title: In vivo change in the germinal vesicle of the sow oocyte during the follicular phase before the ovulatory LH surge.
abstract: This study describes a morphological change in the germinal vesicle (GV) of the sow oocyte during the follicular phase preceding the ovulatory LH surge. Estrus synchronization obtained with methallibure treatment provided a reference point for dating the onset of the follicular phase of each sow in the experiment. The oocyte GV's of preovulatory follicles having a diameter of less than 2 mm (during the first 2 to 3 days of the follicular phase) showed uniformly dispersed chromatin with no condensation, while the GV's of oocytes from preovulatory follicles of more than 2 mm diameter (from days 2 and 3 of the follicular phase to day 5) presented condensed chromatin in the shape of a crown or horseshoe surrounding the nucleolus, and irregular chromatin clusters in the nucleoplasm; these clusters were usually found lying against the nuclear membrane.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000648:ultrastructure; D004971:Estrus; D004973:Estrus Synchronization; D005260:Female; D007986:Luteinizing Hormone / Q000097:blood*; D008693:Methallibure / Q000494:pharmacology; D008854:Microscopy, Electron; D009865:Oocytes / Q000648:ultrastructure*; D010063:Ovum / Q000648:ultrastructure*; D011247:Pregnancy; D013552:Swine
chemical_list: D007986:Luteinizing Hormone; D008693:Methallibure