Functional Analysis of the Inner Nuclear Membrane Protein MAN1 in Zebrafish Adults and Embryos

Abstract

ZMAN1 protein was identified in the brain, the gills, the liver, the kidney and the muscle tissue of the adult zebrafish. It is ubiquitously present in the brain and gill tissues. Using immunofluorescence on adult and embryonic cell lines, ZMAN1 was observed at the nuclear periphery. Moreover, cytoplasmic localization of ZMAN1 during mitotic phases indicates that ZMAN1 is not associated to mitotic chromosomes. ZMAN1 appeared at the surface of the new nuclear envelope at the beginning of nuclear reassembly. ZMAN1 distribution in blastula embryos was in the cytoplasm at different mitotic stages except for interphase, telophase and cytokinesis where it was targeted to the nuclear envelope. The maternally synthesized ZMAN1 was localized to the tail/posterior trunk of mid-pharyngula embryos and showed a very low expression and distribution patterns in the muscle tissue suggesting down-regulation of ZMAN1 at the adult stage. I also detected phenotypical abnormalities in ZMAN1 morphants, displayed a curved tail, dysfunctional tail vasculature and an enlarged pericadium, suggesting a possible function of ZMAN1 in blood vessels and heart morphogenesis. Altogether, my data suggest that ZMAN plays a role in early developmental processes and during the adult life of zebrafish.