In Vitro Fertilization (IVF) in Straws and a Short Gamete Coincubation Time Improves the Efficiency of Porcine IVF

ArticleinReproduction in Domestic Animals 43(6):747-52 · June 2008with31 Reads
DOI: 10.1111/j.1439-0531.2007.00995.x · Source: PubMed
Abstract
The present study was designed to evaluate three different in vitro fertilization (IVF) systems: a straw-IVF system with 10 min of coincubation, a straw-IVF system with 6-h coincubation and the microdrop-IVF system with 6-h coincubation (the traditional IVF system used routinely in most of IVF laboratories) in an attempt to reduce polyspermic penetration (Experiment 1). When the straw-IVF system was tested in combination with two coincubation times, the use of 10 min of coincubation significantly increased (p < 0.001) the penetration rate and the efficiency of fertilization (67.7 +/- 6.4% vs 31.9 +/- 6.5% and 41.5 +/- 2.5% vs 17.6 +/- 2.5% for 10 min and 6 h, respectively), while there were no significant differences in the incidence of monospermy between both systems (64.3 +/- 5.1% and 67.7 +/- 3.4%, for 10 min and 6 h, respectively). The penetration rate in the 6-h microdrop-IVF system was higher (93.8 +/- 3.6%; p < 0.001) compared with the 10-min straw-IVF system (67.7 +/- 6.4%), however, monospermy was severely reduced (25.0 +/- 4.3% vs 67.7 +/- 3.4%, for the 6-h microdrop-IVF system and 10-min straw-IVF system, respectively). The efficiency of the IVF showed similar values between microdrop and 6-h straw-IVF systems, but efficiency was significantly improved (p < 0.05) when the 10-min straw-IVF system was used. Experiment 2 was designed to compare porcine in vitro embryo production in two IVF systems, the 6-h microdrop-IVF system (1000 sperm per oocyte) and 10-min straw-IVF system (30 000 sperm per oocyte). The blastocyst formation rates tended (p = 0.06) to be higher when the 10-min straw-IVF system was used compared with the 6-h microdrop-IVF system. In addition, the number of total cells per blastocyst increased significantly (p < 0.05) in the 10-min straw-IVF system. These results showed that the 10-min straw-IVF system is an effective way to decrease polyspermic penetration, and improve the efficiency of fertilization and the quality of blastocysts in terms of cell number per embryo.

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    • "However, the effectiveness of a brief gamete co-incubation in decreasing polyspermy was shown to be dependent on the sperm:oocyte ratio used [46], which must be optimized according to the effects of boar and/or storage on sperm fertilizing capacity [47] [48]. A more effective approach may be to combine sperm selection procedures, as Alminana et al. [49] demonstrated that using a straw IVF system together with a short gamete coincubation time improved the efficiency of fertilization and the quality of the blastocysts produced. In addition, the use of caffeine to induce capacitation may not be ideal, because other compounds, such as adenosine and fertilizationpromoting peptide, have been shown to stimulate the fertilizing capacity of boar sperm without significantly increasing the incidence of polyspermic penetration [50]. "
    [Show abstract] [Hide abstract] ABSTRACT: The in vitro production of porcine embryos has presented numerous challenges to researchers over the past four decades. Some of the problems encountered were specific to porcine gametes and embryos and needed the concerted efforts of many to overcome. Gradually, porcine embryo in vitro production systems became more reliable and acceptable rates of blastocyst formation were achieved. Despite the significant improvements, the problem of polyspermic fertilization has still not been adequately resolved and the embryo in vitro culture conditions are still considered to be suboptimal. Whereas early studies focused on increasing our understanding of the reproductive processes involved, the technology evolved to the point where in vitro-matured oocytes and in vitro-produced embryos could be used as research material for developing associated reproductive technologies, such as SCNT and embryo cryopreservation. Today, the in vitro procedures used to mature oocytes and culture embryos are integral to the production of transgenic pigs by SCNT. This review discusses the major achievements, advances, and knowledge gained from porcine embryo in vitro production studies and highlights the future research perspectives of this important technology.
