Thermostability of Sperm Nuclei Assessed by Microinjection into Hamster Oocytes1

Yanagida, Kaoru; Yanagimachi, Ryuzo; Perreault, Sally D.; Kleinfeld, Ruth G.

doi:10.1095/biolreprod44.3.440

Cited by 103 publications

(60 citation statements)

References 12 publications

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“…From this point of view, in the case of ICSI, chromatin status, especially thiol condition of sperm nuclei, can influence the process of fertilization and subsequent in vitro embryo development. It was suggested by using B6D2F1 mice that immature sperm nuclei with fewer disulfide bonds exhibited relatively faster decondensation and pronuclear formation after ICSI (data not shown), which is consistent the literature previously reported [32]. The ratio of inner cell mass (ICM), which was an index of embryo development, was also assessed during blastocyst formation.…”

Section: Discussionsupporting

confidence: 87%

Embryo development after intracytoplasmic sperm injection can be predicted by assessment of sperm nuclear chromatin

Takayama

Katayose

Sato

2009

Reprod Medicine & Biology

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Purpose To assess the influence of structural differences in sperm nuclei on embryo development in intracytoplasmic sperm injection (ICSI). Methods Semen obtained from forty-four infertile patients who underwent ICSI was examined. In assessing blastocyst development, only those patients who had successfully obtained over five fertilized eggs were included to exclude any oocyte factors (n = 22). Spermatozoa were assessed using excitation fluorescence flow cytometry with acridine orange and the sperm chromatin dispersion (SCD) test. Results There was a significant positive correlation between the COMP values obtained from flow cytometry and blastocyst formation. (r = 0.477, p = 0.025). There was a significant negative correlation between the SCD values representing DNA fragmentation and blastocyst formation. (r = 0.796, p \ 0.001). COMP values and SCD values were independent parameters to assess sperm nuclear quality regarding embryo development in vitro (r = 0.224, p = 0.080). Conclusion Results suggest that injection of spermatozoa with fewer disulfide bonds and less nuclear DNA fragmentation could achieve better blastocyst formation in human ICSI. Assessment of sperm chromatin should help to predict embryo development after ICSI.

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Section: Discussionsupporting

confidence: 87%

Embryo development after intracytoplasmic sperm injection can be predicted by assessment of sperm nuclear chromatin

Takayama

Katayose

Sato

2009

Reprod Medicine & Biology

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“…The oocytes with second polar bodies were recorded activated. Some oocytes were compressed between a slide and coverslip, fixed briefly with 2% glutaraldehyde, stained with acetocarmine, and mounted in acetic glycerol to reconfirm the number and state of pronuclei (17). Some other oocytes were cultured in vitro for 3 or more days to see whether they continue to survive.…”

Section: Methodsmentioning

confidence: 99%

Incorporation of the acrosome into the oocyte during intracytoplasmic sperm injection could be potentially hazardous to embryo development

Morozumi

Yanagimachi

2005

Proc. Natl. Acad. Sci. U.S.A.

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In mice and humans, a normal offspring can be obtained by injecting a single spermatozoon into an oocyte, the process called intracytoplasmic sperm injection (ICSI). When three or more mouse spermatozoa with intact acrosomes were injected into individual mouse oocytes, an increasing proportion of oocytes became deformed and lysed. Oocytes did not deform and lyse when acrosome-less spermatozoa were injected, regardless of the number of spermatozoa injected. Injection of more than four human spermatozoa into a mouse oocyte produced vacuole-like structures in each oocyte. This vacuolation did not happen when spermatozoa were freed from acrosomes before injection. Hamsters, cattle, and pigs have much larger acrosomes than the mouse or human. Injection of a single acrosome-intact hamster, bovine, and porcine spermatozoon deformed and lysed many or all mouse oocytes. This deformation did not happen when these spermatozoa were freed from acrosomes before ICSI, regardless of the number of spermatozoa injected. Because trypsin and hyaluronidase mimicked the action of acrosome-intact spermatozoa, it is likely that the acrosomal enzymes deform and lyse the oocytes. Injection of small amounts of trypsin and hyaluronidase into normally fertilized mouse eggs disturbed their pre-and postimplantation development. In view of potentially harmful effects of acrosomal enzymes on embryo development, the removal of acrosomes before ICSI is recommended for animals with large sperm acrosomes. The removal of acrosomes may increase the efficiency of ICSI in these animals. Although human and mouse spermatozoa do not need to be freed from acrosomes, the removal of acrosomes before ICSI is theoretically preferable. assisted fertilization ͉ bovine ͉ human ͉ mouse ͉ porcine

