Identification and differential expression patterns of porcine OCT4 variants

Area of Science:

• Reproductive Biology
• Developmental Biology
• Molecular Genetics

Background:

• Octamer-binding transcription factor 4 (OCT4) is essential for maintaining pluripotency in embryonic stem cells.
• Several OCT4 variants have been identified in mouse and human studies, suggesting diverse functional roles.
• Understanding OCT4 variant expression is crucial for comprehending early embryonic development and tissue-specific functions.

Purpose of the Study:

• To identify and characterize OCT4 variants in porcine embryos and various tissues.
• To analyze the expression patterns and localization of these OCT4 variants.
• To investigate the potential differential roles of OCT4 variants in development and adult tissues.

Main Methods:

• Identification of OCT4 variants (OCT4A, OCT4B, OCT4B1) transcribed from the POU5F1 gene.
• Analysis of mRNA expression levels in preimplantation porcine embryos and adult tissues.
• Protein localization studies in porcine blastocyst stage embryos.
• Correlation analysis with SOX2 and NANOG gene expression.

Main Results:

• The porcine POU5F1 gene transcribes three OCT4 variants: OCT4A, OCT4B, and OCT4B1.
• OCT4A mRNA is predominantly expressed in preimplantation embryos, while OCT4B and OCT4B1 constitute approximately 20%.
• OCT4B mRNA is ubiquitously detected in all examined tissues, whereas OCT4A and OCT4B1 are restricted to the testis.
• OCT4B1 expression inversely correlates with SOX2 and NANOG.
• OCT4A protein localizes to the nucleus, and OCT4B protein to the cytoplasm in blastocyst stage embryos.

Conclusions:

• The porcine OCT4 gene encodes at least three distinct variants with differential expression profiles.
• These variants exhibit tissue-specific and developmental stage-specific expression, suggesting specialized functions.
• OCT4A, OCT4B, and OCT4B1 likely play dissimilar roles in porcine preimplantation embryos and adult tissues.