    Full-text · Article · Jan 2014
    • "These alternative IVF techniques could moderate the frequency of polyspermy but still not eliminate it completely. In that sense, we have combined the straw IVF system suggested by Li et al. (2003) with a 10-min co-incubation time, leading to increases in monospermy , fertilization efficiency and blastocyst quality compared to a microdrop-IVF system, independent of the sperm:oocyte ratio (Alminãna et al. 2008a). This potentially conveys a great advantage over traditional IVF protocols, because it allows for the use of a wide range of sperm:oocyte ratios to achieve high levels of monospermic fertilization. "
    [Show abstract] [Hide abstract] ABSTRACT: Contents: Recent advances in new technologies to produce cloned and genetically modified pigs involve manipulating oocytes and/or embryos in vitro. Although a great deal of progress has been made, the current IVM-IVF systems still result in major problems: a high rate of polyspermy; and a low development rate and low quality of blastocysts for in vitro compared with the in vivo-produced embryos. This study summarizes recent advancements in IVM-IVF-IVC porcine systems. Recent methods to select monospermic embryos are also discussed. Finally, achievements in vitrification and in somatic cell nuclear transfer are discussed.
    Full-text · Article · Jun 2010
    • "However, the in vitro production of porcine embryos has been limited by low rates of development to the blastocyst stage (Abeydeera and Day 1997; Kikuchi et al. 2002) and their poor quality compared with blastocysts produced in vivo (Wang et al. 1999 ). The low quality of oocytes after in vitro maturation (IVM; Funahashi et al. 1997; Nagai 2001; Kikuchi et al. 2002), increased polyspermy after IVF (Niwa 1993; Abeydeera and Day 1997; Wang et al. 1997a; Abeydeera 2002; Gil et al. 2004 Gil et al. , 2007Almiñana et al. 2005Almiñana et al. , 2007aAlmiñana et al. , 2007b ) and poor developmental ability of embryos produced by IVM–IVF (Abeydeera 2001) are the main reasons for this limited performance, together with the unsuitability of in vitro culture systems (Kikuchi et al. 2002). Successful nuclear maturation of oocytes in vitro is obtained with a high level of repeatability in most current porcine IVF systems. "
    [Show abstract] [Hide abstract] ABSTRACT: In the present study, the effects of retinoid metabolite administration during in vitro maturation (IVM) on oocyte maturation, parameters of in vitro fertilisation (IVF) and embryo development were examined. Varying concentrations of 9-cis retinoic acid (RA; 0, 5, 50 and 500 nm; Experiment 1) and all-trans retinol (ROH; 0, 125, 1250 and 12 500 nm; Experiment 2) were included in the maturation medium. Cumulus-oocyte complexes were matured in vitro and inseminated with frozen-thawed spermatozoa. Presumptive zygotes were cultured for 16 h to assess IVF parameters or for 7 days to assess embryo development and quality. In Experiment 1, the oocyte maturation rate to metaphase II was significantly decreased (P < 0.001), with values below 5%, in the presence of the highest concentration of RA (500 nm). However, 5 and 50 nm RA had no effect compared with control. Treatment with 5 nm RA improved the blastocyst development rate (P < 0.001). In Experiment 2, the oocyte maturation rate did not differ between 125 and 1250 nm ROH treatment groups and control. However, treatment with 12 500 nm ROH was deleterious because no matured oocytes were observed following the treatment. The penetration rate was lower in the group treated with 1250 nm ROH compared with the 125 nm ROH-treated and control groups, but the blastocyst formation rate did not differ among the three groups. In conclusion, 5 nm RA in the IVM medium significantly increased the blastocyst formation rate, suggesting that RA may play an important role during IVM.
    Full-text · Article · Jan 2008
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