032. Cdh1: A CELL CYCLE PROTEIN INVOLVED IN FEMALE MEIOSIS AND PREVENTION OF ANEUPLOIDY

2010 ◽  
Vol 22 (9) ◽  
pp. 10
Author(s):  
K. T. Jones
Keyword(s):  
Meiotic Division ◽  
Polar Body ◽  
Single Copy ◽  
Cyclin B1 ◽  
Cell Cycle Protein ◽  
Prophase I ◽  
First Polar Body ◽  
A Cell

Mammalian oocytes are arrested at the dictyate stage of prophase I in the ovary. In growing follicles, oocytes can become responsive to Luteinising Hormone and will undergo meiotic resumption just before ovulation. During the first meiotic division, homologous chromosomes are segregated, a process that is very error prone in human oocytes. By ovulation the oocyte has extruded its first polar body and has re-arrested at metaphase of the first meiotic division. Recent work from our lab has established that the protein Cdh1 is involved uniquely in both in the process of prophase I arrest and the correct segregation of homologs in meiosis I. Thus in cultured oocytes, in vitro antisense knockdown of Cdh1 induces both meiotic resumption and high rates of aneuploidy as a result of non-disjunction during first meiosis. Cdh1 causes prophase I arrest by inducing cyclin B1 degradation and maintaining low levels of the kinase CDK1, whose activity induces meiotic resumption. Cdh1 is an activator of the Anaphase-Promoting Complex (APC), a ubiquitin ligase that earmarks proteins such as cyclin B1 for proteolysis. Cdh1 prevents aneuploidy by causing the degradation of Cdc20, a protein that is responsible for activating the APC once all homologs are correctly aligned at metaphase. Thus loss of Cdh1 seems to prematurely activate APC(Cdc20) activity. It is interesting that a single protein can affect two important meiotic transitions in oocytes. However to explore its functions more fully, and confirm that an in vitro knockdown is faithfully replicated by in vivo loss, a targeted knockout of Cdh1 is needed. Therefore we have generated an oocyte specific Cdh1 knockout by ZP3 promoter driven Cre- recombinase activity in oocytes carrying loxP insertions in the single copy Cdh1 gene. This talk will therefore focus on the effects of an in vivo Cdh1 knockout.

Triphenyltin chloride induces spindle microtubule depolymerisation and inhibits meiotic maturation in mouse oocytes

2014 ◽  
Vol 26 (8) ◽  
pp. 1084 ◽  
Author(s):  
Yu-Ting Shen ◽  
Yue-Qiang Song ◽  
Xiao-Qin He ◽  
Fei Zhang ◽  
Xin Huang ◽  
...  
Keyword(s):  
Polar Body ◽  
Meiotic Maturation ◽  
Dependent Manner ◽  
Germinal Vesicle Breakdown ◽  
Mouse Oocytes ◽  
First Polar Body ◽  
Triphenyltin Chloride ◽  
Dose Dependent

Meiosis produces haploid gametes for sexual reproduction. Triphenyltin chloride (TPTCL) is a highly bioaccumulated and toxic environmental oestrogen; however, its effect on oocyte meiosis remains unknown. We examined the effect of TPTCL on mouse oocyte meiotic maturation in vitro and in vivo. In vitro, TPTCL inhibited germinal vesicle breakdown (GVBD) and first polar body extrusion (PBE) in a dose-dependent manner. The spindle microtubules completely disassembled and the chromosomes condensed after oocytes were exposed to 5 or 10 μg mL–1 TPTCL. γ-Tubulin protein was abnormally localised near chromosomes rather than on the spindle poles. In vivo, mice received TPTCL by oral gavage for 10 days. The general condition of the mice deteriorated and the ovary coefficient was reduced (P < 0.05). The number of secondary and mature ovarian follicles was significantly reduced by 10 mg kg–1 TPTCL (P < 0.05). GVBD decreased in a non-significant, dose-dependent manner (P > 0.05). PBE was inhibited with 10 mg kg–1 TPTCL (P < 0.05). The spindles of in vitro and in vivo metaphase II oocytes were disassembled with 10 mg kg–1 TPTCL. These results suggest that TPTCL seriously affects meiotic maturation by disturbing cell-cycle progression, disturbing the microtubule cytoskeleton and inhibiting follicle development in mouse oocytes.

