Glucose-Induced Developmental Dynamics: Understanding Male Prevalence in Early Mouse Embryo Stages.

Purpose: Glucose plays a critical role in early embryonic development, influencing metabolic dynamics and developmental competence in a sex-specific manner. This study investigates the complex interplay between glucose availability, developmental competence, and sex-specific outcomes in preimplantation mouse embryos. Methods: Mouse embryos were cultured in a modified KSOM medium with varying glucose concentrations (0-20 mM), monitored via time-lapse microscopy, and analyzed for developmental competence, sex determination by PCR, and X-linked metabolic gene expression. Stage-specific glucose addition/removal experiments and PDHA1 immunofluorescence staining were performed to assess temporal glucose dependency and sex-specific metabolic patterns. Results: Glucose is essential during the morula-to-blastocyst transition. Analysis of developmental dynamics showed that glucose concentration affected the variability in developmental rates, particularly at the four-cell and eight-cell stages. Interestingly, sex ratio skewing was observed, with male embryos dominating the early developmental groups regardless of glucose levels. Expression analysis of X-linked metabolic genes revealed stage-specific patterns, with PDHA1 exhibiting the highest activity at the eight-cell stage. Conclusions: Glucose availability accelerated embryonic development and created sex-specific patterns of developmental timing, with male embryos exhibiting faster progression rates, which might be associated with differential X-linked PDHA1 metabolic gene expression during early mouse embryogenesis.