Influence of combined activation treatments on the success of bovine nuclear transfer using young or aged oocytes

Tanaka, Hozumi; Kanagawa, Hiroshi

doi:10.1016/s0378-4320(97)00070-5

Cited by 31 publications

(18 citation statements)

References 48 publications

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“…This result is contrary to that observed in mammals, where oocyte ageing improves their activation rates, whether normal or parthenogenetic, and is explained as a greater feasibility of aged oocytes to maintain reduced their MPF levels (Escribá and García-Ximénez, 1999). However, in this case the subsequent embryo development can also be penalized (Kaufman, 1981;Stice and Robl, 1988;Collas and Robl, 1990;Tanaka and Kanagawa, 1997). It is possible that the degree of ageing tested in present experiment was somewhat excessive.…”

Section: Discussioncontrasting

confidence: 88%

Electroactivation of zebrafish (Danio rerio) eggs

Cardona-Costa

Pérez-Camps

García-Ximénez

1970

Span. j. agric. res.

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The zebrafish, has recently acquired a complex role in many emerging areas of knowledge, mainly in biomedical research (Nüsslein-Volhard and Dahm, 2002), becoming a new scientific tool in multitude of labs around the world. In this sense, several and varied are the topical areas where the zebrafish has established as a both efficient and capable vertebrate model for developing knowledge. As Streisinger (1986) pointed out, the reasons were their many useful biological characteristics.In zebrafish, egg activation takes place after they are discharged from the ovarian stroma and come into AbstractIn zebrafish, initial egg activation by water after being discharged from the ovarian stroma is followed by normal cleavages only in inseminated eggs. When sperm (genetically active or not) is not used as activating agent, reproductive techniques (as either nuclear transplant or intracytoplasmic sperm injection are ineff icient. In this work, three experiments of egg activation by electric stimuli were performed: In the first, six activation treatments were compared (Voltage × Pulses: 2.76 × 1; 2.76 × 2; 2.76 × 3 and 5.40 × 1; 5.40 × 2; 5.40 × 3). The group 5.40 × 3 showed the best results (32% activated). In the second experiment, an electrical treatment of 20 min was carried out. It consisted in a sequence of three equal electrical stimuli every 10 min (of 1 or 3 consecutive direct current square pulses for 20 µs each and applied at two voltage levels, 2.76 V or 5.4 V). It was observed that the number of pulses negatively affected the rates of damaged and lysed eggs. Moreover, only the 20 min treatment with the combination of 3 consecutive pulses at 2.76 V showed significant differences with their respective control group (43% vs 18% activated eggs, p < 0.05). In the third experiment, negative effects of egg ageing were observed. In conclusion, the best activation treatment for intact (non manipulated) zebrafish eggs concerns sequence B3. The electro-activation stimulus proposed here would be the only one available once the egg has already been activated by water.Additional key words: egg activation; fish; nuclear transplant; oocyte. Resumen Electroactivación de oocitos de pez cebra (Danio rerio)En pez cebra, una vez que los oocitos son descargados del estroma ovárico, su activación inicial por contacto en agua da lugar a divisiones normales únicamente cuando son fertilizados. Cuando no se utiliza semen (inactivado genéticamente o no), las técnicas reproductivas (como transplante nuclear o inyección espermática intracitoplasmática) son ineficientes. En el presente trabajo se desarrollaron tres experimentos de activación oocitaria por estímulos eléctricos: en el primero de ellos, se compararon seis tratamientos de activación (Voltaje × Pulsos: 2,76 × × 1; 2,76 × 2; 2,76 × 3 y 5,40 × 1; 5,40 × 2; 5,40 × 3). El grupo 5,4 × 3 mostró los mejores resultados (32% de activación). En el segundo experimento, se evaluó un tratamiento eléctrico de 20 min de duración. El tratamiento consistió en la aplicación de una secuencia de tre...

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Section: Discussioncontrasting

confidence: 88%

Electroactivation of zebrafish (Danio rerio) eggs

Cardona-Costa

Pérez-Camps

García-Ximénez

1970

Span. j. agric. res.

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“…On the other hand, the use of enucleated and activated oocytes as recipient cytoplasts resulted in an increased frequency of development to the blastocyst stage of embryos reconstituted from unsynchronized donor nuclei from totipotent cell types [19,[30][31][32]. Furthermore, when the synchronized donor cells were transplanted into activated oocytes, the cell stage of the donor blastomeres immediately after division improved the blastocyst formation rate of the NT embryos [12,13]. Thus, in the present study, we used enucleated and activated IVM oocytes as recipient cytoplasts and estimated the suitable IVF embryos as donor embryos for NT.…”

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confidence: 99%

“…Moreover, the development of NT embryos is improved by transplanting the embryonic cells immediately after cell division to the activated recipient oocytes [13,14]. Thus, the cell cycle and cell division status of blastomeres as donor cells for NT may have effects on the development of the resultant NT embryos.…”

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confidence: 99%

Improvement of the Developmental Ability of Nuclear Transfer Embryos by Using Blastomeres from In Vitro Fertilized Embryos Selected According to the Early Developmental Stage and Cell Division Status as Donor Cells in Cattle