scholarly journals Deficiency of G9a Inhibits Cell Proliferation and Activates Autophagy via Transcriptionally Regulating c-Myc Expression in Glioblastoma

2020 ◽  
Vol 8 ◽  
Author(s):  
Xiao Xue Ke ◽  
Rui Zhang ◽  
Xi Zhong ◽  
Lei Zhang ◽  
Hongjuan Cui
Keyword(s):  
Cell Proliferation ◽  
Cyclin B1 ◽  
Luciferase Reporter ◽  
Cycle Arrest ◽  
Histone Lysine Methyltransferase ◽  
Lysine Methyltransferase ◽  
A Cell ◽  
Cell Proliferation Control

Glioblastoma is an aggressive and difficult to treat cancer. Recent data have emerged implicating that histone modification level may play a crucial role in glioma genesis. The histone lysine methyltransferase G9a is mainly responsible for the mono- and di-methylation of histone H3 lysine 9 (H3K9), whose overexpression is associated with a more aggressive phenotype in cancer. However, the detailed correlations between G9a and glioblastoma genesis remain to be further elucidated. Here, we show that G9a is essential for glioblastoma carcinogenesis and reveal a probable mechanism of it in cell proliferation control. We found that G9a was highly expressed in glioblastoma cells, and knockdown or inhibition of G9a significantly repressed cell proliferation and tumorigenesis ability both in vitro and in vivo. Besides, knockdown or inhibition of G9a led to a cell cycle arrest in G2 phase, as well as decreased the expression of CDK1, CDK2, Cyclin A2, and Cyclin B1, while it induced the activation of autophagy. Further investigation showed that G9a deficiency induced cell proliferation suppression, and activation of autophagy was rescued by overexpression of the full-length c-Myc. Chromatin immunoprecipitation (ChIP) assay showed that G9a was enriched on the −2267 to −1949 region of the c-Myc promoter in LN-229 cells and the −1949 to −1630 region of the c-Myc promoter in U-87 MG cells. Dual-luciferase reporter assay showed that c-Myc promoter activity was significantly reduced after knockdown or inhibition of G9a. Our study shows that G9a controls glioblastoma cell proliferation by transcriptionally modulating oncogene c-Myc and provides insight into the capabilities of G9a working as a potential therapeutic target in glioblastoma.

74 IN VIVO SURVIVAL OF DOMESTIC CAT OOCYTES AFTER VITRIFICATION, INTRACYTOPLASMIC SPERM INJECTION, AND TRANSFER TO RECIPIENTS

2008 ◽  
Vol 20 (1) ◽  
pp. 118 ◽  
Author(s):  
M. C. Gómez ◽  
N. Kagawa ◽  
C. E. Pope ◽  
M. Kuwayama ◽  
S. P. Leibo ◽  
...  
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Polar Body ◽  
Oocyte Retrieval ◽  
Cumulus Cells ◽  
Domestic Cat ◽  
Minimal Amount ◽  
Vitro Fertilization ◽  
First Polar Body

