Related Experiment Video
Updated: Jun 18, 2026
Mouse Oocyte Microinjection, Maturation and Ploidy Assessment
Published on: July 23, 2011
Fertilizability, developmental competence, and chromosomal integrity of oocytes microinjected with pre-treated
Hiroyuki Watanabe1, Hiroshi Suzuki, Yutaka Fukui
1Department of Food Production Science, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
Abstract:
The aim of the present study was to investigate the safety of sperm pre-treatment during the ICSI procedure using a mouse model. Mouse spermatozoa were treated with methyl-beta-cyclodextrin, lysolecithin, Triton X-100, and dithiothreitol (DTT), and injected into mouse oocytes. The injected oocytes were monitored for chromosomal integrity and pre- and post-implantation development. The chromosomal integrity of the injected oocytes was impaired by in vitro incubation and chemical antagonism. Particularly in the 60-min DTT group, severe chromosome damage increased. Despite the chromosomal damage, the resultant embryos frequently developed to the blastocyst stage. However, the embryos in the 60-min DTT group had significantly higher chromosomal damage and decreased developmental competence to live fetuses. These results indicate that excessive sperm pre-treatment such as DTT for 60 min generates severe chromosome damage in injected oocytes, and that the damage decreases developmental competence to live fetuses but not to blastocysts.
Insights
Excessive sperm pre-treatment, like 60-minute dithiothreitol (DTT) exposure, damages oocyte chromosomes during ICSI. This damage impacts live fetus development but not blastocyst formation in mice.
Area of Science:
- Reproductive Biology
- Developmental Biology
- Genetics
Background:
- Intracytoplasmic sperm injection (ICSI) is a key assisted reproductive technology.
- Sperm pre-treatment methods are used to enhance ICSI success rates.
- The safety and impact of various sperm pre-treatment chemicals on oocyte quality require thorough investigation.
Purpose of the Study:
- To evaluate the safety and effects of specific sperm pre-treatment agents on mouse oocytes.
- To assess the impact of pre-treatment duration on chromosomal integrity and embryonic development post-ICSI.
- To determine the correlation between sperm pre-treatment-induced chromosomal damage and developmental outcomes.
Main Methods:
- Mouse spermatozoa were subjected to pre-treatment using methyl-beta-cyclodextrin, lysolecithin, Triton X-100, and dithiothreitol (DTT).
- Treated spermatozoa were injected into mouse oocytes.
- Oocytes were analyzed for chromosomal integrity, and subsequent embryos were monitored for pre- and post-implantation development.
Main Results:
- In vitro incubation and chemical treatments, particularly 60-minute DTT exposure, led to significant chromosomal damage in injected oocytes.
- Despite chromosomal abnormalities, embryos frequently progressed to the blastocyst stage.
- The 60-minute DTT group exhibited decreased developmental competence, resulting in fewer live fetuses compared to controls.
Conclusions:
- Extended sperm pre-treatment with agents like DTT can induce substantial chromosomal damage in oocytes during ICSI.
- This damage compromises the developmental potential to form live fetuses but does not prevent blastocyst development.
- Optimizing sperm pre-treatment protocols is crucial to minimize oocyte damage and improve ICSI success rates.
