Intracytoplasmic sperm injection in the rat

Zygote ◽  
1998 ◽  
Vol 6 (2) ◽  
pp. 143-147 ◽  
Author(s):  
D. Dozortsev ◽  
T. Wakaiama ◽  
A. Ermilov ◽  
R. Yanagimachi
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Polar Body ◽  
Survival Rates ◽  
Experimental Conditions ◽  
Injection Techniques ◽  
Partial Zona Dissection ◽  
Second Polar Body ◽  
Polar Body Extrusion ◽  
Activation Rates ◽  
Pronuclear Formation

We applied intracytoplasmic sperm injection (ICSI) to the rat comparing three different sperm injection techniques: conventional setup with a sharp needle bearing a spike (method 1), combination of partial zona dissection (PZD) needle and blunt pipette (method 2) and piezo-injection using a blunt pipette (method 3). We also investigated the timing of sperm pronuclear formation after injection. Survival rates after injection were 8%, 24% and 71% for the methods 1, 2 and 3, respectively. All surviving oocytes formed pronuclei by about 6 h after injection. Although the survival and activation rates following sperm injection using piezo-injection were high, the incidence of normal fertilisation, as evidenced by second polar body extrusion and formation of two pronuclei, was only 10%. The vast majority of the zygotes were multinucleated, although most of them subsequently underwent cleavage. Fixation and staining of injected oocytes at different times after injection revealed that replacement of sperm nuclear protamines by histones takes place by 15 min after injection, sperm head swelling occurs within 0.5–1 h after injection and pronuclei become fully developed by 7 h after injection. Although the rate of normal fertilisation in the rat following ICSI was low under the present experimental conditions, the results indicated that direct ICSI using a piezo-driven pipette would be a potentially valuable method of producing rat offspring.

6 EQUINE SPERM INDUCES PRONUCLEAR FORMATION BY INTRACYTOPLASMIC SPERM INJECTION IN BOVINE, SWINE, AND FELINE OOCYTES INDEPENDENTLY OF CHEMICAL ACTIVATION ASSISTANCE

2015 ◽  
Vol 27 (1) ◽  
pp. 95
Author(s):  
M. B. Rodríguez ◽  
A. Gambini ◽  
R. J. Bevacqua ◽  
D. F. Salamone
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Electric Pulse ◽  
Polar Body ◽  
Chemical Activation ◽  
In Vitro Production ◽  
Vitro Fertilization ◽  
Chi Squared ◽  
Second Polar Body ◽  
Pronuclear Formation

Interspecific intracytoplasmic sperm injection (ICSI) is a valuable tool to study early events of fertilization in species for which oocyte availability is reduced. Equine in vitro fertilization remains unsuccessful and ICSI is the technique of choice for the in vitro production of high-value embryos. Therefore, the objective of this study was to evaluate the rate of pronuclear (PN) formation after ICSI with stallion sperm in bovine, swine and feline oocytes with or without chemical activation assistance. Ovaries from cows and pigs were collected at abattoirs whereas gonads from female domestic cats were obtained from ovariectomized animals at veterinary sterilization centers. Cumulus-oocyte complexes were matured in TCM-199 supplemented following standard protocols for each species. ICSI was performed in 100-μL drops of TALP-HEPES, using frozen-thawed semen from one stallion. Spermatozoa were held separate in 3-μL droplets of 7% (vol/vol) polyvinylpyrrolidone, where one of them was immobilized by swiping the injection pipette across its tail, and then injected into the matured oocyte. After ICSI, some oocytes were chemically activated with 5 μM ionomycin for 4 min (cow and cat) or with an electric pulse (sow) followed by 3 h in culture medium to allow extrusion of the second polar body and then exposure to 1.9 mM 6-DMAP solution for 3 h. Embryos were cultured in SOF medium. After 17 h of culture, embryos were stained with propidium iodide to identify the percentage of oocytes activated and with PN. Haploid and diploid parthenogenetic controls were included. Cleavage (48 h after activation) and blastocyst formation (7–8 days) of the partenogenetic control groups were assessed. There were no statistical differences (chi-squared analysis) in PN formation between the activated and nonactivated groups within species. When the activated group was compared between the different species, no differences were observed. However, for the nonactivated group, significant differences were observed between species. The feline oocyte showed the higher percentage of PN and activation, whereas the bovine oocyte exhibited the lower rate of PN formation (cat: 22/27, 81.48%; swine: 19/39, 71.64%; cow:18/63, 43.07%). Our results suggest that the feline oocyte can be used as model to study fertilization events associated with the stallion sperm due to the higher efficiency in supporting PN formation. Our results indicate that the equine sperm is capable of inducing PN formation in these 3 species without further chemical activation assistance.