The ability to cryopreserve female gametes efficiently holds immense economic and genetic implications. The purpose of the present project was to determine if domestic cat oocytes could be cryopreserved successfully by use of the Cryotop method. We evaluated (a) cleavage frequency after in vitro fertilization (IVF) v. intracytoplasmic sperm injection (ICSI) of in vivo- and in vitro-matured oocytes after vitrification, and (b) fetal development after transfer of resultant embryos into recipients. In vivo-matured cumulus–oocyte complexes (COCs) were recovered from gonadotropin-treated donors at 24 h after LH treatment, denuded of cumulus cells, and examined for the presence of the first polar body (PB). In vitro-matured COCs were obtained from ovaries donated by local clinics and placed into maturation medium for 24 h before cumulus cells were removed and PB status was determined. Oocytes were cryopreserved by the Cryotop method (Kuwayama et al. 2005 Reprod. Biomed. Online 11, 608–614) in a vitrification solution consisting of 15% DMSO, 15% ethylene glycol, and 18% sucrose. For IVF, oocytes were co-incubated with 1 � 106 motile spermatozoa mL–1 in droplets of modified Tyrode's medium in 5% CO2/air at 38�C (Pope et al. 2006 Theriogenology 66, 59–71). For ICSI, an immobilized spermatozoon was loaded into the injection pipette, which was then pushed through the zona pellucida into the ooplasm. After a minimal amount of ooplasm was aspirated into the pipette, the spermatozoon was carefully expelled, along with the aspirated ooplasm. After ICSI, or at 5 or 18 h post-insemination, in vivo- and in vitro-matured oocytes, respectively, were rinsed and placed in IVC-1 medium (Pope et al. 2006). As assessed by normal morphological appearance after liquefaction, the survival rate of both in vivo- and in vitro-matured oocytes was >90% (93–97%). For in vitro-matured oocytes, cleavage frequencies after IVF of control and vitrified oocytes were 73% (16/22) and 53% (30/57), respectively, as compared to 68% (19/28) after ICSI of vitrified oocytes (P > 0.05). For in vivo-matured oocytes, cleavage frequencies after IVF of control and vitrified oocytes were 55% (18/33) and 35% (6/17), respectively, compared to 50% (10/20) after ICSI of vitrified oocytes (P > 0.05). At 18–20 h after ICSI, 18 presumptive zygotes and four 2-cell embryos derived from vitrified in vitro-matured oocytes and 19 presumptive zygotes produced from seven in vivo-matured and 12 in vitro-matured vitrified oocytes were transferred by laparoscopy into the oviducts of two recipients at 24–26 h after oocyte retrieval. The two recipients were 9-month-old IVF/ET-derived females produced with X-sperm sorted by flow cytometry. At ultrasonography on Day 22, both recipients were pregnant, with three live fetuses observed in one recipient and one live fetus seen in the second recipient. On Day 63 and Day 66 of gestation, four live kittens were born, without assistance, to the two recipients. The one male and three female kittens weighed an average of 131 g. In summary, in vivo viability of zygotes/embryos produced by ICSI of cat oocytes vitrified by the Cryotop method was demonstrated by the birth of live kittens following transfer to recipients.

228 microRNA REGULATION OF GENES IN BOVINE OOCYTES AND EMBRYOS

2010 ◽  
Vol 22 (1) ◽  
pp. 272
Author(s):  
J. P. Barfield ◽  
G. J. Bouma ◽  
G. E. Seidel Jr
Keyword(s):  
Mirna Expression ◽  
Polar Body ◽  
Prostaglandin F2α ◽  
Defined Medium ◽  
Tight Junction Formation ◽  
First Polar Body ◽  
Lysis Buffer ◽  
Bovine Oocytes

Little is known about expression of microRNA (miRNA) in bovine oocytes and pre-implantation embryos. These molecules likely have an important role in regulating development. For example, differences in quality of oocytes matured in vivo v. in vitro might be due, in part, to altered miRNA expression. In Experiment 1, in vivo-matured COC were collected by transvaginal aspiration of 7 superstimulated cows 21 to 23 h after GnRH injection, given 48 h after prostaglandin F2α and the last of 6 FSH injections given b.i.d. Oocytes aspirated from abattoir ovaries were matured in vitro for 23 h in a chemically defined medium. After vortexing, maturation of both groups of oocytes was confirmed by visualization of the first polar body, and oocytes were snap frozen in mirVana lysis buffer (Applied Biosciences, Foster City, CA, USA). In Experiment 2, in vitro-matured oocytes were generated as described. Subsets were fertilized in vitro or activated parthenogenetically by incubation in 5-μM ionomycin for 5 min followed by 10 μg mL-1 cycloheximide plus 5 μg mL-1 cytochalasin B for 5 h. After 18 h and 12 h, respectively, fertilized and activated oocytes were centrifuged at 10 000 × g for 10 min to enable visualization of pronuclei. Zygotes with 2 polar bodies and 2 pronuclei and parthenotes with 2 pronuclei were snap frozen in mirVana lysis buffer. Total RNA was extracted from 30 pooled oocytes for each replicate using the mirVana MiRNA Isolation Kit (Ambion, Inc., Austin, TX, USA). Reverse transcription of RNA was performed using the QuantiMir RT kit (System Biosciences, Mountain View, CA, USA), and miRNA expression was evaluated by real-time PCR using the Mouse miRNome Profiler plate, which contains primers for 384 miRNA (System Biosciences). Three plates were analyzed for each group (30 oocytes per plate). Changes in relative expression levels were analyzed with a t-test of values normalized to miR-181a, which was consistently expressed in all samples. In Experiment 1, compared with in vitro-matured oocytes, in vivo-matured oocytes had 11-fold higher (P = 0.02) expression of miR-375, which targets numerous genes involved in electron transport chain and oxidative phosphorylation pathways according to the bioinformatic database mirGator. MiR-291a-5p, miR-494, miR-539, and miR-547 were expressed in in vivo-matured oocytes only; the converse was found for miR-575-5p. Results from Experiment 2 are in the table. Major pathways associated with potential targets of the detected miRNA include TGF-beta signaling, Wnt signaling, tight junction formation, DNA replication reactome, steroid biosynthesis, mRNA processing binding reactome, and glutamate metabolism. Several of these candidate miRNA might be important for regulation of bovine oocyte maturation and embryo development. Table 1.Experiment 2: Fold change expression of miRNA

