Embryo cell allocation patterns are not altered by biopsy but can be linked with further development

Area of Science:

• Developmental Biology
• Reproductive Science

Background:

• Early embryonic development involves cell allocation patterns potentially linked to the embryonic-abembryonic axis.
• The impact of embryo biopsy on these patterns and subsequent development requires investigation.

Purpose of the Study:

• To investigate the effects of embryo biopsy on cell allocation patterns at the blastocyst stage in mice.
• To assess the influence of these patterns on post-implantation development and organogenesis.

Main Methods:

• Mouse embryos were traced with lipophilic dyes to observe cell allocation patterns (orthogonal, deviant, random) at the blastocyst stage.
• Embryos were biopsied at the 8-cell stage, and total cell counts were analyzed.
• Biopsied and non-biopsied embryos were transferred to foster mothers, with pup organ weights assessed post-birth.

Main Results:

• Random cell allocation patterns were most frequent (≈60%), unaffected by biopsy.
• Deviant embryos exhibited reduced total cell counts post-biopsy.
• No significant differences in implantation, litter size, or most organ weights were observed between patterns.
• Deviant pups had heavier hearts, and orthogonal pups had lighter kidneys.

Conclusions:

• Single blastomere removal does not disrupt established cell allocation patterns during mouse pre-implantation development.
• Embryos with different cell allocation patterns may possess distinct coping mechanisms for in vitro procedures.
• Potential alterations in further development exist for embryos exhibiting specific cell allocation patterns following manipulation.