Cell type-specific expression of nuclear lamina proteins during development of Xenopus laevis.
The cell type-specific expression of the major nuclear lamina polypeptides ("lamins") during development of Xenopus was studied using two monoclonal antibodies (L(0)46F7: specific for LIII, the single lamin of oocytes; PKB8: specific for LI and LII of some somatic cells). In the oocyte, LIII localizes in the nuclear polymer, but upon nuclear envelope breakdown it is solubilized to a form sedimenting at 9 S. In early embryos, LIII contributes to nuclear lamina formation until its depletion. Correspondingly, LI and LII begin to be expressed at a specific point in embryogenesis and appear to be integrated with LIII into a common lamina structure. Later in development, LIII reappears as a prominent nuclear lamina protein but only in certain cells (neurons, muscle cells, and diplotene oocytes). We conclude that amphibian lamins represent a family of proteins expressed in relation to certain programs of cell differentiation.
D000818:Animals; D002454:Cell Differentiation; D004625:Embryo, Nonmammalian / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D034882:Lamins; D008540:Meiosis; D008675:Metamorphosis, Biological; D009132:Muscles / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D009698:Nucleoproteins / Q000032:analysis / Q000096:biosynthesis*; D009865:Oocytes / Q000378:metabolism*; D009866:Oogenesis; D010053:Ovary / Q000254:growth & development / Q000378:metabolism; D014982:Xenopus laevis / Q000196:embryology / Q000254:growth & development* / Q000378:metabolism
D034882:Lamins; D009698:Nucleoproteins