A combination of calcium ionophore and puromycin effectively produces human parthenogenones with one haploid pronucleus

Zygote ◽  
2001 ◽  
Vol 9 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Koji Nakagawa ◽  
Shuji Yamano ◽  
Hisayo Nakasaka ◽  
Kenji Hinokio ◽  
Midori Yoshizawa ◽  
...  
Keyword(s):  
Polar Body ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Control Group ◽  
Ionophore A23187 ◽  
Cleavage Rate ◽  
Parthenogenetic Activation ◽  
Second Polar Body ◽  
Activation Rates ◽  
Pronuclear Formation

Parthenogenetic activation with various combinations of the calcium ionophore A23187 and protein synthesis or phosphorylation inhibitors was investigated as a means of producing human parthenogenones with one haploid pronucleus. Unfertilised human aged oocytes exposed to 5 μM A23187 for 5 min were treated with 10 μg/ml puromycin (puromycin group, 46 oocytes) or 2 mM 6-dimethylaminopurine (DMAP group, 42 oocytes) for 5 h. Oocytes treated only with A23187 served as a control (control group, 40 oocytes). After washing the oocytes, they were incubated for up to 37 h. Evidence of activation (pronuclear formation) and cleavage was observed 18 h and 42 h after A23187 treatment, respectively. Activation rates in the puromycin and DMAP groups were significantly higher than in the control group (91% (42/46) and 77% (34/44) vs 20% (8/40), p < 0.05, respectively). In the puromycin group, 81% (34/42) of the activated oocytes showed one pronucleus with the second polar body (2ndPB), whereas none (0/34) of the activated oocytes in the DMAP group extruded the 2ndPB. The cleavage rate in the puromycin group was significantly lower than in the DMAP group (38% vs 68%, p < 0.05). The activated oocytes which had one pronucleus with the 2ndPB in the puromycin group showed a haploid set of chromosomes (10/13). In conclusion, the combination of A23187 and puromycin is effective for producing human parthenogenones with one haploid pronucleus.

scholarly journals Mitochondrial activity and cytoskeleton organization in three pronuclei oocytes after intracytoplasmic sperm injection

Zygote ◽  
2018 ◽  
Vol 26 (4) ◽  
pp. 319-325
Author(s):  
Tuğba Kotil ◽  
M. Ertan Kervancıoğlu ◽  
Gülçin Ekter Kanten ◽  
Gülden Tunalı ◽  
Seyhun Solakoğlu
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Intracytoplasmic Sperm Injection ◽  
Mitochondrial Membrane ◽  
Polar Body ◽  
Meiotic Spindle ◽  
Mitochondrial Activity ◽  
Electron Microscopic ◽  
Second Polar Body ◽  
Polar Body Extrusion