scholarly journals Developmental competence in vivo and in vitro of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection with fresh or frozen-thawed spermatozoa

Reproduction ◽  
2002 ◽  
pp. 455-465 ◽  
Author(s):  
YH Choi ◽  
CC Love ◽  
LB Love ◽  
DD Varner ◽  
S Brinsko ◽  
...  
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Polar Body ◽  
Cumulus Cells ◽  
Fertilization Rate ◽  
Developmental Competence ◽  
Cleavage Rate ◽  
First Polar Body ◽  
Bovine Oocytes

This study was undertaken to evaluate the development of equine oocytes in vitro and in vivo after intracytoplasmic sperm injection (ICSI) with either fresh or frozen-thawed spermatozoa, without the use of additional activation treatments. Oocytes were collected from ovaries obtained from an abattoir and oocytes classified as having expanded cumulus cells were matured in M199 with 10% fetal bovine serum and 5 microU FSH ml(-1). After 24-26 h of in vitro maturation, oocytes with a first polar body were selected for manipulation. Fresh ejaculated stallion spermatozoa were used for the experiment after swim-up for 20 min in sperm-Tyrode's albumen lactate pyruvate. Frozen-thawed spermatozoa from the same stallion were treated in a similar way. Spermatozoa were immobilized and injected into the oocytes using a Piezo drill. Presumptive zygotes were cultured in G1.2 medium for 20 or 96 h after the injection was administered, or were transferred to the oviducts of recipient mares and recovered 96 h later. In addition, bovine oocytes with first polar bodies were injected with the two types of stallion spermatozoa and fixed 20 h after injection to examine pronuclear formation. Fertilization rate (pronucleus formation and cleavage) at 20 h after injection of spermatozoa was not significantly different between fresh and frozen-thawed sperm groups in either equine or bovine oocytes. Pronucleus formation after injection of spermatozoa into bovine oocytes was significantly higher than that for equine oocytes (P < 0.05). There were no significant differences in cleavage rate or average number of nuclei at 96 h between equine oocytes injected with fresh or frozen-thawed spermatozoa. However, embryos developed in vivo for 96 h had a significantly higher number of nuclei in both sperm treatments compared with those cultured in vitro. These results indicate that good activation rates may be obtained after injection of either fresh or frozen-thawed equine spermatozoa without additional activation treatment. Injection of frozen-thawed equine spermatozoa results in similar embryo development to that obtained with fresh equine spermatozoa. In vitro culture of equine zygotes in G1.2 medium results in a similar cleavage rate but reduced number of cells compared with in vivo culture within the oviduct. Bovine oocytes may be useful as models for assessing sperm function in horses.

