Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
Proc Biol Sci. 2022 Oct 26;289(1985):20221764. doi: 10.1098/rspb.2022.1764.
Increasing evidence suggests that many novel traits might have originated via plasticity-led evolution (PLE). Yet, little is known of the developmental processes that underpin PLE, especially in its early stages. One such process is 'phenotypic accommodation', which occurs when, in response to a change in the environment, an organism experiences adjustments across variable parts of its phenotype that improve its fitness. Here, we asked if environmentally induced changes in gene expression are enhanced or reversed during phenotypic accommodation of a novel, complex phenotype in spadefoot toad tadpoles (). More genes than expected were affected by both the environment and phenotypic accommodation in the liver and brain. However, although phenotypic accommodation primarily reversed environmentally induced changes in gene expression in liver tissue, it enhanced these changes in brain tissue. Thus, depending on the tissue, phenotypic accommodation may either minimize functional disruption via reversal of gene expression patterns or promote novelty via enhancement of existing expression patterns. Our study thereby provides insights into the developmental origins of a novel phenotype and the incipient stages of PLE.
越来越多的证据表明，许多新的特征可能是通过可塑性主导的进化（PLE）产生的。然而，人们对支持 PLE 的发育过程知之甚少，尤其是在其早期阶段。这样的过程之一是“表型适应”，当生物体在环境变化时，它会在其表型的可变部分经历调整，从而提高其适应性。在这里，我们想知道在锹形虫蟾蜍蝌蚪（）的新型复杂表型的表型适应过程中，环境诱导的基因表达变化是否会增强或逆转。在肝脏和大脑中，受环境和表型适应影响的基因数量超过预期。然而，尽管表型适应主要在肝脏组织中逆转了环境诱导的基因表达变化，但它增强了大脑组织中的这些变化。因此，根据组织的不同，表型适应可能通过逆转基因表达模式来最小化功能障碍，也可能通过增强现有表达模式来促进新颖性。我们的研究因此提供了对新型表型的发育起源和 PLE 初期阶段的深入了解。
