| dc.description.abstract | In this research, I investigated the expression of the histone phosphorylation on serine 28
of H3 (H3S28P) and heterochromatin protein 1 (HP1) during preimplantation
development. In the first experiment, I demonstrated that I could perform Intra cytoplasmic Sperm Injection (ISCI) and produce blastocysts with a success rate of 31.4%.
Secondly, by using immunofluorescence staining I examined the expression of H3S28P
from 1-cell to the blastocyst stage. The result showed that in zygotes, H3S28
phosphorylation was detected in both male and female pronuclei with high expression
around the nucleoli. Besides H3S28P dots in the nucleoplasm, embryos at the 2-cell and
4-cell stages exhibited signals around nucleoli, especially H3S28P accumulations in 4-
cell embryos were larger. From the 8-cell to blastocyst stage, it was no longer found in
nucleoli and only formed dots in the nucleoplasm. Intriguingly, the level of H3S28P in
morula and blastocysts was lower than in its earlier stages. Lastly, I investigated the
expression of HP1 from the zygote to the morula stage. Our data showed that at the 1-cell
stage, HP1 was found in both male and female pronuclei with highly expressed around
the nucleoli. However, maternal nucleoli exhibited higher HP1 expression than paternal
nucleoli. In 2-cell embryos, besides appearing with high signals around nucleoli, HP1
appeared as dots in the nucleoplasm. By the 4-cell stage, HP1 disappeared from nucleoli
and formed large dots in the nucleoplasm. A similar HP1 expression was also experienced
in embryos at the 8-cell and the morula stage. Interestingly, I found that both HP1 and
H3S28P were detected at nucleoli in 1-cell, and from 2-cell embryos to the morula stage,
their signals were found mostly in the nucleoplasm. From that point, I concluded that for
any sites in which HP1 was expressed, H3S28P was also detected. | en_US |
