Delayed sperm incorporation into parthenogenetic mouse eggs: Sperm nucleus transformation and development of resulting embryos

Maleszewski, Marek; Borsuk, Ewa; Koziak, Katarzyna; Maluchnik, Darek; Tarkowski, Andrzej

doi:10.1002/(sici)1098-2795(199911)54:3<303::aid-mrd11>3.0.co;2-0

Cited by 21 publications

(6 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, exposing golden hamster oocytes to a calcium ionophore enhances the formation of male pronuclei (10). Furthermore, mouse embryos produced by ICSI after parthenogenetic stimulus with ethanol developed to full-term (11). Although the combination of ICSI and parthenogenetic activation is thus promising for assisted reproduction, the possibility of chromosome aberrations remains a concern.…”

Section: Introductionmentioning

confidence: 99%

How Long Do Parthenogenetically Activated Mouse Oocytes Maintain the Ability to Accept Sperm Nuclei as a Genetic Partner?

Tateno

Kamiguchi

2005

J Assist Reprod Genet

View full text Add to dashboard Cite

Purpose : Cytogenetic risk of intracytoplasmic sperm injection (ICSI) after artificial oocyte activation (post-activation ICSI) was evaluated in the mouse. Methods : Mouse zygotes were produced by ICSI into eggs at various intervals after parthenogenetic exposure to strontium (Sr) for 30 min. Male pronucleus formation and the chromosome constitution were studied. Results : Sperm nuclei injected into oocytes within 1 h after Sr exposure (from early through mid-telophase) transformed normally into male pronuclei, and the number of chromosome aberrations did not significantly increase in the resultant zygotes. When sperm nuclei were injected into eggs at intervals beyond 1 h after Sr exposure (from late telophase through the G 1 pronuclear stage), the rate of male pronucleus formation was significantly reduced. The incidence of chromosome aberrations increased with time between oocyte activation and ICSI. Conclusions : ICSI into oocytes within 1 h after parthenogenetic activation produces cytogenetically competent embryos in the mouse.

show abstract

Section: Introductionmentioning

confidence: 99%

How Long Do Parthenogenetically Activated Mouse Oocytes Maintain the Ability to Accept Sperm Nuclei as a Genetic Partner?

Tateno

Kamiguchi

2005

J Assist Reprod Genet

View full text Add to dashboard Cite

show abstract

“…Transformation of both female and male chromatin during this phase may be crucial for proper regulation of parental imprinting. Previous experiments have demonstrated that male chromatin is able to form a functional pronucleus in the second rather than the first cell cycle, however, is unable to support development to term (Plusa et al, 1997;Maleszewski et al, 1999). No study has previously been performed to investigate whether female chromatin in the form of a metaphase plate of the second meiotic division can form a The differences between the groups (anaphase vs. anaphase/ telophase, for full sized and underdeveloped nuclei), as calculated using w 2 test, are statistically significant at P < 0.001 (1 degree of freedom).…”

Section: Discussionmentioning

confidence: 98%

Meiotic maternal chromosomes introduced to the late mouse zygote are recruited to later embryonic divisions

et al. 2005

View full text Add to dashboard Cite

The aim of this study was to investigate the fate of an additional female genome introduced to a dividing zygote. Maternal chromatin in the form of karyoplasts containing a metaphase II spindle were fused to zygotes blocked in anaphase or telophase of the first cleavage. Permanent preparations made 20-40 min after fusion at anaphase revealed that the donor maternal chromosomes had entered anaphase or telophase in 16 out of 18 cases. A further two groups of embryos that were fused at either anaphase or anaphase/telophase were cultured to the first division. Division occurred 50 min after fusion in both groups of embryos (86 and 85.1%, respectively), of which most divided to two cells (80 and 71.6% of total) and the remainder divided to three cells. About two thirds of two-cell embryos contained an extra nucleus in one blastomere. Nuclei containing donor maternal chromosomes reached a similar size to recipient nuclei in 68% of embryos derived from anaphase-blocked zygotes, in contrast to 31.1% of embryos derived from anaphase/telophase-blocked embryos. Replication of DNA in donor nuclei closely followed the timing and intensity of that in control embryos. When fixed 24 hr after fusion, one third of embryos were still at the two-cell stage, with one or both blastomeres showing a single metaphase plate of the second cleavage. In the remaining embryos, three or four cells were present, some containing two nuclei. Blastocysts developed in 50% of fused embryos and three young were born after transfer of cleaving hybrid embryos to recipients. Chromosome preparations from bone marrow of the young contained 3-4 tetraploid metaphase plates per several hundred plates counted compared with none in control embryos. In conclusion, additional maternal chromosomes can be introduced at the late-dividing zygote and join the embryonic cell cycles during subsequent divisions. This method may provide a useful approach for studying changes specific to the maternal genome during early cell cycles of the mammalian embryo.

show abstract

“…In addition, it was also reported that round spermatids injected 1 h after oocyte activation failed to undergo NEBD and their nuclei remained small (10,11). Finally, the increasing time interval between activation and insemination was known to dramatically decrease the ability of oocytes to promote the transformation of sperm nucleus into a fully formed male pronucleus in mouse (24) and pig (25), which may offer an additional explanation for the poor result in the preactivation group.…”

Section: Discussionmentioning

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

Delayed sperm incorporation into parthenogenetic mouse eggs: Sperm nucleus transformation and development of resulting embryos

Cited by 21 publications

References 26 publications

How Long Do Parthenogenetically Activated Mouse Oocytes Maintain the Ability to Accept Sperm Nuclei as a Genetic Partner?

How Long Do Parthenogenetically Activated Mouse Oocytes Maintain the Ability to Accept Sperm Nuclei as a Genetic Partner?

Meiotic maternal chromosomes introduced to the late mouse zygote are recruited to later embryonic divisions

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

Contact Info

Product

Resources

About