Dynamics of lamin A/C in porcine embryos produced by nuclear transfer.
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.
Lee
Kiho
K
Department of Animal Sciences, Purdue University, West Lafayette, Indiana 47907, USA.
Fodor
William L
WL
Machaty
Zoltan
Z
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
D034904:Lamin Type A; C440308:lamin C