Morphological and transcriptomic analyses of embryonic development of red-eared slider Trachemys scripta elegans

Area of Science:

• Developmental Biology
• Herpetology
• Comparative Embryology

Background:

• Turtles are ancient reptiles with unique anatomy, but their embryonic development is not fully understood.
• The red-eared slider (Trachemys scripta elegans) is a globally distributed turtle species.
• Understanding turtle embryogenesis provides insights into vertebrate development.

Purpose of the Study:

• To elucidate the embryonic development process of the red-eared slider turtle.
• To identify key morphological stages and molecular pathways involved in turtle embryogenesis.
• To investigate the role of specific signaling pathways in turtle embryonic development.

Main Methods:

• Observation of embryonic development over a 61-day incubation period at 28°C.
• Classification of development into 27 stages and 3 phases based on morphology and size.
• Transcriptome analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis.
• Real-time fluorescence quantitative PCR to validate gene expression.

Main Results:

• Embryonic development was divided into 27 stages, characterized by growth, organogenesis, and formation of carapace and plastron.
• Transcriptome analysis revealed enrichment in developmental, metabolic, and cellular process pathways.
• The axon guidance pathway was identified as crucial, with upregulation of wnt5a and bmp7 genes observed at specific developmental stages.

Conclusions:

• This study provides a comprehensive staging of red-eared slider embryonic development.
• It highlights the significance of the axon guidance pathway and specific genes (wnt5a, bmp7) in turtle development.
• The findings contribute to the theoretical understanding of embryology and offer molecular insights into turtle development.