Alterations of mammalian oocyte meiosis I with divalent cations and calmodulin

Jagiello, Georgiana; Ducayen, Mercedes B.; Downey, Robert J.; Jonassen, Amy E.

doi:10.1016/0143-4160(82)90011-2

Cited by 30 publications

(21 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, it acts as a co-factor in enzymatic reactions, and induces meiotic maturation of Xenopus oocytes (Belle et al 1986). Furthermore, low concentrations of divalent cations (Mg and Ca), inhibit the resumption of meiosis, and the inhibitory effect of low Mg concentration is greater than that of low Ca (Leibfreid & First 1979, Jagiello et al 1982. In the present study, low Mg and Ca concentrations in the IVM medium impaired developmental competence, but did not affect the progression of nuclear maturation.…”

Section: Discussionmentioning

confidence: 51%

Effects of follicle size and electrolytes and glucose in maturation medium on nuclear maturation and developmental competence of bovine oocytes

Iwata¹,

Hashimoto²,

Ohota³

et al. 2004

Reproduction

View full text Add to dashboard Cite

The concentrations of electrolytes (Na, K, Cl, Mg and Ca) and glucose in small follicle (SF) follicular fluid (SFF) and large follicle (LF) follicular fluid (LFF) from slaughterhouse-derived ovaries were studied. Oocytes were matured in medium based on synthetic oviductal fluid. The effects of various concentrations of electrolytes (Na, K, Ca and Mg) and glucose in the maturation medium on the progression of nuclear maturation and subsequent development were also studied. K in SFF was significantly greater than that in LFF. The Mg concentration in follicular fluid (FF) is 2.0 -2.3 mM, which is greater than the concentration present in medium generally used for culture. The glucose concentration in FF is about 3.5 -3.9 mM and rapidly decreases during the preservation of ovaries. LF oocytes resumed nuclear maturation and progressed to the M2 stage significantly faster than those collected from SF oocytes. In addition, more LF oocytes developed to blastocysts than did SF oocytes. Changing the Na/K ratio in the maturation medium from 16 to 24 did not affect either the progression of nuclear maturation or the rate of development. A low concentration of Mg (0.5 mM) combined with a low Ca concentration (0.5 mM) inhibited the rate of development, but did not affect the progression of nuclear maturation. On the other hand, increasing the Mg concentration to 2.0 mM from 0.5 mM hastened the progression of nuclear maturation and improved the rate of blastulation, irrespective of the Ca concentration. The progression of nuclear maturation was faster and the rate of development was greater with 5.56 mM glucose than with 1.5 mM glucose. The difference in time needed to progress to M2 among the experiment was about 2-3 h. Therefore, prolonging the maturation periods from 21 to 24 h did not change the rate of development. Our results show that the concentrations of Mg and glucose in the maturation medium and the follicle size enveloping the oocyte affect the progression of nuclear maturation and subsequent development. The time requirement for oocytes to reach M2 is strongly related to the developmental competence of the oocytes.

show abstract

Section: Discussionmentioning

confidence: 51%

Effects of follicle size and electrolytes and glucose in maturation medium on nuclear maturation and developmental competence of bovine oocytes

Iwata¹,

Hashimoto²,

Ohota³

et al. 2004

Reproduction

View full text Add to dashboard Cite

show abstract

“…Jagiello et al (1982) showed a partial inhibition of GVBD in cumulus-enclosed mouse oocytes cultured in calcium-deficient medium in the absence of serum or serum albumin, whereas Tombes et al (1992) failed to show an effect of EGTA on GVBD in cumulus-free mouse oocytes. Both groups reported delays in the formation of the meiotic spindle and inhibition of polar body formation.…”

Section: Extracellular Calcium and Meiotic Maturationmentioning

confidence: 99%

“…Given that mouse oocytes rapidly degenerate in the absence of calcium, it is hard to evaluate some of the observations of Jagiello et al (1982) and Tombes et al (1992). Jagiello et al (1982) showed a partial inhibition of GVBD in cumulus-enclosed mouse oocytes cultured in calcium-deficient medium in the absence of serum or serum albumin, whereas Tombes et al (1992) failed to show an effect of EGTA on GVBD in cumulus-free mouse oocytes.…”

Section: Extracellular Calcium and Meiotic Maturationmentioning

confidence: 99%

“…High concentrations of verapamil (Jagiello et al, 1982) or verapamil in the presence of dibutyryl cyclic AMP (Powers and Paleos, 1982) promotes inhibition of spontaneous GVBD in the mouse. Yet in contrast, relatively low doses failed to inhibit spontaneous GVBD in both the mouse (Paleos and Powers, 1981) and the pig (Kaufman and Homa, 1993) oocyte.…”

Section: Extracellular Calcium and Meiotic Maturationmentioning

confidence: 99%

See 1 more Smart Citation

Calcium and meiotic maturation of the mammalian oocyte

Homa

1995

Molecular Reproduction Devel

117

View full text Add to dashboard Cite

The role of calcium in the regulation of both the meiotic and mitotic cell cycles has been the subject of considerable investigation in the nonmammalian field. In contrast, the mechanisms for signalling meiotic maturation in the mammalian oocyte are not as well documented nor as clearly defined. In the mammalian oocyte, calcium is associated with both spontaneous and hormone-induced meiotic maturation.

show abstract

“…Calcium (Ca++) has been implicated as the second messenger or dependent ion in resumption of meiosis in oocytes from swine (Kaufman and Homa, 1993). In the cattle resumption of meiosis was suppressed in medium devoi'd of or deficient in Ca++ (Leibfried and First, 1980;Jagiello et al, 1982) or presence of neomycin, an inhibitor of phosphoinositide hydrolysis (Homa,199 1). In contrast, the culture of some mammalian oocytes in the medium containing calcium modikng reagents does not appear to have any significant effect on their ability to undergo meiotic resumption (Kaufman and Homa, 1993).…”

Section: Introductionmentioning

confidence: 99%