Goto

Matoba

Imai

et al. 2011

Journal of Reproduction and Development

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Abstract. This study was conducted to improve the developmental ability of nuclear transfer (NT) embryos by using blastomeres from in vitro fertilized (IVF) embryos with high quality as donor cells. The IVF embryos selected at the 2-cell stage at 24-h postinsemination (hpi) and again at the ≥8-cell stage at 48 hpi (Selected-IVF-embryos) showed the highest blastocyst formation rate among embryos. When blastomeres from the Selected-IVF-embryos (Selected-NT group) or Nonselected-IVF-embryos (Non-selected-NT group) were used as donor cells for NT, the blastocyst formation rate in the Selected-NT group (25.6%) was significantly higher than that in the Non-selected-NT group (13.5%). When blastomeres from the Selected-IVF-embryos at 108 (contained many cells before cell division) and 126 hpi (contained many cells immediately after cell division) were used as donor cells for NT (108-and 126-NT groups, respectively), the 126-NT group showed a significantly higher blastocyst formation rate (32.1%) than the 108-NT group (16.8%). Embryo transfer of blastocysts in the 126-NT group showed that 11 of 23 recipients became pregnant; nine calves were obtained. For the NT embryos reconstructed using in vivo derived embryos, 9 of 20 recipients became pregnant; seven calves were obtained. These results indicate that the blastocyst formation rate of NT embryos can be improved by using blastomeres from IVF embryos selected at the early developmental stage, especially immediately after cell division, and that the resultant NT embryos have a high developmental ability to progress to term that is comparable to NT embryos reconstructed using in vivo derived embryos. Key words: Bovine, Embryo, In vitro fertilization, Nuclear transfer (J. Reprod. Dev. 57: [249][250][251][252][253][254][255] 2011) uclear transfer (NT) technologies are now widely used by numerous laboratories to produce clone animals from embryonic and somatic cells. However, the overall efficiency of clone animal production is influenced by the different sources of donor cells; early pregnancy losses of cattle established from somatic nuclear transfer (sNT) are commonly above 50% [1,2], and the frequency of early fetal mortality is about two times higher with sNT than with embryonic nuclear transfer [3]. Therefore, it can be expected that a higher proportion of transferred NT embryos reconstructed from less-differentiated embryonic blastomeres would result in viable offspring compared with sNT. In addition, the production of embryonic cloned calves is permitted in Japan and food products derived from NT cattle can be on the market, thereby increasing commercial acceptance of the technology. Furthermore, the use of blastomeres from the same embryos for nuclear transfer to produce numerous identical bovine offspring is of great value for multiplication of genotypes having a superior economic value and is expected to contribute to their genetic improvement.In NT technology using embryos at an early developmental stage as donor cells, in vitro fertilized (IVF) embryos are oft...

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“…The activation rate was markedly higher, when calcium ionophore (Liu et al 1998, Suttner et al 2000, Puglisi et al 2003 or ethanol (Yang et al 1994, Tanaka and Kanagawa 1997, Yi and Park 2005 were used in combination with CHX. Moreover, the rate of cleavage and blastocyst formation increases to double percent when two activator substances are used (Rho et al 1998).…”

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confidence: 99%

Artificial Meiotic Arrest and Parthenogenetic Activation of Buffalo Oocytes Using Cycloheximide

2007

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Summary Maintaining oocytes at germinal vesicle (GV) stage without damaging their quality would allow synchronization of maturation and homogenization of the oocyte population. Activation of the oocyte is very important for a number of oocyte or embryo related technologies including intracytoplasmic sperm injection and cloning by nuclear transfer. This work will focus on induction of meiotic inhibition and oocyte activation by cycloheximide (CHX), in buffalo. For this purpose 2 experiments were conducted. In experiment I, buffalo cumulus-oocyte complexes (COCs) were cultured in 100 ml droplets of tissue culture medium 199 enriched with 10% v/v fetal calf serum, FSH and LH (0, 05 iu/ml, PERGOVET 75, Serono, Rome, Italy) and 50 mg/ml gentamycin for 24-26 h at 38.5°C in 5% CO 2 and humidified air for 24 h in the presence of 2 mg/ml CHX. COCs were significantly blocked at the GV stage (20.85% vs. 82.72% in control). Reversibility of the CHX effect was assessed by culturing COCs an additional 24 h in CHX-free culture medium. About 65.0% of treated oocytes (control 80.1%) resumed meiosis and progressed to the MII stage. In experiment II, buffalo oocytes were activated by 10 mM calcium ionophore A23187 for 5 min followed by 10 mg/ml CHX for 3 h. Control oocytes were exposed to conventional in vitro fertilization (IVF) in BO medium. After 48 h of culture, significantly more oocytes (pϽ0.05) were cleaved in the IVF group than in treated group and spontaneous activated one. In conclusion, CHX can be used to block spontaneous resumption of meiosis in buffalo oocytes and its effect is reversible. Also, CHX in combination with calcium ionophore have the ability to induce parthenogenetic activation in buffalo oocytes.

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Influence of combined activation treatments on the success of bovine nuclear transfer using young or aged oocytes

Cited by 31 publications

References 48 publications

Electroactivation of zebrafish (Danio rerio) eggs

Electroactivation of zebrafish (Danio rerio) eggs

Improvement of the Developmental Ability of Nuclear Transfer Embryos by Using Blastomeres from In Vitro Fertilized Embryos Selected According to the Early Developmental Stage and Cell Division Status as Donor Cells in Cattle

Artificial Meiotic Arrest and Parthenogenetic Activation of Buffalo Oocytes Using Cycloheximide

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