title: Improvement of the developmental competence of porcine oocytes collected from early antral follicles by cytoplast fusion.
abstract: In the present study, we propose an alternative technique called cytoplast fusion to improve the maturation rate and developmental competence of growing oocytes collected from early antral follicles in pigs. We examined whether the fusion of a growing oocyte with the cytoplast from a fully-grown oocyte (CFR group) could better promote maturation and developmental competence of the growing oocyte compared to germinal vesicle (GV) transfer (GVTR group). After 44 h of in vitro maturation (IVM), most growing oocytes (GR group) were still arrested at the GV stage (64.0 ± 5.1%); this number was significantly higher (P < 0.01) than that of the other groups. No matured oocyte was observed in the GR group. The maturation rate of GVTR oocytes was significantly improved (18.8 ± 3.5%) compared with that of growing oocytes. The proportion of oocytes that reached the metaphase-II (M-II) stage in the CFR group (37.8 ± 2.0%) was significantly higher (P < 0.05) than that in the GVTR group, although still lower than that in the control group (75.2 ± 4.4%). No blastocyst was derived from growing oocytes. Among in vitro fertilized GVTR oocytes, 3.0 ± 1.9% developed into blastocysts; however, this percentage showed an insignificant increase compared with the GR group. On the other hand, the percentage of CFR embryos that developed into blastocysts (12.0 ± 4.3%) was significantly higher than that of GR embryos (0.0%), although still lower than that of control embryos (27.0 ± 5.5%). Total cell number in blastocysts in the GVTR group (23.3 ± 6.9) was significantly lower (P < 0.05) than that in the control group (50.4 ± 5.0). Meanwhile, the total cell number in blastocysts derived from CFR oocytes (36.3 ± 4.8) was comparable to that of the control group. In summary, cytoplast fusion significantly improves maturation rate and developmental competence of growing oocytes compared with GV transfer.
authors: Division of Animal Science, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Ibaraki 305-8602, Japan.
authors: Thanh Quang
authors: TQ
authors: Dang-Nguyen
authors: Ruth
authors: R
authors: Appeltant
authors: Tamas
authors: T
authors: Somfai
authors: Shinya
authors: S
authors: Ishihara
authors: Nguyen Thi
authors: NT
authors: Men
authors: Elisa Caroline da Silva
authors: EC
authors: Santos
authors: Junko
authors: J
authors: Noguchi
authors: Hiroyuki
authors: H
authors: Kaneko
authors: Kazuhiro
authors: K
authors: Kikuchi
mesh_terms: D000818:Animals; D001562:Benzimidazoles / Q000737:chemistry; D001755:Blastocyst / Q000166:cytology; D002467:Cell Nucleus; D003593:Cytoplasm / Q000378:metabolism*; D005260:Female; D005307:Fertilization in Vitro; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods*; D008677:Metaphase; D009865:Oocytes / Q000166:cytology*; D009866:Oogenesis; D006080:Ovarian Follicle / Q000166:cytology* / Q000378:metabolism; D010053:Ovary / Q000378:metabolism; D013552:Swine
chemical_list: D001562:Benzimidazoles; C017807:bisbenzimide ethoxide trihydrochloride