Abstract
The turtle carapace is composed of severely deformed fused dorsal vertebrae, ribs, and bone plates. In particular, the lateral growth in the superficial layer of turtle ribs in the dorsal trunk causes an encapsulation of the scapula and pelvis. The recent study suggested that the carapacial ridge (CR) is a new model of epithelial–mesenchymal transition which is essential for the arrangement of the ribs. Therefore, it is necessary to explore the regulatory mechanism of carapacial ridge development to analyze the formation of the turtle shell. However, the current understanding of the regulatory network underlying turtle carapacial ridge development is poor due to the lack of both systematic gene screening at different carapacial ridge development stages and gene function verification studies. In this study, we obtained genome-wide gene transcription and gene translation profiles using RNA sequencing and ribosome nascent-chain complex mRNA sequencing from carapacial ridge tissues of Chinese soft-shell turtle at different development stages. A correlation analysis of the transcriptome and translatome revealed that there were 129, 670, and 135 codifferentially expressed genes, including homodirection and opposite-direction differentially expressed genes, among three comparison groups, respectively. The pathway enrichment analysis of codifferentially expressed genes from the Kyoto Encyclopedia of Genes and Genomes showed dynamic changes in signaling pathways involved in carapacial ridge development. Especially, the results revealed that the Wnt signaling pathway and MAPK signaling pathway may play important roles in turtle carapacial ridge development. In addition, Wnt and Fgf were expressed during the carapacial ridge development. Furthermore, we discovered that Wnt5a regulated carapacial ridge development through the Wnt5a/JNK pathway. Therefore, our studies uncover that the morphogenesis of the turtle carapace might function through the co-operation between conserved WNT and FGF signaling pathways. Consequently, our findings revealed the dynamic signaling pathways acting on the carapacial ridge development of Chinese soft-shell turtle and provided new insights into uncover the molecular mechanism underlying turtle shell morphogenesis.
Highlights
Turtle is one of the ancient reptiles [1,2,3,4,5]
To perform a genome-wide analysis of transcribed and translated genes during the carapacial ridge (CR) development of P. sinensis, which is responsible for the turtle carapace morphogenesis, we collected 14th stage (TK14), 15th stage (TK15), and 16th stage (TK16) CR tissues and performed RNA-seq and Ribosome nascent-chain complex (RNC)-mRNA-seq, as shown in Supplementary Figure S1A–C
After filtering out ribosome RNA (rRNA), the reads were compared with the P. sinensis reference genome using TopHat2 software, and gene reconstruction was undertaken using Cufflinks (File S3 and S4)
Summary
Turtle is one of the ancient reptiles [1,2,3,4,5]. The turtle shell is a fascinating model in the field of evolutionary and developmental biology because of its unique topological structures [2,3]. Kuraku’s group found that Cellular Retinoic Acid-Binding Protein 1 (CRABP-1), Lymphoid enhancer-binding factor 1 (Lef1), and Adenomatosis Polyposis Coli Down-Regulated 1 (APCDD1) were expressed in the CR of stage-14 P. sinensis embryos [5] They noted that β-catenin was transferred into the ectodermal cell nuclei in the CR of stage 14 embryos of the Chinese soft-shell turtle [5]. To clarify the genetic basis of turtle CR development, we selected stages 14, 15, and 16 CR tissue of the Chinese soft-shell turtle as research material and used multiomics correlation of the transcriptome and translatome to systematically analyze the molecular mechanism of the CR development of P. sinensis at both the transcription and translation levels. The determination of the molecular mechanism of CR development in Chinese soft-shell turtle has great scientific significance and provides the genetic basis to further reveal the mechanism of formation of the turtle carapace
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
