{"paper_id":"2bd7b6b6-b7ff-4a4a-b6a1-9a52bd1a62e5","body_text":"Abstract\nLampreys are the only ancestrally parasitic vertebrate lineage, yet parasitism has been repeatedly lost alongside a suite of life-history changes, such as loss of migration and juvenile feeding and accelerated maturation. Combining whole-genome resequencing, haplotype-resolved assemblies, hybrid-zone genotyping, multi-tissue transcriptomics, and sperm phenotyping, we map this life-history syndrome in European Lampetra to six chromosomes spanning a mosaic of genomic architectures: a ∼20 Mb low-recombination region on chromosome 1 lacking chromosomal rearrangements within Lampetra but involving inter-specific rearrangements across deep lamprey lineages; a translocated inversion with ecotype-dependent sperm-velocity effects; and ecotype-divergent deletions overlapping genes crucial for nervous system (CNTNAP2) and reproductive development (FSHR). However, this genomic basis is not shared with a convergent sister lineage, pointing to independent routes to a recurring life-history transition in lampreys.\nCompeting Interest Statement\nThe authors have declared no competing interest.","source_license":"CC-BY-4.0","license_restricted":false}