title: Dynamics of lamin A/C in porcine embryos produced by nuclear transfer.
abstract: This study was conducted to investigate the presence of lamin A/C in porcine nuclear transfer embryos and to determine whether lamin A/C can serve as a potential marker for nuclear reprogramming. First, lamin A/C was studied in oocytes and embryos produced by fertilization or parthenogenetic oocyte activation. We found that lamin A/C was present in the nuclear lamina of oocytes at the germinal vesicle stage while it was absent in mature oocytes. Lamin A/C was detected throughout preimplantation development in both in vivo-derived and parthenogenetic embryos. Incubation of the activated oocytes in the presence of alpha-amanitin (an inhibitor of RNA polymerase II), or cycloheximide (a protein synthesis inhibitor) did not perturb lamin A/C assembly, indicating that the assembly resulted from solubilized lamins dispersed in the cytoplasm. In nuclear transfer embryos, the lamin A/C signal that had previously been identified in fibroblast nuclei disappeared soon after fusion. It became detectable again after the formation of the pronucleus-like structure, and all nuclear transfer embryos displayed lamin A/C staining during early development. Olfactory bulb progenitor cells lacked lamin A/C; however, when such cells were fused with enucleated oocytes, the newly formed nuclear envelopes stained positive for lamin A/C. These findings suggest that recipient oocytes remodel the donor nuclei using type A lamins dispersed in the ooplasm. The results also indicate that lamin A/C is present in the nuclear envelope of pig oocytes and early embryos and unlike in some other species, its presence after nuclear transfer is not an indicator of erroneous reprogramming.
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Kiho
authors.initials: K
authors.lastname: Lee
authors.forename: William L
authors.initials: WL
authors.lastname: Fodor
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Machaty
mesh_terms: D000818:Animals; D004628:Embryonic Structures / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D034904:Lamin Type A / Q000032:analysis / Q000378:metabolism*; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000737:chemistry / Q000378:metabolism; D013552:Swine / Q000196:embryology*; D015053:Zygote / Q000737:chemistry / Q000378:metabolism
chemical_list: D034904:Lamin Type A; C440308:lamin C