SummaryDigyny, the presence of a third pronucleus due to the failure of second polar body extrusion, is problematic after intracytoplasmic sperm injection (ICSI) practices. Mitochondria have critical roles such as production of adenosine triphosphate (ATP) and regulation of Ca2+ homeostasis during oocyte maturation, fertilization and the following development, while the regulation of meiotic spindle formation, chromosome segregation, pronuclear apposition and cytokinesis is closely associated with the cytoskeleton. In this study, mitochondrial membrane potential, distribution of F-actin and γ-tubulin, and the ultrastructure of three pronuclear (3PN) oocytes were investigated. 3PN oocytes after ICSI procedure were taken from patients who were enrolled in assisted reproduction programmes. For mitochondrial membrane potential analysis, fresh oocytes stained with the mitochondrial membrane potential probe JC-1, were evaluated under fluorescence microscopy. The mitochondrial membrane potential of three pronuclear oocytes showed similar results to normal zygotes. γ-Tubulin was stained strongly at the subplasmalemmal domain and microfilaments were localized at the cortical, but not the perinuclear, area. Cytoplasmic halos were moderately or not detected by electron microscopy; lipofuscin granules, degenerated mitochondria, and multilamellated bodies were seen in the ooplasm. Immunohistochemistry and electron microscopic findings suggested that mitochondrial membrane potential has no direct effect on second polar body extrusion. This abnormality can be associated with an altered cytoskeleton due to poor oocyte quality.

Maturation promoting factor in ascidian oocytes is regulated by different intracellular signals at meiosis I and II

Development ◽  
1996 ◽  
Vol 122 (7) ◽  
pp. 1995-2003 ◽  
Author(s):  
G.L. Russo ◽  
K. Kyozuka ◽  
L. Antonazzo ◽  
E. Tosti ◽  
B. Dale
Keyword(s):  
Kinase Activity ◽  
Phase 1 ◽  
Polar Body ◽  
Calcium Transients ◽  
Phase 2 ◽  
Phase 3 ◽  
First Polar Body ◽  
Second Polar Body ◽  
Polar Body Extrusion ◽  
Maturation Promoting Factor

Using the fluorescent dye Calcium Green-dextran, we measured intracellular Ca2+ in oocytes of the ascidian Ciona intestinalis at fertilization and during progression through meiosis. The relative fluorescence intensity increased shortly after insemination in a single transient, the activation peak, and this was followed by several smaller oscillations that lasted for approximately 5 minutes (phase 1). The first polar body was extruded after the completion of the phase 1 transients, about 9 minutes after insemination, and then the intracellular calcium level remained at baseline for a period of 5 minutes (phase 2). At 14 minutes postinsemination a second series of oscillations was initiated that lasted 11 minutes (phase 3) and terminated at the time of second polar body extrusion. Phases 1 and 3 were inhibited by preloading oocytes with 5 mM heparin. Simultaneous measurements of membrane currents, in the whole-cell clamp configuration, showed that the 1–2 nA inward fertilization current correlated temporally with the activation peak, while a series of smaller oscillations of 0.1-0.3 nA amplitude were generated at the time of the phase 3 oscillations. Biochemical characterization of Maturation Promoting Factor (MPF) in ascidian oocytes led to the identification of a Cdc2-like kinase activity. Using p13suc1-sepharose as a reagent to precipitate the MPF complex, a 67 kDa (67 × 10(3) Mr) protein was identified as cyclin B. Histone H1 kinase activity was high at metaphase I and decreased within 5 minutes of insemination reaching a minimum level during phase 2, corresponding to telophase I. During phase 3, H1 kinase activity increased and then decayed again during telophase II. Oocytes preloaded with BAPTA and subsequently inseminated did not generate any calcium transients, nonetheless H1 kinase activity decreased 5 minutes after insemination, as in the controls, and remained low for at least 30 minutes. Injection of BAPTA during phase 2 suppressed the phase 3 calcium transients, and inhibited both the increase in H1 kinase activity normally encountered at metaphase II and second polar body extrusion.

scholarly journals Mitogen-Activated Protein Kinase and Cell Cycle Progression During Mouse Egg Activation Induced by Various Stimuli

1999 ◽  
Vol 54 (3-4) ◽  
pp. 285-294 ◽  
Author(s):  
Q. Y. Sun ◽  
Y. Lax ◽  
S. Rubinstein ◽  
D. Y. Chen ◽  
H. Breitbart
Keyword(s):  
Protein Kinase ◽  
Map Kinase ◽  
Protein Phosphatase ◽  
Kinase Activity ◽  
Polar Body ◽  
Sperm Chromatin ◽  
Mitogen Activated Protein ◽  
Second Polar Body ◽  
Pronuclear Formation ◽  
Mouse Egg

