The relationship between apoptosis, chromatin configuration, histone modification and competence of oocytes: A study using the mouse ovary-holding stress model.
The epigenetic factors causing competence differences between SN (surrounded nucleolus) and NSN (non-surrounded nucleolus) oocytes, the significance for the increased histone acetylation and methylation in SN oocytes, and whether chromatin configuration or histone modification determines oocyte competence, are unclear. This study has addressed these issues by using the ovary-holding (OH) stress models where oocyte SN configuration was uncoupled from histone modifications and developmental potential. Prepubertal mouse ovaries containing high percentages of NSN oocytes were preserved at 37 or 39 °C for 1 or 2 h before examination for oocyte chromatin configuration, developmental competence, histone modification and apoptosis. Whereas 1-h OH at 37 °C caused a moderate apoptosis with increased oocyte competence, improved histone modification and a normal NSN-to-SN transition, harsher OH conditions induced a severe apoptosis with decreased oocyte competence, impaired histone modification and a pseudo (premature) NSN-to-SN transition. Observations on Fas/FasL expression and using the gld (generalized lymphoproliferative disorder) mice harboring FasL mutations indicated that OH triggered oocyte apoptosis with activation of the Fas signaling. It was concluded that OH stress caused oocyte apoptosis with activation of the Fas/FasL system and that oocyte competence was more closely correlated with histone modification than with chromatin configuration.
College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City 271018, P. R. China.
Juan
J
Lin
College of Life Science, Northeast Agricultural University, Harbin, 150030, P. R. China.
Fei
F
Chen
College of Life Science, Northeast Agricultural University, Harbin, 150030, P. R. China.
Ming-Ju
MJ
Sun
College of Life Science, Northeast Agricultural University, Harbin, 150030, P. R. China.
Jiang
J
Zhu
College of Life Science, Northeast Agricultural University, Harbin, 150030, P. R. China.
You-Wei
YW
Li
College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City 271018, P. R. China.
Liu-Zhu
LZ
Pan
College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City 271018, P. R. China.
Jie
J
Zhang
College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City 271018, P. R. China.|College of Life Science, Northeast Agricultural University, Harbin, 150030, P. R. China.
Jing-He
JH
Tan
D000107:Acetylation; D000818:Animals; D017209:Apoptosis; D002466:Cell Nucleolus / Q000378:metabolism; D002843:Chromatin / Q000737:chemistry*; D054885:Cumulus Cells / Q000166:cytology; D053222:Fas Ligand Protein / Q000737:chemistry; D005260:Female; D006107:Granulosa Cells / Q000166:cytology; D006570:Heterochromatin / Q000737:chemistry; D042421:Histone Code; D006657:Histones / Q000737:chemistry*; D008232:Lymphoproliferative Disorders / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009865:Oocytes / Q000166:cytology*; D009866:Oogenesis / Q000502:physiology; D006080:Ovarian Follicle / Q000378:metabolism; D010053:Ovary / Q000502:physiology*; D000072417:Protein Domains; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000737:chemistry; D015398:Signal Transduction; D013696:Temperature
D002843:Chromatin; D053222:Fas Ligand Protein; D006570:Heterochromatin; D006657:Histones; D011994:Recombinant Proteins