Pollard Matthew D, Meyer Wynn K, Puckett Emily E
Department of Biological Sciences, University of Memphis, Memphis, Tennessee 38152, USA;
Center for Biodiversity Research, University of Memphis, Memphis, Tennessee 38152, USA.
Genome Res. 2024 Dec 23;34(12):2176-2189. doi: 10.1101/gr.278930.124.
Mammalia comprises a great diversity of diet types and associated adaptations. An understanding of the genomic mechanisms underlying these adaptations may offer insights for improving human health. Comparative genomic studies of diet that employ taxonomically restricted analyses or simplified diet classifications may suffer reduced power to detect molecular convergence associated with diet evolution. Here, we use a quantitative carnivory score-indicative of the amount of animal protein in the diet-for 80 mammalian species to detect significant correlations between the relative evolutionary rates of genes and changes in diet. We have identified six genes-, , , , , and -that experienced significant changes in evolutionary constraint alongside changes in carnivory score, becoming less constrained in lineages evolving more herbivorous diets. We further consider the biological functions associated with diet evolution and observe that pathways related to amino acid and lipid metabolism, biological oxidation, and small molecule transport experienced reduced purifying selection as lineages became more herbivorous. Liver and kidney functions show similar patterns of constraint with dietary change. Our results indicate that these functions are important for the consumption of animal matter and become less important with the evolution of increasing herbivory. So, genes expressed in these tissues experience a relaxation of evolutionary constraint in more herbivorous lineages.
哺乳动物包含多种多样的饮食类型及相关适应性特征。了解这些适应性背后的基因组机制可能为改善人类健康提供见解。采用分类学上受限分析或简化饮食分类的饮食比较基因组研究，在检测与饮食进化相关的分子趋同方面可能会降低效力。在此，我们使用一种定量食肉分数（指示饮食中动物蛋白的含量）对80种哺乳动物进行分析，以检测基因的相对进化速率与饮食变化之间的显著相关性。我们鉴定出六个基因——、、、、和——它们在食肉分数发生变化的同时，进化约束也经历了显著变化，在向更食草性饮食进化的谱系中约束性降低。我们进一步考虑与饮食进化相关的生物学功能，观察到随着谱系变得更食草，与氨基酸和脂质代谢、生物氧化以及小分子转运相关的通路经历了纯化选择的减少。肝脏和肾脏功能在饮食变化时显示出类似的约束模式。我们的结果表明，这些功能对于动物物质的消耗很重要，并且随着食草性增加的进化而变得不那么重要。因此，在这些组织中表达的基因在更食草的谱系中经历了进化约束的放松。
