Chang, L.; Zhang, M.; Chen, Q.; Liu, J.; Zhu, W.; Jiang, J. From Water to Land: The Structural Construction and Molecular Switches in Lungs during Metamorphosis of Microhyla fissipes. Biology2022, 11, 528.
Chang, L.; Zhang, M.; Chen, Q.; Liu, J.; Zhu, W.; Jiang, J. From Water to Land: The Structural Construction and Molecular Switches in Lungs during Metamorphosis of Microhyla fissipes. Biology 2022, 11, 528.
Chang, L.; Zhang, M.; Chen, Q.; Liu, J.; Zhu, W.; Jiang, J. From Water to Land: The Structural Construction and Molecular Switches in Lungs during Metamorphosis of Microhyla fissipes. Biology2022, 11, 528.
Chang, L.; Zhang, M.; Chen, Q.; Liu, J.; Zhu, W.; Jiang, J. From Water to Land: The Structural Construction and Molecular Switches in Lungs during Metamorphosis of Microhyla fissipes. Biology 2022, 11, 528.
Abstract
Metamorphosis is a critical process for most anurans to transition from water to land. The appearance of air-breathing lungs occurs during the change in oxygen medium from water to air. Revealing the structural construction and molecular switches of lung organogenesis is essential to understand the realization of air-breathing function. In this study, histology and transcriptomics were combinedly conducted to explore these issues in Microhyla fissipes lungs during metamorphosis. During the pro-metamorphic phase, histological structure improving of the alveolar wall was accompanied by robust substrate metabolism and protein turnover. The lungs, at the metamorphic climax phase, are characterized by an increased number of cilia in the alveolar epithelial cells and collagenous fibers in the connective tissues, corresponding to the transcriptional upregulation of cilia and extracellular matrix-related genes. The post-metamorphic lungs strengthen the contracting function, as suggested by the thickened muscle layer and the upregulated expression of genes involved in muscle contraction. The blood–gas barrier is fully developed in adult lungs whose transcriptional features are tissue growth and differentiation regulation and immunity. Importantly, significant transcriptional switches of pulmonary surfactant protein and hemoglobin facilitate air-breathing. Our results illuminated four key steps of lung development for amphibians to transition from water to land.
Biology and Life Sciences, Animal Science, Veterinary Science and Zoology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
