Fertilization and blastocyst development in oocytes obtained from prepubertal and adult pigs1

Abstract

Polyspermic fertilization and embryo quality are important issues for the in vitro production of pig embryos. We hypothesized that oocyte donor (prepubertal gilt vs. sow) affects polyspermy and blastocyst development in vitro and that the sexual maturity of the oocyte donor affects the response to sperm concentration in the fertilization medium. In Exp. 1, oocytes of sows and gilts were mounted and stained 12 h after insemination to provide fertilization data. In Exp. 2, putative embryos were developed in vitro to 144 h post-insemination before mounting. In both experiments, cumulus-oocyte complexes (COC) were collected from ovaries of prepubertal gilts and adult sows. Sperm were added after maturation of COC for 40 to 44 h. Sperm from two boars at 0.5 to 5.0 x 10(6) sperm/mL was used for insemination. More (P < 0.01) monospermic fertilizations were observed in oocytes derived from gilts than for oocytes from sows. There were fewer (P < 0.02) penetrated sperm per fertilized oocyte in oocytes from gilts compared with sows. There were effects of semen donor (boar) on the percentage of monospermic (P < 0.01) and polyspermic (P < 0.002) fertilizations, and on the number of penetrated sperm/fertilized oocyte (P < 0.02). In Exp. 2, cleavage and blastocyst formation was evaluated at 2 and 6 d postinsemination, respectively. More (P < 0.001) blastocysts developed from sow-derived oocytes than from gilt-derived oocytes. More (P < 0.05) total cells per blastocyst were observed in embryos from sow-derived oocytes than from gilt-derived oocytes. Semen donor affected the percentage of oocytes cleaving (P < 0.02), and a boar x sperm concentration interaction affected (P < 0.05) the incidence of blastocyt formation. Results indicate that sexual maturity of the donor is not responsible for the high incidence of polyspermy in porcine in vitro fertilization. However, blastocyst development is improved by the use of oocytes from sows rather than from prepubertal gilts.

Effects of the Presence and the Numbers of Corpora Lutea in Non-Delivered and Delivered Pigs on In Vitro Oocyte Maturation and Embryonic Development

“…However, the cell numbers obtained from all groups in this study were comparable with those of blastocysts produced in vitro in previous studies (25.0-74.0) [2,5,6,8] and lower than those of blastocysts produced in vivo (164.5 ± 51.9) [10]. Although, we do not know why these was a difference in the cell numbers of blastocysts examined in the present study, it is clear that we could produce blastocysts with a high proportion keeping comparable quality to those produced in previous studies [2,5,6,8].The intra-oocyte glutathione (GSH) concentration, an indicator of cytoplasmic maturation, has been used for evaluation of formability in male pronuclei (MPN). The MPN formation rates of the three groups, CL0 (50%), CL1-5 (65%) and CL6-10 (74%), showed a stepwise increase (data not shown) along with the CL numbers in the ovary and the P4 levels in FF (Fig.…”

“…The usage of younger oocyte donors enables reduction of the generation interval and rapid expansion of a valuable genotype. In many cases, however, the oocytes obtained from prepubertal animals have had a lower developmental competence than those of postpubertal or aged animals [1,6,8,[14][15][16][17][18]. The low quality of oocytes recovered from prepubertal animals is the principal problem for IVP.…”

“…Dev. 55: [655][656][657][658][659][660] 2009) o date, in vitro production (IVP) of embryos has been attempted in many species including pigs [1][2][3][4][5][6][7][8][9][10][11], cattle [12][13][14][15] and sheep [16,17]. In these trials, the oocytes used for IVP were obtained from animals in various stages of growth, e.g., sexual maturity.…”

Localization of Ubiquitin C-Terminal Hydrolase L1 in Mouse Ova and Its Function in the Plasma Membrane to Block Polyspermy

“…30 However, an exceptionally high incidence of polyspermic fertilization has been revealed in pig fertilization. 31,32 The reasons for this higher incidence of polyspermy in oocytes are not clear, and relatively little is known about the exact mechanisms that prevent polyspermy. The mechanism that prevents polyspermy is classically illustrated by the zona reaction (cortical reaction) and subsequent plasma membrane block.…”

Effects of in vitro maturation of monkey oocytes on their developmental capacity

“…In cattle and pigs, oocytes from prepubertal donors display poor meiotic maturation and embryo development compared to oocytes from adult females (Marchal et al, 2001;Salamone et al, 2001;de Matos et al, 2003;Grupen et al, 2003;Sherrer et al, 2004). Consistent with their lesser meiotic and developmental potential, oocytes from sexually immature females display morphological, biochemical and physiologic alternations or anomalies that could partially account for their reduced competence.…”