359 ICSI AND ACTIVATION OF OOCYTES RECOVERED FROM TRANSITIONAL AND CYCLING MARES

2006 ◽  
Vol 18 (2) ◽  
pp. 286 ◽  
Author(s):  
T. Suh ◽  
S. Purcell ◽  
G. Seidel Jr
Keyword(s):  
Growth Factor ◽  
Polar Body ◽  
Follicular Development ◽  
Transitional Period ◽  
Developmental Competence ◽  
Blastocyst Development ◽  
Cleavage Rate ◽  
First Polar Body

Ovarian follicular development in mares during the transitional period before the breeding season leads to an accumulation of antral follicles of various sizes. The quality of oocytes at this stage may be compromized until the first seasonal ovulation. In this study, we evaluated the developmental competence of oocytes recovered from transitional and cyclic mares, and the effect of zygote activation after intracytoplasmic sperm injection (ICSI). A 2 × 2 × 2 factorial experiment consisting of oocytes from transitional and cyclic mares, two follicle sizes (10 to 20 and 20+ mm), and two treatments (control and activated) was conducted. Follicular oocytes of 14 mares were aspirated in March and April (transitional) and May to July (cyclic) five times per each period at 10-day intervals, without use of hCG. Oocytes aspirated from mares were matured in vitro in a defined medium similar to SOF plus FSH, LH, epidermal growth factor (EGF), insulin-like growth factor (IGF), estradiol (E2), prostaglandin (P4) and 10% FCS, for 30 ± 1 h under 5% CO2 in air at 38.5°C; oocytes with a first polar body were used for ICSI. Motile sperm from frozen-thawed semen were used for sperm injection with a piezo-driven pipet. For activation after ICSI, presumptive zygotes were cultured in G1.3 containing 0.02 µM phorbol 12-myristate 13-acetate (PMA) for 2 h, and then in 2 mM 6-dimethylaminopurine (6-DMAP) for 3 h under 6% CO2 in air at 38.5°C. Zygotes were cultured in 50 µL drops of DMEM/F12 containing 10% FCS for 9 days at 38.5°C in 5% CO2/5% O2/90% N2. Medium was replaced every 3 days. Cleavage and blastocyst rates were calculated based on non-degenerating injected oocytes. Data were analyzed by Fisher's exact test. A total of 115 and 78 oocytes were recovered from cyclic and transitional mares. Average maturation rates to MII in the respective groups were 76.5 and 65.4%, respectively (P < 0.07), and those of 10 to 20 and 20+ mm follicle groups were 70.6 and 80.0%, respectively (P > 0.05). The average cleavage rate in cyclic mares was higher than in transitional mares, and that of the activated group averaged over follicle sizes was higher than that of controls (P < 0.05; Table 1); those of 10 to 20 and 20+ mm follicle groups were not different (P < 0.05; Table 1). Blastocyst rates per oocyte within main effects were not different (P < 0.05; Table 1). Oocytes from transitional mares had lower cleavage rates than those of cyclic mares, but blastocyst development was similar. Activation of zygotes clearly improved cleavage rates of in vivo-derived immature equine oocytes after ICSI. Table 1. Main effect means of responses after ICSI

Cytoplasmic maturation of the marsupial oocyte during the periovulatory period

1996 ◽  
Vol 8 (4) ◽  
pp. 509 ◽  
Author(s):  
KE Mate
Keyword(s):  
Zona Pellucida ◽  
Polar Body ◽  
Monodelphis Domestica ◽  
Cortical Granules ◽  
Nuclear Maturation ◽  
Bettongia Penicillata ◽  
Maturation In Vitro ◽  
First Polar Body

During the period immediately before ovulation, the oocytes of most eutherian and marsupial mammals complete the first meiotic maturation division and extrude the first polar body. In marsupials, this phase of nuclear maturation is accompanied by an increase in size of the egg and maturation of cytoplasmic components. Oocytes from at least four marsupial species, Trichosurus vulpecula, Macropus eugenii, Bettongia penicillata and Monodelphis domestica, continue to grow after formation of the follicular antrum and, although the rate of growth slows in larger follicles, it continues into the period immediately before ovulation. The basis of this growth is unknown but may include accumulation of fluid and/or yolk-like material. Maturational changes within the cytoplasm of the oocyte also occur during the periovulatory period, including the accumulation of cortical granules. Differences in the structure of the zona pellucida are also evident between follicular and ovulated eggs; these differences are suggestive of compression of the zona pellucida, but may involve the addition of extra material. These findings suggest that the marsupial oocyte may not achieve complete cytoplasmic maturity until after ovulation; however, their relevance to fertilization and embryonic development require further investigation. Like those of eutherian mammals, marsupial oocytes undergo spontaneous nuclear maturation once removed from the follicular environment, suggesting a basically similar control system. It is not known whether the preovulatory cytoplasmic changes seen in marsupial oocytes matured in vivo also occur during maturation in vitro.