Abstract A very sensitive method was established for detecting the activity of mitogen-activated protein (MAP) kinase in mouse eggs, and used to follow temporal changes of this kinase during fertilization and sponatenous or chemically-induced parthenogenic activation. MAP kinase activity increased between 1 and 2.5 h post-insemination, at which time the second polar body was emitted and sperm chromatin was dispersed; its activity decreased sharply at 8 h, when pronuclei were formed. Both calcium ionophore A23187 and ethanol simulta­ neously induced pronuclear formation and MAP kinase inactivation in aged eggs 8 h after incubation but less effectively in fresh eggs. The protein kinase inhibitor staurosporine in­duced pronuclear formation and MAP kinase inactivation more quickly than other treat­ ments, with MAP kinase inactivation occurring slightly proceeding pronuclear formation. Okadaic acid, a specific inhibitor of protein phosphatase 1 and 2A , induced increase in MAP kinase activity, and overcame pronuclear formation induced by various stimuli. MAP kinase inactivation preceded pronuclear formation in eggs spontaneously activated by aging in vitro, perhaps due to cytoplasmic degeneration and thus delayed response of nuclear envelope precursors to MAP kinase inactivation. These data suggest that MAP kinase is a key protein kinase regulating the events of mouse egg activation. Increased MAP kinase activity is temporally correlated with the second polar body emission and sperm chromatin decondensation. Although different stimuli (including sperm) may initially act through different mechanisms, they finally inactivate MAP kinase, probably by allowing the action of protein phosphatase, and thus induces the transition to interphase.

scholarly journals Cell cycle modification during the transitions between meiotic M-phases in mouse oocytes

1992 ◽  
Vol 102 (3) ◽  
pp. 457-467 ◽  
Author(s):  
J.Z. Kubiak ◽  
M. Weber ◽  
G. Geraud ◽  
B. Maro
Keyword(s):  
Kinase Activity ◽  
Polar Body ◽  
Metaphase Arrest ◽  
Phosphorylated Proteins ◽  
Mouse Oocytes ◽  
Sequence Of Events ◽  
M Phase ◽  
Second Polar Body ◽  
Polar Body Extrusion ◽  
Centrosomal Proteins

When metaphase II-arrested mouse oocytes (M II) are activated very soon after ovulation, they respond abortively by second polar body extrusion followed by another metaphase arrest (metaphase III, M III; Kubiak, 1989). The M II/M III transition resembles the natural transition between the first and second meiotic metaphases (M I/M II). We observed that a similar sequence of events takes place during these two transitions: after anaphase, a polar body is extruded, the microtubules of the midbody disappear rapidly and a new metaphase spindle forms. The MPM-2 monoclonal antibody (which reacts with phosphorylated proteins associated with the centrosome during M-phase) stains discrete foci of peri-centriolar material only in metaphase arrested oocytes; during both transitional periods, a diffuse staining is observed, suggesting that these centrosomal proteins are dephosphorylated, as in a normal interphase. However, the chromosomes always remain condensed and an interphase network of microtubules is never observed during the transitional periods. Incorporation of 32P into proteins increases specifically during the transitional periods. Pulse-chase experiments, after labeling of the oocytes in M phase with 32P, showed that a 62 kDa phosphoprotein band disappears at the time of polar body extrusion. Histone H1 kinase activity (which reflects the activity of the maturation promoting factor) drops during both transitional periods to the level characteristic of interphase and then increases when the new spindle forms. Both the M I/M II and M II/M III transitions require protein synthesis as demonstrated by the effect of puromycin. These results suggest that the two M-phase/M-phase transitions are probably driven by the same molecular mechanism.

