New Phytologist, Journal Year: 2025, Volume and Issue: unknown
Published: April 25, 2025
Summary Genetic degeneration is a striking feature of Y chromosomes, often involving losses many genes carried on the X chromosome. However, time course gene remains unclear. Sex chromosomes plants evolved more recently than animals' highly degenerated ones, making them ideal for studying timing. To investigate Spinacia sex chromosome evolution and degeneration, we compared genome sequences cultivated oleracea , with small Y‐linked region Chr4, its two wild relatives. In spinach closest relative turkestanica duplication (YDR) introduced male‐determining factor into Chr4's low‐recombining pericentromeric region. other words, turnover event occurred in these species' recent common ancestor. The homologous Chr4 distantly related S. tetrandra has c . 133 Mb completely sex‐linked partially region, possibly reflecting ancestral state. Sequence divergence analysis suggests that ‘evolutionary strata’ shortly before lineages split. Consistent hypothesis, YDR species not within older stratum. We discuss unexpected findings genetic genomic rearrangements, repetitive sequence density are all greatest younger
Language: Английский