97 POSITION CHANGES IN THE RELATIONSHIP BETWEEN FIRST POLAR BODY AND CHROMOSOME OF GOLDEN HAMSTER OOCYTES

2009 ◽  
Vol 21 (1) ◽  
pp. 149
Author(s):  
L. Y. Wang ◽  
D. X. Li ◽  
Z. Y. Li
Keyword(s):  
Golden Hamster ◽  
Polar Body ◽  
Cumulus Cells ◽  
Golden Hamsters ◽  
First Polar Body ◽  
Experimental Protocols ◽  
The Relationship ◽  
Hyaluronidase 2

The golden hamster represents an attractive species for studying reproductive physiology, oncology, genetics, and virology. In an effort to establish experimental protocols necessary for cloning golden hamsters, positional changes in the relationship between the first polar body (FPB) and chromosomes of golden hamster oocytes were examined under different conditions. 1) Female hamsters (6 weeks of age) superovulated with eCG (30 IU, i.p.) followed by hCG, (30 IU, i.p.) at intervals of 72 h were sacrificed at different times (13.5, 18, and 23 h) following hCG injection. The cumulus–oocyte complexes (COC) were collected from oviducts, and cumulus cells were removed with 0.1% hyaluronidase; 2) The oocytes of 13.5 h after hCG injection, with or without cumulus cells, were collected and cultured in HECM-3 for 5 and 10 h; 3) The COC collected from small vesicular follicles on the ovarian surface 72 h after eCG administration were cultured in HECM-3 supplemented with 5 μg mL–1 of FSH and 5 μg mL–1 of LH for 18 and 23 h. After the above treatments, denuded oocytes were stained with 10 μg mL–1 of Hoechst 33342 and observed on an inverted fluorescence microscope. During observation, the location of the FPB relative to the MII spindle was recorded as the angle (0–30°, 30–90°, 90–180°) between the line from the FPB to the center of the oocyte and the line from the spindle to the center of the oocyte. Oocytes were also stained with 10 μg mL–1 of propidium iodide (PI) before observation. The FPB that stained with PI were considered to be degenerated. All data were statistically analyzed by one-way ANOVA. Our results showed that 82.10% of FPB in oocytes collected at 13.5 h (n = 73) post-hCG were within the zone of 0–30°, which was significantly greater (P < 0.05) than those of oocytes collected at 18 h (n = 50; FPB 46.32%) and 23 h (n = 82; FPB 33.33%) post-hCG. The degenerate percentage of FPB in oocytes (without cumulus) cultured in vitro for 5 h (n = 72) and 10 h (n = 63) was 45 and 63%, respectively; this was significantly greater (P < 0.05) than that of oocytes with cumulus (5 h, n = 46; 32%; 10 h, n = 46; 45%). The percentage of FPB in oocytes matured in vitro for 18 h (n = 36) was 77.94% within the zone of 0–30°, which was significantly greater (P < 0.05) than the 38.83% seen in oocytes cultured in vitro for 23 h (n = 36). In conclusion, the results of this study demonstrate that a change in position of FPB relative to the MII oocyte chromosome is age-dependent in in vivo-matured oocytes. Cumulus cells can protect the FPB of in vitro-cultured oocytes from degeneration but do not significantly affect its change in position. In vitro-matured oocytes age more slowly than those of in vivo maturation and in vitro culture. These results define conditions for changing the FPB position relative to the MII oocyte chromosome and should facilitate the development of cloned golden hamsters as an animal model for human diseases.

