Work

A comprehensive embryonic staging series of the turtle Trachemys scripta

Year: 2025

Type: article

Abstract: BACKGROUND: Turtles hold a unique place in vertebrate evolutionary history, making them critical assets in embryology research. Yet, they remain understudied as potential model organisms in the field. Here, to support experimental manipulations with turtle embryos, we have created a complete normal table of development for comprehensive embryonic staging of Trachemys scripta, one of the most common invasive turtle species worldwide. RESULTS: The development of T. scripta embryos from 0 days post-oviposition (DPO) to hatching (~60 DPO) was described from approximately 300 viable eggs collected at California State University, Northridge during the 2021-2024 nesting seasons. Thirty-one stages between oviposition and hatching were identified, and anatomical structures were cataloged using the Standard Event System (SES) chart. Morphological characteristics were imaged using bright-field microscopy and, for 4',6-diamidino-2-phenylindole-stained embryos, confocal microscopy. CONCLUSION: To facilitate further research with Chelonian embryos, this staging series blends previously accepted staging practices with new details of T. scripta gastrulation, SES criteria, and a photographic annotated glossary.

Source: Developmental Dynamics

DOI: 10.1002/dvdy.70034