Physiol Biochem Zool. 2020 Sep/Oct;93(5):396-415. doi: 10.1086/709848.
AbstractNatural dietary shifts offer the opportunity to address the nutritional physiological characters required to thrive on a particular diet. Here, we studied the nutritional physiology of , with populations on Pod Mrčaru, Croatia, that have become omnivorous and morphologically distinct (including the development of valves in the hindgut) from their insectivorous source population on Pod Kopište. We compared gut structure and function between the two island populations of this lizard species and contrasted them with an insectivorous mainland out-group population in Zagreb. On the basis of the adaptive modulation hypothesis, we predicted changes in gut size and structure, digestive enzyme activities, microbial fermentation products (short-chain fatty acids [SCFAs]), and plant material digestibility concomitant with this dietary change. The Pod Mrčaru population had heavier guts than the mainland population, but there were no other differences in gut structure. Most of the enzymatic differences we detected were between the island populations and the out-group population. The Pod Mrčaru lizards had higher amylase and trehalase activities in their hindguts compared with the Pod Kopište population, and the Pod Kopište lizards had greater SCFA concentrations in their hindguts than the omnivorous Pod Mrčaru population. Interestingly, the differences between the Pod Mrčaru and Pod Kopište populations are primarily localized to the hindgut and are likely influenced by microbial communities and a higher food intake by the Pod Mrčaru lizards. Although subtle, the changes in hindgut digestive physiology impact the digestibility of plant material in adult lizards-Pod Mrčaru lizards had higher digestibility of herbivorous and omnivorous diets fed over several weeks in the laboratory than did their source population.
自然饮食变化提供了一个机会，可以研究在特定饮食下茁壮成长所需的营养生理特征。在这里，我们研究了 Pod Mrčaru 岛上克罗地亚的 种群的营养生理学，该种群已经从以昆虫为食的 Pod Kopište 源种群转变为杂食性，并在消化道后端形成瓣膜。我们比较了这一蜥蜴物种的两个岛屿种群的肠道结构和功能，并与萨格勒布的以昆虫为食的大陆外群种群进行了对比。根据适应性调节假说，我们预测与这种饮食变化相关的肠道大小和结构、消化酶活性、微生物发酵产物（短链脂肪酸 [SCFA]）和植物材料消化率会发生变化。Pod Mrčaru 种群的肠道比大陆种群更重，但肠道结构没有其他差异。我们检测到的大多数酶差异存在于岛屿种群和外群种群之间。与 Pod Kopište 种群相比，Pod Mrčaru 种群的后肠中淀粉酶和海藻糖酶活性更高，而 Pod Kopište 种群的后肠中 SCFA 浓度高于杂食性的 Pod Mrčaru 种群。有趣的是，Pod Mrčaru 和 Pod Kopište 种群之间的差异主要局限于后肠，可能受到微生物群落和 Pod Mrčaru 蜥蜴更高的食物摄入量的影响。虽然细微，但后肠消化生理学的变化会影响成年蜥蜴对植物材料的消化率——在实验室中，经过数周的喂养，Pod Mrčaru 蜥蜴对草食性和杂食性饮食的消化率高于其来源种群。