Inhibition of protein kinases by 6-dimethylaminopurine accelerates the transition to interphase in activated mouse oocytes

1993 ◽  
Vol 104 (3) ◽  
pp. 861-872 ◽  
Author(s):  
M.S. Szollosi ◽  
J.Z. Kubiak ◽  
P. Debey ◽  
H. de Pennart ◽  
D. Szollosi ◽  
...  
Keyword(s):  
Protein Phosphorylation ◽  
Kinase Inhibitor ◽  
Polar Body ◽  
Histone H1 ◽  
Sperm Chromatin ◽  
Oocyte Activation ◽  
Mouse Oocytes ◽  
Spindle Rotation ◽  
Polar Body Extrusion ◽  
Pronuclear Formation

Mouse oocyte activation is followed by a peculiar period during which the interphase network of microtubules does not form and the chromosomes remain condensed despite the inactivation of MPF. To evaluate the role of protein phosphorylation during this period, we studied the effects of the protein kinase inhibitor 6-dimethylaminopurine (6-DMAP) on fertilization and/or parthenogenetic activation of metaphase II-arrested mouse oocytes. 6-DMAP by itself does not induce the inactivation of histone H1 kinase in metaphase II-arrested oocytes, and does not influence the dynamics of histone H1 kinase inactivation during oocyte activation. However, 6-DMAP inhibits protein phosphorylation after oocyte activation. In addition, the phosphorylated form of some proteins disappear earlier in oocytes activated in the presence of 6-DMAP than in the activated control oocytes. This is correlated with the acceleration of some post-fertilization morphological events, such as sperm chromatin decondensation and its transient recondensation, formation of the interphase network of microtubules and pronuclear formation. In addition, numerous abnormalities could be observed: (1) the spindle rotation and polar body extrusion are inhibited; (2) the exchange of protamines into histones seems to be impaired, as judged by the morphology of DNA fibrils by electron microscopy; (3) the formation of a new nuclear envelope around the sperm chromatin proceeds prematurely, while recondensation is not yet completed. These observations suggest that the 6-DMAP-sensitive kinase(s) is (are) involved in the control of post-fertilization events such as the formation of the interphase network of microtubules, the remodelling of sperm chromatin and pronucleus formation.

The localization of LAP2β during pronuclear formation in bovine oocytes after fertilization or activation

Zygote ◽  
2006 ◽  
Vol 14 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Mamiko Isaji ◽  
Hisataka Iwata ◽  
Hiroshi Harayama ◽  
Masashi Miyake
Keyword(s):  
Chromatin Condensation ◽  
Polar Body ◽  
Somatic Cells ◽  
Histone H3 ◽  
Cumulus Cells ◽  
Polar Bodies ◽  
Second Polar Body ◽  
Pronuclear Formation ◽  
Bovine Oocytes

SummaryWe have shown that the assembly of lamin-associated polypeptide (LAP) 2β was detected surrounding the chromatin mass around the time of extrusion of the second polar body (PB) in some fertilized oocytes, but not in most activated oocytes, by using A23187 and cycloheximide (CaA + CH). Here, we immunohistologically analysed the correlation between LAP2β assembly and chromatin condensation in fertilized and activated oocytes during the second meiosis. In bovine cumulus cells, the onset of LAP2β assembly was observed around anaphase chromosomes with strongly phosphorylated histone H3. No LAP2β assembled around the chromosomes in the first and second polar bodies and the alternative oocyte chromatin (oCh) if histone H3 was phosphorylated. Only histone H3 of oCh was completely dephosphorylated during the telophase II/G1 transition (Tel II/G1), and then LAP2β assembled around only the oCh without phosphorylated histone H3. In the oocytes activated by CaA + CH, LAP2β did not assemble around the condensed oCh during the Tel II/G1 transition, although their histone H3 dephosphorylation occurred rather rapidly compared with that of the fertilized oocytes. The patterns of histone H3 dephosphorylation and LAP2β assembly in oocytes activated by CaA alone showed greater similarity to those in fertilized oocytes than to those in oocytes activated by CaA + CH. These results show that LAP2β assembles around only oCh after complete dephosphorylation of histone H3 after fertilization and activation using CaA alone, and that the timing of histone H3 dephosphorylation and LAP2β assembly in these oocytes is different from that of somatic cells. The results also indicate that CH treatment inhibits LAP2β assembly around oCh but not histone H3 dephosphorylation.

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