Timing of sequential changes in chromosome configurations during the second meiotic division and cytoplasmic events of pig oocytes matured and fertilized in vitro

Ocampo, Marlon B.; Ocampo, Lerma C.; Mori, Tadashi; Ueda, Junji; Kanagawa, Hiroshi

doi:10.1016/0378-4320(94)90023-x

Cited by 14 publications

(13 citation statements)

References 18 publications

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“…Our own observations (unpublished data) show that the time of sperm penetration of in vitro-matured oocytes is similar to that of the penetration of immature oocytes. These results are in agreement with those described in the bibliography using pig [38] and bovine [39] oocytes matured and fertilized in vitro. Washing (twice) and preincubation of spermatozoa (40 min) did not accelerate the time needed to penetrate the oocytes, which implies that the spermatozoa are unable to interact immediately with oocytes.…”

Section: Discussionsupporting

confidence: 95%

Oocyte Penetration by Fresh or Stored Diluted Boar Spermatozoa before and after in Vitro Capacitation Treatments1

Rodríguez‐Martínez

Vázquez

Matás

et al. 1996

Biology of Reproduction

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This study examined whether washing and preincubation of boar spermatozoa was necessary to achieve high in vitro penetration rates of pig oocytes. In experiment 1, diluted, sperm-rich fractions, stored for 24 h at 16 degrees C (stored diluted sperm) were used. After centrifugation once at 50 g for 3 min, the supernatant was concentrated at 1200 g for 3 min. The pellets were washed (1200 g for 3 min) 0, 1, or 2 times in saline-BSA solution and preincubated for 0, 20, or 40 min in modified Medium 199 before insemination of immature oocytes. In experiment 2, immature and ovulated oocytes were inseminated with untreated (unwashed and nonpreincubated sperm from concentrated pellet resulting from centrifugation of supernatant fraction obtained by initial low-speed centrifugation) or treated (washed 2 times in saline-BSA solution and preincubated for 40 min), diluted spermatozoa that had been stored and processed as described above. In experiment 3, freshly undiluted or stored diluted spermatozoa were untreated or treated and used to penetrate immature oocytes. In experiment 4, immature oocytes were exposed to freshly undiluted or stored diluted spermatozoa from untreated or treated samples, and, at various times after insemination, oocytes were examined for evidence of penetration. High penetrability rates were obtained when untreated, stored diluted spermatozoa were used. Type of oocyte (immature vs. ovulated) did not affect penetrability regardless of whether untreated or treated, stored diluted spermatozoa were used. Penetration rates and number of spermatozoa per oocyte were lower (p < 0.05) using stored diluted spermatozoa that were washed twice and preincubated 40 min than when freshly undiluted or untreated, stored diluted spermatozoa were used. First evidence of penetration of oocytes by untreated or treated spermatozoa (freshly undiluted or stored diluted) was observed 3 h after insemination. Results indicate that, under the in vitro conditions studied, boar spermatozoa undergoes capacitation and a true acrosome reaction during coincubation with oocytes even when not washed or preincubated.

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Section: Discussionsupporting

confidence: 95%

Oocyte Penetration by Fresh or Stored Diluted Boar Spermatozoa before and after in Vitro Capacitation Treatments1

Rodríguez‐Martínez

Vázquez

Matás

et al. 1996

Biology of Reproduction

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“…Male pronuclear formation in vivo can be observed in the cytoplasm as early as 6 h after mating [26], but it is usually delayed by at least 3 h in porcine oocytes matured and fertilized in vitro [27]. In the first experiment, the addition of 50 liM or 500 VtM cysteamine to the maturation medium significantly increased the incidence of synchronous pronuclear development in both monospermic and polyspermic oocytes.…”

Section: Discussionmentioning

confidence: 97%

Cysteamine Enhances in Vitro Development of Porcine Oocytes Matured and Fertilized in Vitro

