Abstract: 262

REMODELING OF CHROMATIN AND CYTOPLASMIC ORGANELLES IN PORCINE ENUCLEATED OOCYTES FOLLOWING INJECTION OF PORCINE OR MOUSE CUMULUS CELLS.

Nam-Hyung Kim^{1 *}
Department of Animal Sciences, Kon Kuk University, Seoul, Korea ¹

In this study we imaged microtubule, mitochondria and chromatin organization in porcine enucleated oocytes following intracytoplasmic injection of porcine or mouse cumulus cells. At 3, 6, 12, 24 and 36 h following injection, the oocytes were permeabilized and fixed. Indirect immunofluorescence was used to detect microtubule organization. DNA was stained with propidium iodide. To detect vital foreign mitochondria, a single mouse or pig cumulus cell, labeled with mitochondria dye MitoTracker, was injected into enucleated oocytes. Either a porcine or a mouse cumulus cell nucleus injected into enucleated oocytes was condensed and formed transient spindle between 3 (39/129, 30%) and 6 h (5/76, 7%), and transformed into pronuclear like structure between 6 (21/76, 28%) and 12 h (83/140, 59%). Self-assembled microtubules were organized from the oocyte cortex, and these seem to move the chromatin to the appropriate position. Treatment of cytochalasin B induced multiple pronuclear like structures (29/41, 71%). Mitochondria introduced into the oocytes by cumulus cell were detected in zygote at least at 36 h following injection. Mitosis and two-cell division were observed at 24 h following injection of porcine cumulus cells (23/207, 11%). These results suggest that either a porcine or a mouse cumulus cell nucleus can be remodeled in enucleated porcine oocytes. The cytoplasmic organelles in enucleated oocytes appeared to interact with foreign nucleus for the reprogramming of nuclear transfer porcine oocytes.

    This abstract is being presented on Monday, August 2 at 8:00 AM to 10:15 AM at CUB 2nd Floor Ballroom.