Strontium-Induced Activation Regimen for Rat Oocytes in Somatic Cell Nuclear Transplantation.

Kato, Megumi; Hirabayashi, Masumi; Aoto, Toshihiro; Ito, Kazumi; Ueda, Masatsugu; Hochi, Shinichi

doi:10.1262/jrd.47.407

Cited by 28 publications

(37 citation statements)

References 24 publications

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“…Therefore, the relatively low success rate of ROSI we achieved in rats may be explained by the difficulty of obtaining correctly activated oocytes, bec ause rat ooc ytes ar e known to ac tivate spontaneously in vitro after recovery from the oviductal ampullae [48,51,52]. Nevertheless, these experiments at least show that the ROSI technique is applicable in rats.…”

Section: Round Spermatid Injection (Rosi)mentioning

confidence: 90%

“…Furthermore, the presence of a spermatid nucleus could be confirmed at the time of aspiration into an injection pipette with a diameter of 5-6 µm. The oocytes were activated by treatment with 1.25 mM strontium chloride for 20 min before being subjected to ROSI (rat oocytes are more sensitive to strontium treatment than are mouse oocytes [48]), and 3 rat offspring were produced by the transfer of 219 of 263 oocytes into which LAC3 round spermatids frozen-thawed in the presence of 7.5% glycerol had been injected (Table 3) [49]. The transgene was transmitted to 2 of the 3 offspring.…”

Section: Round Spermatid Injection (Rosi)mentioning

confidence: 99%

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Maintenance of Transgenes in Rats: The Contributions of Embryo Cryopreservation and Intracytoplasmic Sperm/Spermatid Injection.

Hochi

Hirabayashi

2002

J. Reprod. Dev.

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Abstract. The maintenance of transgenes in rats is reviewed with special references to embryo cryopreservation (transgene banking) and intracytoplasmic injection of spermatozoa or round spermatids (transgene passage). Production of transgenic rats by pronuclear DNA microinjection is easily performed, particularly using the micro-vibration method. Two-cell stage embryos derived from the mating of transgenic rats with wild-type rats can be successfully cryopreserved by conventional two-step freezing in the presence of 10% dimethylsulfoxide. However, the transmission rates of transgenes into newborn offspring are lower than the 50% which is expected in simple Mendelian inheritance. Furthermore, some transgenic rats are unable to transmit their transgenes to subsequent generations. When the inability of male transgenic rats to transmit the transgene is not associated with mosaicism, microinsemination techniques such as intracytoplasmic sperm injection (ICSI) and round spermatid injection (ROSI) can be used for passage of the transgenes. Our ICSI procedure includes the use of a piezo-driven small-sized injection pipette (2-4 µm in diameter), isolated sperm heads, and freshly ovulated oocytes. In the case of ROSI, round spermatids are injected into Sr 2+ -activated oocytes using a piezo-driven middle-sized pipette (5-6 µm in diameter). These microinsemination techniques can be combined with cryopreservation of sperm and spermatid cells, leading to successful transmission of transgenes carried in male gametes.

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Section: Round Spermatid Injection (Rosi)mentioning

confidence: 90%

Section: Round Spermatid Injection (Rosi)mentioning

confidence: 99%

Maintenance of Transgenes in Rats: The Contributions of Embryo Cryopreservation and Intracytoplasmic Sperm/Spermatid Injection.

Hochi

Hirabayashi

2002

J. Reprod. Dev.

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“…Activated oocytes extruded the second polar body within 90 min of culture, but development became arrested again without formation of a pronucleus [18]. In our previous study, the proportions of spontaneously activated rat oocytes increased with the time elapsed from animal dissociation (5% after 10 min vs. 82% after 1 3 0 m i n ) , b ut n o ne o f t h e o o c y tes d ur i n g subsequent culture cleaved [8]. Puromycin and chloral hydrate have been reported to be potent activators that could trigger pronucleus formation of spontaneously activated rat oocytes [19].…”

Section: Discussionmentioning

confidence: 78%

“…Dev. 48: [243][244][245][246][247][248]2002) egardless of the successful somatic cell nuclear transfer in the sheep [1], mouse [2], cattle [3], goat [4], and pig [5], cloned rats derived from somatic cells have not yet been produced, probably due to poorly understood regimens for nuclear injection and/or oocyte activation [6][7][8]. Hayes et al [6] reported that 65% of rat oocytes treated with ethanol (8%, 5 min) and cycloheximide (35 µM, 4 h) cleaved.…”

