T2T genome of the basal nematode Xiphinema index reveals major adaptive events associated with plant parasitism and epigenetic regulation

The genome of Xiphinema index reveals a vertebrate-like epigenetic machinery and a unique plant-derived horizontal gene transfer linked to parasitism.

• Why it matters: Understanding the molecular basis of parasitism and epigenetic regulation in early-branching nematodes is limited by scarce genome resources, hindering insights into their evolutionary adaptations.
• What they did: The study presents a telomere-to-telomere genome assembly of Xiphinema index, identifying a plant-derived HGT gene associated with parasitism and uncovering an extensive epigenetic toolkit including DNA methyltransferases, ATRX, and CTCF, with genome-wide CpG methylation detected.
• The result: These findings suggest that early-branching nematodes possess a vertebrate-like epigenetic system and have acquired plant genes for parasitism, prompting a reevaluation of nematode and animal epigenetic paradigms.