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“…ICSI oocytes were maintained at 37°C, examined every 30 min, fixed, and stained (37) to verify the completion of the meiotic divisions of oocytes. As the second indication of oocyte activation, the onset of intracellular Ca 2ϩ rises after ICSI was determined.…”

Section: Preparation Of Spermatozoamentioning

confidence: 99%

Simultaneous removal of sperm plasma membrane and acrosome before intracytoplasmic sperm injection improves oocyte activation/embryonic development

Morozumi

Shikano

Miyazaki

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

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Direct injection of a single spermatozoon into an oocyte (ICSI) can produce apparently normal offspring. Although the production of normal offspring by ICSI has been successful in mice and humans, it has been less successful in many other species. The reason for this is not clear, but could be, in part, due to inconsistent activation of oocytes because of delayed disintegration of sperm plasma membrane within oocytes and incorporation of the acrosome containing a spectrum of hydrolyzing enzymes. In the mouse, the removal of sperm plasma membrane and acrosome was not a prerequisite to produce offspring by ICSI, but it resulted in earlier onset of oocyte activation and better embryonic development. The best result was obtained when spermatozoa were demembranated individually immediately before ICSI by using lysolecithin, a hydrolysis product of membrane phospholipids.mouse ͉ human ͉ Ca 2ϩ oscillations ͉ fertilization ͉ lysolecithin D irect injection of a single spermatozoon into an oocyte, commonly called intracytoplasmic sperm injection (ICSI), can produce apparently normal offspring even though it bypasses a number of biological processes necessary for normal fertilization. As long as the sperm nucleus has intact genetic integrity, ICSI can produce healthy offspring regardless of concentrations, morphology, and motility of spermatozoa (1, 2). Only one genomically normal spermatozoon is needed to fertilize one oocyte. A salient difference between natural and ICSI fertilization is that, in the latter, the sperm plasma membrane as well as acrosome (which contains a spectrum of powerful hydrolyzing enzymes) are introduced into an oocyte. For species with small acrosomes, injection of the acrosome into an oocyte apparently does not produce serious problems, but for species like the hamster, with very large acrosomes, injection inevitably results in death of the oocyte (3). We had demonstrated that the contents of the acrosome are potentially harmful to oocytes (4). A notable difference between normal and ICSI fertilization is that repetitive transient increases in intracellular Ca 2ϩ concentration of the oocyte (Ca 2ϩ oscillations), the pivotal signal for oocyte activation (5-8), begins much more slowly in ICSI oocytes than in normally fertilized oocytes. In the mouse, for instance, Ca 2ϩ oscillations begin 1-3 min after plasma membrane fusion between a fertilizing spermatozoon and an oocyte (9), whereas oscillation begins 15-30 min after ICSI (10, 11). In human oocytes, Ca 2ϩ oscillations start 4-12 h after ICSI, when a plasma membrane-intact spermatozoon is injected after immobilization by touching the terminal part of the tail (12). Ca 2ϩ oscillations begin faster (14 Ϯ 6 min) when a spermatozoon is immobilized by applying several piezo pulses to the proximal one-third of the sperm tail before injection (13). Kasai et al. (14) reported that oocyte activation, assessed by the completion of meiosis, occurred earlier when spermatozoa were freed from the plasma membrane before ICSI. Increased fertilization rates aft...

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Thermostability of Sperm Nuclei Assessed by Microinjection into Hamster Oocytes1

Cited by 103 publications

References 12 publications

Embryo development after intracytoplasmic sperm injection can be predicted by assessment of sperm nuclear chromatin

Embryo development after intracytoplasmic sperm injection can be predicted by assessment of sperm nuclear chromatin

Incorporation of the acrosome into the oocyte during intracytoplasmic sperm injection could be potentially hazardous to embryo development

Simultaneous removal of sperm plasma membrane and acrosome before intracytoplasmic sperm injection improves oocyte activation/embryonic development

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