Beneficial effects of electrical stimulation before round spermatid nuclei injections into rabbit oocytes on fertilization and subsequent embryonic development

Sofikitis, Nikolaos; Toda, Toshiko; Miyagawa, Ikuo; Zavos, Panayiotis M.; Pasyianos, Panayiotis; Mastelou, Efi

doi:10.1016/s0015-0282(16)58048-0

Cited by 66 publications

(46 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…There is indirect evidence that mammalian mature oocytes (with the exception of mouse oocytes) have lost their centrosomic material and that paternally inherited centrosome participates in the mitotic divisions of the zygote (11). In contrast, cleavage of oocytes fertilized by nude nuclear material (i.e., without any cytoplasmic content) extracted from rabbit early spermatids has been demonstrated in three previous studies (1,2,12). In the present study, transmission electron microscopy revealed that the nuclei isolated Fig.…”

Section: Discussionsupporting

confidence: 49%

“…Thus, the fertilization rate after ooplasmic nuclear injections might have been higher if all the nuclei injected were round spermatid nuclei. In animal experiments when a confocal scanning laser microscope-micromanipulator system was used for identification of round spermatids, 97% of the recovered cells were proven to be round spermatids (1,2). It is clear that the method chosen for round spermatid isolation is a major factor affecting the outcome of nuclear injection procedures.…”

Section: Discussionmentioning

confidence: 99%

“…The above two blastocysts were analyzed for chromosomal synthesis. Chromosome spreads were made by a direct preparation (2). Slides were stained with Giemsa (2).…”

Section: Embryo Culturementioning

confidence: 99%

“…Previous studies have shown fertilization and delivery of healthy offspring after transferring round spermatid nuclei into mouse or rabbit oocytes via electrofusion or microsurgical methods, respectively (1)(2)(3). Recently, two human pregnancies have been achieved by ooplasmic injections of intact round spermatid cells (4).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Ooplasmic round spermatid nuclear injection procedures as an experimental treatment for nonobstructive azoospermia

Yamanaka

Sofikitis

Miyagawa

et al. 1997

J Assist Reprod Genet

Self Cite

View full text Add to dashboard Cite

Section: Discussionsupporting

confidence: 49%

Section: Discussionmentioning

confidence: 99%

“…The above two blastocysts were analyzed for chromosomal synthesis. Chromosome spreads were made by a direct preparation (2). Slides were stained with Giemsa (2).…”

Section: Embryo Culturementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Ooplasmic round spermatid nuclear injection procedures as an experimental treatment for nonobstructive azoospermia

Yamanaka

Sofikitis

Miyagawa

et al. 1997

J Assist Reprod Genet

Self Cite

View full text Add to dashboard Cite

“…Moreover, a round spermatid from most mammalian species is lacking in oocyte activation factor; thus, an additional activation procedure is required to allow fertilization following spermatid injection (7)(8)(9). These facts suggest that the timing of spermatid injection and oocyte activation are critical for normal fertilization and embryo development when the conventional ROSI procedure is employed.…”

Section: Introductionmentioning

confidence: 99%

Effects of Activation Timing on the Fertilization Rate and Early Embryo Development in Porcine ROSI Procedure

Choi

Lee

Cheong

et al. 2004

J Assist Reprod Genet

View full text Add to dashboard Cite

Purpose : This study was undertaken to evaluate the optimal exposure time for nuclear envelope breakdown (NEBD) after injection of a round spermatid and to investigate the effect of oocyte activation timing on the fertilization rate and early embryo development in porcine round spermatid injection procedure. Methods : Injected oocytes were fixed at 0.5, 1, 2, 3, and 4 h before activation, and NEBD state was examined. The three groups of oocytes were activated before and after the injection of spermatid using a single direct current pulse (100 V/mm, 50 µs): group 1) at 2 h before the injection (pre), group 2) within 0.5 h after the injection (immediate), and group 3) at 2 h after the injection (post). Activated oocytes were cultured and pronucleus formation and blastocyst development was evaluated at 15-18 h and 7-8 days after the injection, respectively. Results : The proportion of oocytes with NEBD significantly increased in the groups with over 2 h of exposure time ( p < 0.05) and oocyte with premature chromosome condensation began to appear 3 h after the injection. Normal fertilization and development rate to the blastocyst stage were significantly higher in the post group than in those of the pre or immediate group ( p < 0.05). Conclusion : The optimal exposure time for NEBD is 2 h after the injection, and activation in 2 h after round spermatid injection improved the normal fertilization and early embryo development rate.

show abstract

Microtubule and chromatin organization during the first cell-cycle following intracytoplasmic injection of round spermatid into porcine oocytes

et al. 1998

View full text Add to dashboard Cite

The objective of this study was to determine microtubule assembly and chromatin configuration in porcine oocytes during the first cell cycle following round spermatid injection into matured porcine oocytes in the presence or absence of electrical stimulation. The oocytes with two large pronuclei and two polar bodies were classified as normal fertilization at 6 to 8 h following injection. The incidence of normal fertilization following round spermatid injection with electrical stimulation was significantly higher (21/45, 47%) than that following injection alone (6/39, 15%). Although a small microtubular aster was organized near the decondensed spermatid chromatin in some oocytes (2/6, 33%, spermatid injection alone; 9/21, 29%, spermatid injection and electrical stimulation), it did not enlarge nor fill the cytoplasm. Instead, a dense network of microtubules in the cytoplasm was organized from cortex. At 12 to 15 h after injection, we classified the oocytes with closely apposed pronuclei as normal fertilization. The electrical stimulation following spermatid injection enhanced (P < 0.05) the incidence of normal fertilization (18/54, 33%) compared with spermatid injection alone (7/52, 13%). During pronuclear movement, the maternally derived microtubules filled the whole cytoplasm, which appeared to move male and female chromatin. Mitosis and two‐cell division were observed at 20 to 24 h after spermatid injection with electrical stimulation (12/41, 29%). At mitotic metaphase, the microtubular spindle had focused astral poles, and chromosomes were aligned on the spindle equator. During mitosis, asters were assembled at each spindle pole, and they filled the cytoplasm. These results suggested that round spermatid nuclei of the pig can develop into a morphologically normal pronucleus in matured porcine oocytes and are competent to participate in syngamy with the ootid chromatin. In addition, functional microtubules for complete fertilization with spermatid were not associated with male‐derived centrosome but were organized solely from maternal stores. Mol. Reprod. Dev. 50:221–228, 1998. © 1998 Wiley‐Liss, Inc.

show abstract

Beneficial effects of electrical stimulation before round spermatid nuclei injections into rabbit oocytes on fertilization and subsequent embryonic development

Cited by 66 publications

References 19 publications

Ooplasmic round spermatid nuclear injection procedures as an experimental treatment for nonobstructive azoospermia

Ooplasmic round spermatid nuclear injection procedures as an experimental treatment for nonobstructive azoospermia

Effects of Activation Timing on the Fertilization Rate and Early Embryo Development in Porcine ROSI Procedure

Microtubule and chromatin organization during the first cell-cycle following intracytoplasmic injection of round spermatid into porcine oocytes

Contact Info

Product

Resources

About