Developmental origins of a novel gut morphology in frogs.
Developmental origins of a novel gut morphology in frogs.
复制标题
青蛙新型肠道形态的发育起源。
DOI：
10.1111/ede.12035
复制
发表时间：
2013
影响因子：
2.9
通讯作者：
Nascone-Yoder,Nanette
中科院分区：
文献类型：
--
作者：
Bloom,Stephanie;Ledon-Rettig,Cris;Infante,Carlos;Everly,Anne;Hanken,James;Nascone-Yoder,Nanette
Phenotypic variation is a prerequisite for evolution by natural selection, yet the processes that give rise to the novel morphologies upon which selection acts are poorly understood. We employed a chemical genetic screen to identify developmental changes capable of generating ecologically relevant morphological variation as observed among extant species. Specifically, we assayed for exogenously applied small molecules capable of transforming the ancestral larval foregut of the herbivorousXenopus laevisto resemble the derived larval foregut of the carnivorousLepidobatrachus laevis. Appropriately, the small molecules that demonstrate this capacity modulate conserved morphogenetic pathways involved in gut development, including downregulation of retinoic acid (RA) signaling. Identical manipulation of RA signaling in a species that is more closely related toLepidobatrachus,Ceratophrys cranwelli, yielded even more similar transformations, corroborating the relevance of RA signaling variation in interspecific morphological change. Finally, we were able to recover the ancestral gut phenotype inLepidobatrachusby performing a reverse chemical manipulation to upregulate RA signaling, providing strong evidence that modifications to this specific pathway promoted the emergence of a lineage‐specific phenotypic novelty. Interestingly, our screen also revealed pathways that have not yet been implicated in early gut morphogenesis, such as thyroid hormone signaling. In general, the chemical genetic screen may be a valuable tool for identifying developmental mechanisms that underlie ecologically and evolutionarily relevant phenotypic variation.