Grupen¹,

Nagashima²,

Nottle³

1995

Biology of Reproduction

106

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Most porcine oocytes matured and fertilized in vitro fail to develop normally due to abnormal fertilization. The aim of this study was to determine the effect of cysteamine on pronuclear formation and developmental competence in pig embryos produced in vitro. Follicular oocytes were matured in vitro with or without cysteamine in Medium 199 supplemented with sodium pyruvate, FSH, LH, 17 beta-estradiol, antibiotics, and 25% porcine follicular fluid. Matured oocytes were then inseminated for 10 h. In the first experiment, pronuclear formation was assessed immediately after the insemination period. The addition of 50 microM or 500 microM cysteamine to the maturation medium increased male pronuclear development, resulting in a higher proportion of oocytes with synchronously formed male and female pronuclei. The frequency of synchronous pronuclear formation was increased in monospermic oocytes from 10% in the control group to 43% (p < 0.001) and 45% (p < 0.001), respectively, and in polyspermic oocytes from 43% in the control group to 68% (p < 0.05) and 75% (p < 0.001), respectively. In the second experiment, development of the in-vitro produced embryos was assessed after 7 days of culture in vitro. The addition 500 microM cysteamine to the maturation medium increased the percentage of cleaving embryos developing to the 8-cell (37% vs. 16%; p < 0.001), morula (19% vs. 6%; p < 0.001), and blastocyst (12% vs. 1%; p < 0.001) stages. These results demonstrate that the addition of cysteamine to maturation medium increases synchronous pronuclear formation and normal embryonic development in porcine oocytes matured and fertilized in vitro.

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“…Compared to our results on in vivo maturation of porcine oocytes the maturation of oocytes in vitro is delayed. Oocytes reached M 2 34,4 h to 48 h after IVM (Ocampo et al, 1990). The results about the distribution of polysomal and free mRNA fractions in porcine cumulus cells suggest that cumulus cells became translationally active at late stages of preovulatory maturation without accumulating repressed mRNAs.…”

Section: Discussionmentioning

confidence: 87%

Structural and Functional Changes in Porcine Cumulus‐Oocyte‐Complexes During Preovulatory Maturation

Torner

Brtissow

Tomek

et al. 1998

Reprod Domestic Animals

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ContentsAccording to first results on endoscopical ovum pick up in gilts depending on day of estrous cycle, the aim of our investigation was to determine the influence of the stage of preovulatory maturation in relation to the hCG stimulated LH peak on the morphology of cumulus-oocyte-complexes (COCs) and its influence on the meiotic configuration of oocytes. Furthermore the distribution of active and repressed mRNAs in pig oocytes and cumulus cells depending on stage of preovulatory maturation in vivo were analysed. A total of 45 crossbred Landrace gilts were synchronized for 15 days by RegumateB and 1000 IU PMSG. The endogenous LH peak was simulated by the injection of 500 IU hCG 80 hrs after PMSG. Endoscopic oocyte recovery was carried out 2 h before and 10, 22 and 34 h after the injection of hCG, respectively. Altogether 461 COCs were aspirated and morphologically classified: 25 1 COCs for cytological investigation and 189 COCs for mRNA-analysis. The cumulus morphology of COC populations recovered 2 h before and 10 h after the injection of hCG was very heterogenous. During this time, most of the COCs (80 to 77 %, p

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Timing of sequential changes in chromosome configurations during the second meiotic division and cytoplasmic events of pig oocytes matured and fertilized in vitro

Cited by 14 publications

References 18 publications

Oocyte Penetration by Fresh or Stored Diluted Boar Spermatozoa before and after in Vitro Capacitation Treatments1

Oocyte Penetration by Fresh or Stored Diluted Boar Spermatozoa before and after in Vitro Capacitation Treatments1

Cysteamine Enhances in Vitro Development of Porcine Oocytes Matured and Fertilized in Vitro

Structural and Functional Changes in Porcine Cumulus‐Oocyte‐Complexes During Preovulatory Maturation

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