Molecular cloning, characterization, mRNA expression changes and nucleocytoplasmic shuttling during kidney embryonic development of SOX9 in Alligator sinensis

Role of Sox9 in BPD and its effects on the Wnt/β-catenin pathway and AEC-II differentiation

The excessive activation of the Wnt/β-catenin signaling pathway is an important regulatory mechanism that underlies the excessive proliferation and impaired differentiation of type 2 alveolar epithelial cells (AEC-II) in bronchopulmonary dysplasia (BPD). Sox9 has been shown to be an important repressor of the Wnt/β-catenin signaling pathway and plays an important regulatory role in various pathophysiological processes. We found that the increased expression of Sox9 in the early stages of BPD could downregulate the expression of β-catenin and promote the differentiation of AEC-II cells into AEC-I, thereby alleviating the pathological changes in BPD. The expression of Sox9 in BPD is regulated by long noncoding RNA growth arrest-specific 5. These findings may provide new targets for the early intervention of BPD.

gjSOX9 Cloning, Expression, and Comparison with gjSOXs Family Members in Gekko japonicus

SOX9 plays a crucial role in the male reproductive system, brain, and kidneys. In this study, we firstly analyzed the complete cDNA sequence and expression patterns for SOX9 from Gekko japonicus SOX9 (gjSOX9), carried out bioinformatic analyses of physiochemical properties, structure, and phylogenetic evolution, and compared these with other members of the gjSOX family. The results indicate that gjSOX9 cDNA comprises 1895 bp with a 1482 bp ORF encoding 494aa. gjSOX9 was not only expressed in various adult tissues but also exhibited a special spatiotemporal expression pattern in gonad tissues. gjSOX9 was predicted to be a hydrophilic nucleoprotein with a characteristic HMG-Box harboring a newly identified unique sequence, "YKYQPRRR", only present in SOXE members. Among the 20 SOX9 orthologs, gjSOX9 shares the closest genetic relationships with Eublepharis macularius SOX9, Sphacrodactylus townsendi SOX9, and Hemicordylus capensis SOX9. gjSOX9 and gjSOX10 possessed identical physicochemical properties and subcellular locations and were tightly clustered with gjSOX8 in the SOXE group. Sixteen gjSOX family members were divided into six groups: SOXB, C, D, E, F, and H with gjSOX8, 9, and 10 in SOXE among 150 SOX homologs. Collectively, the available data in this study not only facilitate a deep exploration of the functions and molecular regulation mechanisms of the gjSOX9 and gjSOX families in G. japonicus but also contribute to basic research regarding the origin and evolution of SOX9 homologs or even sex-determination mode in reptiles.