Meiotic maturation of mouse oocytes in vitro: protein synthesis in nucleate and anucleate oocyte fragments

1978 ◽  
Vol 30 (1) ◽  
pp. 251-264
Author(s):  
R.M. Schultz ◽  
G.E. Letourneau ◽  
P.M. Wassarman
Keyword(s):  
Protein Synthesis ◽  
Meiotic Prophase ◽  
Cytochalasin B ◽  
Meiotic Maturation ◽  
In Vitro Protein Synthesis ◽  
Mammalian Oocyte ◽  
Mouse Oocytes ◽  
Meiotic Competence ◽  
Vitro Protein

Nucleate and anucleate fragments of mouse oocytes have been isolated following treatment of fully grown oocytes with cytochalasin B. The nucleate oocyte fragments resume meiosis in vitro, progressing from dictyate of the first meiotic prophase to metaphase II (‘meiotic maturation’), and exhibit all of the changes in protein synthesis normally associated with meiotic maturation of mouse oocytes. The anucleate oocyte fragments also undergo certain of the changes in protein synthesis associated with meiotic maturation, despite the absence of nuclear progression. These results suggest that the acquisition of meiotic competence (i.e. the ability to undergo meiotic maturation) during growth of the mammalian oocyte is due to changes in the quality, rather than the quantity, of cytoplasm and that the reprogramming of protein synthesis during meiotic maturation is directed by RNA templates already present in the cytoplasm. The behaviour of anucleate oocyte fragments is discussed in terms of the proposed role for nucleoplasm in the initiation of changes in protein synthesis during meiotic maturation of mouse oocytes.

The effect of synthetic lysine and methionine on in vitro protein synthesis of weaning pigs

1995 ◽  
Vol 15 (3) ◽  
pp. 429-437 ◽  
Author(s):  
Y.M. Kwon ◽  
K.N. Heo ◽  
Y.J. Choi ◽  
I.K. Han ◽  
J.H. Woo
Keyword(s):  
Protein Synthesis ◽  
In Vitro Protein Synthesis ◽  
Weaning Pigs ◽  
Vitro Protein

[37] In vitro protein synthesis

1991 ◽  
pp. 536-545 ◽  
Author(s):  
Michael J. Leibowitz ◽  
Francis P. Barbone ◽  
Denise E. Georgopoulos
Keyword(s):  
Protein Synthesis ◽  
In Vitro Protein Synthesis ◽  
Vitro Protein

Cytochalasin B-induced pseudo-cleavage of mouse oocytes in vitro. II. Studies of the mechanism and morphological consequences of pseudocleavage

1977 ◽  
Vol 26 (1) ◽  
pp. 323-337
Author(s):  
P.M. Wassarman ◽  
T.E. Ukena ◽  
W.J. Josefowicz ◽  
G.E. Letourneau ◽  
M.J. Karnovsky
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cytochalasin B ◽  
Oocyte Size ◽  
Contractile Ring ◽  
Subsequent Formation ◽  
Mouse Oocytes ◽  
Meiotic Competence ◽  
Scanning Electron

Mouse oocytes are induced by cytochalasin B to undergo ‘pseudocleavage’ in vitro into 2 compartments, only one of which possesses microvilli. It has been found that this particular response to cytochalasin B is related to oocyte size and, possibly, to the acquisition of meiotic competence by the oocyte during its growth phase. Certain of the morphological events which characterize pseudocleavage have been determined using transmission and scanning electron microscopy. These events include: (i) an initial withdrawal of microvilli from the surface of the oocyte, together with the concomitant disappearance of microfilaments normally associated with the microvilli; (ii) the subsequent formation of a pseudocleavage furrow and contractile ring; and (iii) the reappearance of microvilli and associated microfilaments in one of the two resulting oocyte compartments. These changes in surface architecture are reflected in the distribution of fluorescein-conjugated lectins bound to the oocyte surface during pseudocleavage.

Effects of oestradiol, the oestrous cycle and pregnancy on weight, metabolism and cytosol receptors in the uterus of the brush-tail possum (Trichosurus vulpecula)

1986 ◽  
Vol 108 (2) ◽  
pp. 201-210 ◽  
Author(s):  
J. D. Curlewis ◽  
G. M. Stone
Keyword(s):  
Protein Synthesis ◽  
Protein Content ◽  
Corpus Luteum ◽  
Metabolic Activity ◽  
Weight Ratio ◽  
Oestrous Cycle ◽  
Uterine Weight ◽  
In Vitro Protein Synthesis ◽  
Vitro Protein

ABSTRACT Uterine weight, RNA, DNA, protein content, in-vitro rate of protein synthesis, cytosol oestrogen and progesterone receptors were examined after administration of oestradiol to ovariectomized animals and on days 0, 5, 9 and 13 of the non-pregnant cycle and day 13 of pregnancy. In ovariectomized animals, oestradiol increased uterine weight, RNA: DNA and protein: DNA ratios and the concentration of cytosol receptors for oestradiol and progesterone. During the oestrous cycle there was a linear increase in uterine weight and a significant effect of the corpus luteum on the weight of the ipsilateral uterus. Changes in RNA, DNA and protein content between days 0 and 5 were not observed, but between days 5 and 13 RNA: DNA and protein: DNA ratios increased and the DNA: tissue weight ratio decreased. Thus, cellular hypertrophy and/or increased metabolic activity rather than hyperplasia occur over this period, which is coincident with the known rise in plasma progesterone levels. The rate of in-vitro protein synthesis (per unit tissue protein) during the non-pregnant cycle was greatest at day 0. These changes in uterine metabolic activity were associated with alterations in cytosol receptor concentrations for both steroids. Cytosol progesterone receptor concentrations were highest at day 0 after which they declined to a minimum at day 13. Cytosol oestradiol receptor concentrations, however, rose between days 0 and 5 and then declined. Although lutectomy on day 8 of the cycle does not interfere with the development of a histologically normal luteal phase, high peripheral progesterone levels which occur after day 8 in intact animals are associated with major increases in uterine metabolic activity. The unilateral effect of the corpus luteum on uterine weight was associated with a decrease in DNA: g tissue ratio and an increase in rate of in-vitro protein synthesis indicating hypertrophy and/or extracellular accumulation of secreted material as well as enhanced metabolic activity. There was a significant effect of pregnancy on uterine weight at day 13 and this was associated with an increase in DNA content of both uteri. There was a unilateral effect of pregnancy on RNA: DNA ratio and in-vitro rate of protein synthesis, but not on uterine weight. J. Endocr. (1986) 108, 201–210

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