Section: +mentioning

confidence: 99%

“…Iannaccone et al [7] reported an activation treatment with strontium chloride (Sr 2+ ; 5 mM, 2.5-3 h) for enucleated rat oocytes receiving cumulus or fibroblast cell nuclei. Recently we also described an activation regimen for rat oocytes using Sr 2+ (1.25 mM, 6 h) in the somatic cell nuclear transfer procedure [8]. Somatic cell nuclei have been injected into enucleated rat oocytes using a piezodriven micromanipulator [6][7][8], as has also been done in cloning of the mouse [2] and pig [5].…”

Section: +mentioning

confidence: 99%

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Effect of Ca2+/Mg2+-free Culture Condition on Spontaneous First Cleavage of Rat Oocytes.

Takeuchi

Kato

Ito

et al. 2002

Journal of Reproduction and Development

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Abstract. The aim of this study was to investigate the effect of Ca 2+ -and Mg 2+ -free culture conditions on induction of spontaneous first cleavage in rat oocytes. Oocytes recovered from superovulated Wistar females 17 h after hCG injection were exposed for 1.5 h to Ca 2+ /Mg 2+ -free, Ca 2+ -free, Mg 2+-free, or control mKRB medium supplemented with 5 µg/ml cytochalasin-B (CB). The oocytes were then cultured for 4.5 h in control medium containing CB and for 28 h in CB-free control medium. The oocytes exposed to the Ca 2+ /Mg 2+ -free medium (23%) cleaved better than those exposed to Ca 2+ -free (8%), Mg 2+ -free (0%), or control (0%) media. The cleavage rates of oocytes recovered 12, 17 and 22 h after hCG injection and exposed to the Ca 2+ /Mg 2+ -free medium were 4, 17 and 22%, respectively. The efficiency of oocyte activation in 1.25 mM Sr 2+ treatment for 6 h was not influenced by the culture background of bivalent cations (cleavage rates: both 49% in Ca 2+ /Mg 2+ -free and Ca 2+ -free medium). These results indicate that Ca 2+ /Mg 2+ -free culture condition induced the spontaneous first cleavage of rat oocytes in an age dependent manner, but had no additional effect on Sr 2+ -induced oocyte activation.

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Possible role of calcium on oocyte development after intracytoplasmic sperm injection in quail (Coturnix japonica)

et al. 2007

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Although a rise in intracellular calcium concentration of vertebrate oocytes plays a pivotal role for the initiation of fertilization or oocyte activation, no study on this subject has been reported in birds. This study was conducted to study the role of intracellular calcium in relation to fertilization in avian oocytes. First, immediately after a quail oocyte was injected with a sperm, it was treated with strontium chloride as an inducer for intracellular calcium rise at doses of 0, 2.5, 5, 7.5, 10 mM for 4 hr in the culture medium and was followed by 20-hr culture. Treatment with 5 mM of strontium chloride induced blastodermal development in 24.2% of injected eggs, although no oocytes developed without strontium treatment. Second, quail oocytes were injected with a sperm and 0.1 M calcium chloride or a sperm and saline solution, cultured without calcium for 4 hr and was followed by 20-hr culture without strontium. The calcium solution induced blastodermal development in 20.5% of the oocytes, although no oocytes developed without calcium treatment. Third, quail oocytes were injected with 1,2-bis (o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (BAPTA) as a calcium chelator, cultured with strontium (5 mM) for 4 hr followed by 20-hr culture without strontium. Only one oocyte developed after BAPTA and strontium treatment of 36 oocytes examined. Developmental stages of all the oocytes ranged from IV to VII. These results suggest that intracellular calcium rise may participate in quail oocyte activation and allow fertilization and blastodermal development.

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Strontium-Induced Activation Regimen for Rat Oocytes in Somatic Cell Nuclear Transplantation.

Cited by 28 publications

References 24 publications

Maintenance of Transgenes in Rats: The Contributions of Embryo Cryopreservation and Intracytoplasmic Sperm/Spermatid Injection.

Maintenance of Transgenes in Rats: The Contributions of Embryo Cryopreservation and Intracytoplasmic Sperm/Spermatid Injection.

Effect of Ca2+/Mg2+-free Culture Condition on Spontaneous First Cleavage of Rat Oocytes.

Possible role of calcium on oocyte development after intracytoplasmic sperm injection in quail (Coturnix japonica)

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