant effects of the social treatment in all three tissues. However, only the treatment effects found in the pallium were confirmed by an additional randomisation test for statistical robustness. Likewise, the differential gene expression analysis revealed treatment effects only in the posterior pallium (ten genes) and optic tectum (six genes). No treatment effects were found in the testis at the single gene level. Thus, our experiments do not provide strong evidence for transcriptomic adjustment specific to manipulated sperm competition risk. However, we did observe transcriptomic adjustments to the manipulated social environment in the posterior pallium. These effects were polygenic rather than based on few individual genes with strong effects. Our findings are discussed in relation to an accompanying paper using the same animals, which reports behavioural results consistent with the results presented here.
动物会灵活地调整其生理和行为表型，以适应其社会环境——社会生态位顺应。性竞争的程度是动物调整其表型的社会环境的一个关键部分，但潜在的遗传机制知之甚少。我们进行了一项研究，以调查精子竞争风险的差异如何影响繁殖雄性斑马雀（Taeniopygia castanotis）的睾丸和两个脑区（后脑皮层和视顶盖）的基因表达谱。在这项预先注册的研究中，我们研究了 59 个个体转录组的大样本。我们比较了两个实验组：单对繁殖的雄性（低性竞争）与每繁殖笼中两对繁殖的雄性（高性竞争）。使用加权基因共表达网络分析（WGCNA），我们观察到所有三种组织中社会处理的显著影响。然而，只有在额外的随机化测试中，我们才确认了在脑皮层中发现的处理效应，以确保统计稳健性。同样，差异基因表达分析仅在脑皮层后部（10 个基因）和视顶盖（6 个基因）中发现了处理效应。在单个基因水平上，睾丸没有发现处理效应。因此，我们的实验并没有为特定于操纵的精子竞争风险的转录组调整提供强有力的证据。然而，我们确实观察到了在脑皮层后部对操纵的社会环境的转录组调整。这些影响是多基因的，而不是基于少数具有强烈影响的个体基因。我们的发现与使用相同动物的一篇配套论文有关，该论文报告了与这里提出的结果一致的行为结果。
