SSPOP and scoliosis: In a zebrafish forward genetic screen for adult viable scoliosis mutants, Troutwine et al. (2020) studied two recessive hypomorphic alleles harboring missense mutations in sspo. In contrast to null sspo alleles, the RF of hypomorphic mutants appeared devoid of defects during the initial assembly phase, but it progressively became abnormal until its disappearance at 10 days post-fertilization (dpf), at the same time that appears the curved axis phenotype (Troutwine et al., 2020).