Developmental table of the early mouse post-implantation embryo

Area of Science:

• Developmental Biology
• Embryology
• Toxicology

Background:

• Existing mouse embryonic developmental tables lack correlation between embryo growth and differentiation.
• Quantitative data on early somite mouse embryos is needed for precise developmental staging.

Purpose of the Study:

• To establish quantitative data on normal mouse embryonic development from 0 to 30 somite pairs.
• To create a detailed reference table correlating embryo growth and differentiation.
• To compare in vivo and in vitro mouse embryo development.

Main Methods:

• Quantitative measurements of growth (crown-rump length, head length, 280 nm absorbancy) and differentiation (morphological score) were recorded for 168-310 explanted mouse embryos.
• Embryos were staged by somite pair number (0-30).
• Development of 67 post-implantation embryos cultured in vitro was compared to the in vivo reference table.

Main Results:

• A detailed table correlating growth and differentiation parameters with somite stage was generated for mouse embryos.
• Major developmental events were described for each stage.
• In vitro cultured embryos exhibited growth and differentiation patterns similar to in vivo developed embryos.

Conclusions:

• The new reference table provides a practical overview of mouse embryonic development, aiding embryologists and toxicologists.
• In vitro culture methods appear to accurately recapitulate in vivo embryonic development.
• This detailed staging system enhances the study of embryonic development and potential toxicological impacts.