Transcriptome and Proteome of Blastocysts Obtained from Different Activation Protocols

Area of Science:

• Reproductive Biology
• Developmental Biology
• Genomics and Proteomics

Background:

• Normal fertilization induces calcium (Ca2+) oscillations in oocytes, essential for development.
• Assisted oocyte activation (AOA) protocols vary in their Ca2+ dynamics, with unclear effects on early embryo gene expression.

Purpose of the Study:

• To investigate the impact of different AOA protocols on early embryo gene expression.
• To compare transcriptional and proteomic profiles of parthenogenetic embryos with normally fertilized embryos.

Main Methods:

• Utilized three AOA methods: strontium chloride (SrCl2) for Ca2+ oscillations, A-23187 for a single Ca2+ rise, and RO-3306 without Ca2+ rise.
• Analyzed omics data (transcriptomics and proteomics) from parthenogenetic and normally fertilized blastocysts.

Main Results:

• Parthenogenetic blastocysts showed distinct transcriptional and protein expression profiles compared to normal blastocysts.
• Key differences were observed in pathways related to fatty acid metabolism, mitochondria, RNA splicing, and RNA binding.
• Ca2+ rise, particularly oscillations, significantly influenced gene expression, with parthenogenetic embryos exhibiting relatively similar profiles among themselves.

Conclusions:

• Gene expression in parthenogenetic embryos differs significantly from normally fertilized embryos.
• Calcium (Ca2+) signaling, especially oscillations, plays a vital role in regulating proper gene expression during early embryonic development.