6mA Modification Genomic Distribution and Evolutionary Patterns in Plants

One of the epigenetic alterations is the amino acid N⁶-methyladenine (6mA). Although 6mA and 5-methylcytosine (5mC) were both found at the same time, eukaryotes have only lately begun to pay attention to it, primarily because of the limits of detection technologies.

In eukaryotes, the methylation of genomic DNA is essential for maintaining genome integrity and regulating gene expression. The evolution of 6mA methylation on genes throughout species divergence and the divergence of several duplicate genes is not well understood.

Researchers from the Wuhan Botanical Garden of the Chinese Academy of Sciences (CAS) examined the variations in 6mA methylation within four wild species of Nelumbo nucifera as well as the patterns of 6mA methylation between N. nucifera, Arabidopsis thaliana, and Oryza sativa orthologs to comprehend the evolution of 6mA methylation.

Oxford Nanopore Technologies long-read sequencing was used to sequence and assemble four high-quality lotus reference genomes into a pseudochromosome.

No similarities between the 6mA sites and the extensively researched 5mC methylation sites in lotus have been found by distribution analysis. In high and widespread expression genes with long lengths in distantly related plants, 6mA sites are consistently enriched at the start sites, positively linked with gene expression, and preferentially preserved.

When compared to locally duplicated genes and during the long-term evolution of plant species, whole-genome duplications are more likely to maintain 6mA alterations.