Calcium oscillations in mammalian eggs triggered by a soluble sperm protein

Parrington, John; Swann, Karl; Shevchenko, V. I.; Sesay, Abdul Karim; Lai, F. Anthony

doi:10.1038/379364a0

Cited by 363 publications

(200 citation statements)

References 25 publications

Supporting

Mentioning

186

Contrasting

Unclassified

Order By: Relevance

“…It has been reported that sperm introduces a Ca 2+ releasing factor, osilline 35 kd protein at fertilization. This protein induces repeated cytoplasmic Ca 2+ transients at fertilization [29]. While, when blastomeres from 8-cell embryos were used as donor nuclei, majority of the reconstituted embryos arrested at the 2-cell stage.…”

Section: Discussionmentioning

confidence: 99%

Production of Live Young by Serial Nuclear Transfer with Mitotic Stages of Donor Nuclei in Mice.

Kwon

Kono

Nakahara

1997

Journal of Reproduction and Development

View full text Add to dashboard Cite

Abstract. The developmental ability of reconstituted embryos that received nuclei from 2-, 4-and 8-cell embryos at M phase of the cell cycle was examined in vitro and in vivo. After fusion of M phase nuclei with enucleated oocytes, the reconstituted oocytes were artificially activated and cultured with cytochalasin B to achieve formation of two "pronuclei-like nuclei" (PN-like nuclei). To obtain embryos with a diploid set of chromosomes, nuclei from each reconstructed embryo were transferred individually into separate enucleated fertilized 1-cell embryos. These nuclear transplants developed to multicellular stages at higher rates and the number of reconstituted embryos doubled. Of the embryos reconstituted with 2-, 4-, and 8-cell nuclei at M phase, 26 (23/88), 40 (32/ 80) and 4% (5/135) developed to blastocysts, respectively. Live young were produced from blastocysts obtained from reconstituted embryos that received 2-and 4-cell nuclei at M phase, after transfer into recipient females. to be a result of exchanges of nuclear proteins between the nuclear and cytoplasmic compartments [12]. Several nuclear transfer systems have been proposed that produce reconstituted embryos from donor nuclei containing a normal diploid set of chromosomes at different stages of the cell cycle [13,14]. The key is the relational timing between fusion of the donor nucleus with an enucleated oocyte and activation of the oocyte [14,15]. The reconstituted oocytes extrude an extra-polar body after receiving stimuli that induce oocyte activation. To develop, reconstituted oocytes must contain a normal set of diploid chromosomes after fusion with a donor nucleus and activation. We developed an efficient procedure for transplanting G2 phase nuclei into enucleated mouse oocytes. After activation, the oocytes emitted an extra-polar body and formed a normal diploid nucleus. It was revealed that G2 phase nuclei from 2-cell stage C enucleated oocytes, e.g., mice [1,2]; rabbits [3]; cattle [4,5]; pigs [6]; sheep [7]. The transplantation of an interphase nucleus into enucleated metaphase II oocytes leads to the remodeling of the donor nucleus; nuclear envelope breakdown (NEBD) and premature chromosome condensation (PCC). Interphase nuclei transferred into oocytes undergo PCC, which is associated with the spindle apparatus that is induced by the high level of maturation promoting factor (MPF) activity in the oocyte. When reconstituted oocytes receive suitable stimuli for parthenogenetic activation, extrusion of an extra-polar body [1,7], chromatin decondensation and nuclear reformation occur [8][9][10][11]. Nuclear remodeling of the reconstituted oocytes is thought

show abstract

Section: Discussionmentioning

confidence: 99%

Production of Live Young by Serial Nuclear Transfer with Mitotic Stages of Donor Nuclei in Mice.

Kwon

Kono

Nakahara

1997

Journal of Reproduction and Development

View full text Add to dashboard Cite

show abstract

“…Injection of this factor into hamster oocytes has been shown to trigger a series of calcium transient increases identical to those seen at fertilization [52]. Cytosolic sperm extracts also stimulated repetitive calcium oscillations following injection into mouse [53][54][55], cattle [56] and human [57] oocytes. Interestingly, injection of the same porcine sperm extract induced calcium oscillations of high frequency in mouse oocytes and low frequency in cattle oocytes, similar to the patterns of calcium release observed in each species at fertilization [56].…”

Section: Sperm Factor-mediated Signalling Pathwaymentioning

confidence: 99%

Calcium Release at Fertilization: Artificially Mimicking the Oocyte's Response to Sperm.

