DNA methylation is a heritable epigenetic mark present in many eukaryotic organisms. While DNA methylation likely has a conserved role in gene silencing, the levels and patterns vary among organisms. Using shotgun genomic bisulfite sequencing (BS-Seq), the study compared DNA methylation in eight diverse plant and animal genomes. Methylation patterns were similar in flowering plants, with CG methylation predominant in animals. Vertebrates have genome-wide methylation except in CpG islands, while gene body methylation is conserved across organisms. In Ciona and honey bee, genes are the main targets of methylation. The green alga Chlamydomonas has non-CG methylation in exons rather than repeats. The Dnmt1 cofactor Uhrf1 maintains CG methylation in transposons and gene bodies in mouse, Arabidopsis, and zebrafish. DNA methylation is important in gene regulation, including genomic imprinting, X-chromosome inactivation, and transposon silencing. It is conserved in many eukaryotic groups, including plants, animals, and fungi, but not in some model organisms like yeast and nematodes. DNA methylation is categorized into CG, CHG, and CHH contexts. CG methylation is maintained by Dnmt1, while CHH and CHG are maintained by Dnmt3. In vertebrates, CG methylation is global except in CpG islands, while invertebrates, plants, and fungi have mosaic methylation. The study found that gene body methylation is conserved across organisms, with a preference for exons. In Ciona and honey bee, genes are the main targets of methylation. In Chlamydomonas, CG, CHG, and CHH methylation are mediated by Dnmt1/MET1 homologs. In vertebrates, CG methylation is high in gene bodies and low in intergenic regions. The study also found that Uhrf1 is conserved in all eight organisms and plays a role in maintaining CG methylation. Loss of Uhrf1 leads to reduced CG methylation and reactivation of silenced genes. The study highlights the conservation of gene body methylation across plants and animals, suggesting an ancient origin. Exon methylation is more prevalent than intron methylation, possibly due to nucleosome positioning. The study also shows that Uhrf1 is essential for maintaining CG methylation in plants and animals. The findings suggest that DNA methylation is a conserved mechanism for gene regulation and genome stability.DNA methylation is a heritable epigenetic mark present in many eukaryotic organisms. While DNA methylation likely has a conserved role in gene silencing, the levels and patterns vary among organisms. Using shotgun genomic bisulfite sequencing (BS-Seq), the study compared DNA methylation in eight diverse plant and animal genomes. Methylation patterns were similar in flowering plants, with CG methylation predominant in animals. Vertebrates have genome-wide methylation except in CpG islands, while gene body methylation is conserved across organisms. In Ciona and honey bee, genes are the main targets of methylation. The green alga Chlamydomonas has non-CG methylation in exons rather than repeats. The Dnmt1 cofactor Uhrf1 maintains CG methylation in transposons and gene bodies in mouse, Arabidopsis, and zebrafish. DNA methylation is important in gene regulation, including genomic imprinting, X-chromosome inactivation, and transposon silencing. It is conserved in many eukaryotic groups, including plants, animals, and fungi, but not in some model organisms like yeast and nematodes. DNA methylation is categorized into CG, CHG, and CHH contexts. CG methylation is maintained by Dnmt1, while CHH and CHG are maintained by Dnmt3. In vertebrates, CG methylation is global except in CpG islands, while invertebrates, plants, and fungi have mosaic methylation. The study found that gene body methylation is conserved across organisms, with a preference for exons. In Ciona and honey bee, genes are the main targets of methylation. In Chlamydomonas, CG, CHG, and CHH methylation are mediated by Dnmt1/MET1 homologs. In vertebrates, CG methylation is high in gene bodies and low in intergenic regions. The study also found that Uhrf1 is conserved in all eight organisms and plays a role in maintaining CG methylation. Loss of Uhrf1 leads to reduced CG methylation and reactivation of silenced genes. The study highlights the conservation of gene body methylation across plants and animals, suggesting an ancient origin. Exon methylation is more prevalent than intron methylation, possibly due to nucleosome positioning. The study also shows that Uhrf1 is essential for maintaining CG methylation in plants and animals. The findings suggest that DNA methylation is a conserved mechanism for gene regulation and genome stability.