The Drosophila SUN protein Spag4 cooperates with the coiled-coil protein Yuri Gagarin to maintain association of the basal body and spermatid nucleus.

Maintaining the proximity of centrosomes to nuclei is important in several cellular contexts, and LINC complexes formed by SUN and KASH proteins are crucial in this process. Here, we characterize the presumed Drosophila ortholog of the mammalian SUN protein, sperm-associated antigen 4 (Spag4, previously named Giacomo), and demonstrate that Spag4 is required for centriole and nuclear attachment during spermatogenesis. Production of spag4 mRNA is limited to the testis, and Spag4 protein shows a dynamic pattern of association with the germline nuclei, including a concentration of protein at the site of attachment of the single spermatid centriole.

Characterization of the overlapping expression patterns of the zebrafish LIS1 orthologs.

Mutations in the LIS1 (Lissencephaly-1) gene underlie classical lissencephaly. This neurodevelopmental disorder is characterized by a loss of cortical gyri and improper laminar formation of the brain due to impaired neuronal migration. Patients with type 1 lissecephaly present with mental retardation and an increased risk of developing other disorders resulting from abnormal neurodevelopment, such as epilepsy.

Disc1 regulates foxd3 and sox10 expression, affecting neural crest migration and differentiation.

This work reports the characterization and functional analysis of disrupted in schizophrenia 1 (disc1), a well-documented schizophrenia-susceptibility gene, in zebrafish cranial neural crest (CNC). Our data demonstrated that disc1 was expressed in zebrafish CNC cells. Loss of Disc1 resulted in persistent CNC cell medial migration, dorsal to the developing neural epithelium, and hindered migration away from the region dorsal to the neural rod.