Grupen¹,

Nottle²,

Nagashima

2002

Journal of Reproduction and Development

View full text Add to dashboard Cite

Abstract. The mechanism of sperm-induced calcium release has been the subject of many studies since the development in the late 1950s of in vitro culture systems that support mammalian fertilization. Despite efforts to elucidate the nature of the signal from the sperm that triggers both the early and late events of oocyte activation, the precise mechanism remains unresolved. Now, with the advent of somatic nuclear transfer technologies, the need to better understand this unique process has been recognised. Nuclear transfer embryos must be induced to commence development artificially because the activating signal from the sperm is absent. The primary activating stimulus is a large increase in the concentration of intracellular-free calcium and numerous physical and chemical treatments have been found to induce calcium changes that initiate the events of oocyte activation. Although live cloned offspring have been produced in a number of species, the overall efficiencies of the nuclear transfer procedures described thus far are unacceptably low and phenotypic anomalies are common. With the aim of improving these efficiencies, researchers are developing artificial activation treatments which induce oocyte responses that mimic those induced by fertilizing sperm. One strategy is to replicate the pattern of calcium change more closely. Another strategy is to couple an activating stimulus with treatments that inhibit maturation (or M-phase) promoting factor (MPF) activity, which regulates meiotic progression in oocytes. This paper reviews what is understood of calcium release at fertilization and describes the treatments that have been used to induce oocyte activation artificially in parthenogenetic and nuclear transfer studies. The relative effectiveness of the strategies employed to mimic the oocyte's response to sperm are discussed. Key words: Oocyte activation, Fertilization, Parthenogenesis, Nuclear transfer (J. Reprod. Dev. 48: 2002) o produce a viable embryo at fertilization, the s p e r m n o t o n l y p r o v i d e s t h e m a l e chromosomal complement, but also the stimulus that initiates development. The mechanism by which the activating signal is transmitted from the sperm to the oocyte is not fully clarified, but it is clear that this signal triggers a large increase in the concentration of intracellular-free calcium. In fertilized sea urchin and Xenopus eggs, the calcium increase takes the form of a propagating wave that originates at the point of sperm attachment and traverses the egg at a velocity of 5 to 10 µm/sec

show abstract

“…Mammalian sperm extracts produce the characteristic repetitive fertilization calcium waves of mouse, human and hamster eggs (Swann 1990(Swann , 1996Homa & Swann 1994). After a false start (Parrington et al 1996;Shevchenko et al 1998), the active component was identified as a novel phospholipase C, PLCz, that was present only in the testis and the sperm (Rice et al 2000;Saunders et al 2002). This entirely specific tissue distribution argues very strongly that PLCz is the activating agent in mammalian fertilization; there is other indirect evidence: PLCz is sequestered into the zygote nucleus as it reforms after fertilization just as the fertilization calcium transients are dying away; if sequestration is prevented, the transients persist (Kono et al 1995;Larman et al 2004;Saunders et al 2007).…”

Section: Initiation and Propagation Of The Fertilization Calcium Wavementioning

confidence: 99%

Calcium signalling in early embryos

Whitaker

2008

Phil. Trans. R. Soc. B

View full text Add to dashboard Cite

The onset of development in most species studied is triggered by one of the largest and longest calcium transients known to us. It is the most studied and best understood aspect of the calcium signals that accompany and control development. Its properties and mechanisms demonstrate what embryos are capable of and thus how the less-understood calcium signals later in development may be generated. The downstream targets of the fertilization calcium signal have also been identified, providing some pointers to the probable targets of calcium signals further on in the process of development.In one species or another, the fertilization calcium signal involves all the known calcium-releasing second messengers and many of the known calcium-signalling mechanisms. These calcium signals also usually take the form of a propagating calcium wave or waves.Fertilization causes the cell cycle to resume, and therefore fertilization signals are cell-cycle signals. In some early embryonic cell cycles, calcium signals also control the progress through each cell cycle, controlling mitosis.Studies of these early embryonic calcium-signalling mechanisms provide a background to the calcium-signalling events discussed in the articles in this issue.

show abstract

Calcium oscillations in mammalian eggs triggered by a soluble sperm protein

Cited by 363 publications

References 25 publications

Production of Live Young by Serial Nuclear Transfer with Mitotic Stages of Donor Nuclei in Mice.

Production of Live Young by Serial Nuclear Transfer with Mitotic Stages of Donor Nuclei in Mice.

Calcium Release at Fertilization: Artificially Mimicking the Oocyte's Response to Sperm.

Calcium signalling in early embryos

Contact Info

Product

Resources

About