Cdk1 heterozygosity triggers premeiotic endoreplication and unreduced sperm formation via the Cdk2/Ccne1-Fzr1a pathway in loach, a teleost.
This study elucidates the molecular pathway for unreduced gamete production in fish and establishes Cdk1 as a key guardian of diploidy before meiosis and offers a targeted strategy for chromosome set manipulation in aquaculture.