MLL2 is essential for porcine embryo development in vitro

Area of Science:

• Reproductive Biology
• Developmental Biology
• Epigenetics

Background:

• Germ cell transcription factors are vital for ovarian development and folliculogenesis.
• The role of these factors in early embryonic development remains largely unexplored.

Purpose of the Study:

• To investigate the function of mixed-lineage leukemia protein 2 (MLL2) in porcine preimplantation embryo development.
• To elucidate the molecular mechanisms underlying MLL2's role in early embryonic stages.

Main Methods:

• Quantitative real-time PCR (qRT-PCR) and immunofluorescence assays were used to assess MLL2 expression and localization.
• Mixed-lineage leukemia protein 2 (MLL2) was knocked down using double-stranded RNA (dsRNA).
• Histone 3 trimethylation at lysine 4 (H3K4m3) levels and expression of target genes (Sox2, Magoh) were analyzed.

Main Results:

• MLL2 expression decreased significantly after the four-cell stage, with nuclear localization observed only in blastocysts.
• MLL2 knockdown led to reduced blastocyst formation and impaired expression of Sox2 and Magoh.
• Knockdown of MLL2 significantly reduced H3K4m3 levels in the nucleus.

Conclusions:

• Mixed-lineage leukemia protein 2 (MLL2) plays an essential role in porcine embryo development, particularly at the blastocyst stage.
• MLL2 regulates porcine embryo development through the epigenetic modification of H3K4 methylation.
• MLL2 is critical for maintaining the expression of key developmental genes like Sox2 and Magoh.