372 SPERM ASTER FORMATION AND BLASTOCYST DEVELOPMENT OF IN VIVO-MATURED BOVINE OOCYTES FERTILIZED BY INTRACYTOPLASMIC SPERM INJECTION

2007 ◽  
Vol 19 (1) ◽  
pp. 301 ◽  
Author(s):  
T. Horiuchi ◽  
M. Takenaka ◽  
C. Kani ◽  
C. Emuta ◽  
Y. Ogata ◽  
...  
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Polar Body ◽  
Cumulus Cells ◽  
Blastocyst Development ◽  
Chi Square ◽  
First Polar Body ◽  
Bovine Oocytes ◽  
Sperm Aster

In cattle, activation treatment after intracytoplasmic sperm injection (ICSI) is required to improve cleavage and blastocyst rates (Horiuchi et al. 2002 Theriogenology 57, 1013–1024). The reason why the exogenous activation treatment in bovine ICSI is needed to promote cleavage and blastocyst development is not clear. The objective of this study was to examine the effect of activation treatment on sperm aster formation, cleavage, and blastocyst development of in vivo- and in vitro-matured bovine oocytes following ICSI. In vivo-matured oocytes were collected using transvaginal devices under ultrasound guide at about 29 h after GnRH injection from Japanese Black cows superstimulated with a total 19 mg FSH (Antrin�; Denka Pharmaceutical Co., Kanagawa, Japan) divided into twice daily over 3 days, and treated with 750 �g cloprostenol (Estramate�; Sumitomo Chemical Co., Tokyo, Japan). In a total of 8 aspiration sessions, 131 oocytes were collected; of 116 oocytes with expanded cumulus cells, 84 (72%) had a first polar body and were used for ICSI. On the other hand, in vitro-matured bovine oocytes were prepared by culturing immature follicular oocytes derived from abattoir ovaries. Bull spermatozoa, immobilized by scoring their tails, were injected into in vivo- or in vitro-matured oocytes. At 4 h after ICSI, the oocytes were treated with or without 7% ethanol for 5 min for activation. The injected oocytes were fixed at 8 h after ICSI, and sperm aster formation was examined by using specific antibodies and immunofluorescence microscopy. Data were analyzed by the chi-square test in all experiments. The rate of sperm aster formation in in vivo-matured oocytes was similar regardless of activation treatment (71% vs. 65%), but the rate in in vitro-matured oocytes was significantly (P &lt; 0.05) higher in the group receiving activation treatment than in the non-activation group (57% vs. 19%). Cleavage (88% vs. 88%) and blastocyst rates (59% vs. 47%) of in vivo-matured oocytes after ICSI were also similar, regardless of activation treatment, but cleavage (72% and 20%) and blastocyst rates (19% and 7%) of in vitro-matured oocytes were significantly (P &lt; 0.05) higher in the group receiving activation treatment than in the non-activation group. Moreover, the blastocyst rate of in vivo-matured oocytes was significantly (P &lt; 0.05) higher than the rate in in vitro-matured oocytes. These results show that activation treatment after ICSI of in vivo-matured bovine oocytes is not necessary for cleavage and blastocyst development, and suggest that the necessity of activation treatment in bovine ICSI has relevance to in vitro maturation of bovine oocytes.

Ultrastructure of Baboon Zygotes Produced By Microinjection of Spermatozoa

1985 ◽  
Vol 43 ◽  
pp. 650-651
Author(s):  
T. Caceci ◽  
A.A. Shaikh ◽  
D.C. Kraemer
Keyword(s):  
Polar Body ◽  
Follicular Development ◽  
Male And Female ◽  
Menstrual Cycles ◽  
Follicular Aspiration ◽  
First Polar Body ◽  
Preovulatory Follicles ◽  
Lh Release

Five baboons were treated during seven menstrual cycles with 5.0 mg of FSH-P for five days, starting on either day 3 or day 5 of the cycle. On day 5 of the treatment, the ovaries were examined by laparoscopy to evaluate follicular development. All animals exhibited multiple preovulatory follicles and at that time 100 mg GnRH was administered intramuscularly to induce LH release. Between 24 and 30 hours after injection of GnRH, laparoscopic follicular aspiration was used to collect oocytes. These were matured in vitro (determined by extrusion of the first polar body) and fertilized by microinjection with frozen-thawed baboon spermatozoa. Male and female pronuclei were observed in 32% of the resulting zygotes within 24 hours. These zygotes were compared to a zygote in the same stage that had been fertilized in vivo and obtained by laparoscopy and flushing of the oviduct.

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