Evolutionary lineage-specific genomic imprinting at the ZNF791 locus

Area of Science:

• Epigenetics and Genomics
• Mammalian Development
• Livestock Genetics

Background:

• Genomic imprinting influences mammalian development and growth through parent-of-origin effects.
• Research on imprinting in domesticated animals is limited, focusing mainly on human and mouse gene orthologs.
• This has hindered the discovery of livestock-specific imprinted genes.

Purpose of the Study:

• To identify genomic imprinting in pigs, a key livestock species.
• To investigate lineage-specific imprinting patterns in mammals.
• To explore mechanisms of maternal DNA methylation imprinting in oocytes.

Main Methods:

• Generation of parthenogenetic and biparental porcine embryos.
• Whole-genome bisulfite sequencing (WGBS) and RNA sequencing (RNA-seq).
• Comparative genomic analysis across eutherian mammals.

Main Results:

• Discovery of a maternally methylated differentially methylated region at the ZNF791 locus in pigs.
• Identification of an imprinted isoform of the ZNF791-like gene and an unannotated antisense transcript.
• ZNF791 exhibits genomic imprinting exclusively in domesticated animals, not in other eutherian mammals studied.

Conclusions:

• The ZNF791 gene demonstrates lineage-specific imprinting, occurring only in domesticated species.
• Transposable element integration, active transcription, and histone modification may establish maternal imprints in porcine and bovine oocytes.
• Findings offer insights into livestock-specific genomic imprinting, with significant agricultural implications.