OBJECTIVE: To investigate the distribution patterns of H3K4me3 and H3K27me3 in human oocytes and preimplantation embryos. DESIGN: Experimental study. SETTING: University reproductive medical center. PATIENT(S): Patients undergoing IVF cycles. INTERVENTION(S): Oocytes and embryos were collected from patients undergoing IVF cycles. MAIN OUTCOME MEASURE(S): The distribution patterns of H3K4me3 and H3K27me3 in oocytes and embryos were analyzed by indirect immunofluorescent staining and scanning confocal microscopy. RESULT(S): H3K4me3 and H3K27me3 signals were detectable at each stage of oocyte and embryonic development. However, only one of the pronuclei showed signal for H3K27me3 in each of the zygotes, whereas H3K4me3 staining was always uniform in all zygotes. The level of H3K4me3 decreased steadily from germinal vesicle to metaphase II stage, obviously increased from zygote stage to four-cell stage, and reached the lowest at eight-cell stage. A sharp increase was then observed at blastocyst stage. The level of H3K27me3 slightly changed from germinal vesicle stage to zygote stage, then decreased steadily and reached the lowest at eight-cell stage, followed by a significant increase at blastocyst stage. CONCLUSION(S): The levels of H3K4me3 and H3K27me3 show dynamic changes during human oocyte maturation and preimplantation embryonic development. Asymmetric distribution of H3K27me3 exists in human zygote pronuclei, whereas H3K4me3 is always uniform in all of the pronuclei.
OBJECTIVE: To investigate the distribution patterns of H3K4me3 and H3K27me3 in human oocytes and preimplantation embryos. DESIGN: Experimental study. SETTING: University reproductive medical center. PATIENT(S): Patients undergoing IVF cycles. INTERVENTION(S): Oocytes and embryos were collected from patients undergoing IVF cycles. MAIN OUTCOME MEASURE(S): The distribution patterns of H3K4me3 and H3K27me3 in oocytes and embryos were analyzed by indirect immunofluorescent staining and scanning confocal microscopy. RESULT(S): H3K4me3 and H3K27me3 signals were detectable at each stage of oocyte and embryonic development. However, only one of the pronuclei showed signal for H3K27me3 in each of the zygotes, whereas H3K4me3 staining was always uniform in all zygotes. The level of H3K4me3 decreased steadily from germinal vesicle to metaphase II stage, obviously increased from zygote stage to four-cell stage, and reached the lowest at eight-cell stage. A sharp increase was then observed at blastocyst stage. The level of H3K27me3 slightly changed from germinal vesicle stage to zygote stage, then decreased steadily and reached the lowest at eight-cell stage, followed by a significant increase at blastocyst stage. CONCLUSION(S): The levels of H3K4me3 and H3K27me3 show dynamic changes during human oocyte maturation and preimplantation embryonic development. Asymmetric distribution of H3K27me3 exists in human zygote pronuclei, whereas H3K4me3 is always uniform in all of the pronuclei.
Authors: Christine van de Werken; Godfried W van der Heijden; Cindy Eleveld; Miriam Teeuwssen; Mareike Albert; Willy M Baarends; Joop S E Laven; Antoine H F M Peters; Esther B Baart Journal: Nat Commun Date: 2014-12-18 Impact factor: 14.919