Predicting Mouse Oocyte Methylome from Polar Body by Single-cell Whole Genome Bisulfite Sequencing
Refereed conference paper presented and published in conference proceedings


摘要Evaluating oocyte quality in assisted reproductive technology (ART) is essential to ensure a healthy pregnancy. Currently, morphological assessment on oocyte is applied to predict oocyte and embryo development potential. The method is limited and may not provide an accurate assessment of oocyte quality. Human polar body (PB) is the byproduct of an oocyte maturation. The advent of PB karyotyping has served as an indirect genetic analysis of oocytes and provided metrics of embryonic potential. This prompts the idea of oocyte genome interrogation by studying PB genome, and a recent study has shown transcriptome of PB could accurately reflect the transcriptome landscapes of the sibling oocyte. Yet the epigenetic dynamics of PB and oocyte remains elusive. Here we hypothesized that the methylome profile of PB could be representative of oocyte methylome.
To reveal the epigenome information on PB and oocyte, we performed single­cell whole genome bisulfite sequencing (scWBS) on mouse metaphase II (MII) oocytes and the associated PBs. Overall, we detected 1,653,985 CpG sites in the oocyte and 55,941 CpG sites in the PB respectively. The genome­wide methylation level of CpG sites in PB was 73.56%, compared to 54.85% in oocyte. To examine if PB methylome could predict oocyte methylome landscape, all CpG sites covered with more than 3 reads and a window size of 2,000 bp were used to calculate the correlation of methylation level between PB and its sibling oocyte. They showed a moderate Pearson’s correlation coefficient (r=0.5295), which was consistent with published data. We also calculated the correlation of methylation level in promoter region, but to our surprise, the correlation was weak (r=0.209). These results suggested that global methylation level in the mouse PB could not be applied to predict it sibling oocyte methylome. In summary, our preliminary data suggests that the correlation of global methylation level between mouse oocyte and its sibling oocyte is not as high as expected, but this conclusion need to be further confirmed by analyzing more samples.
著者Tin-Lap LEE, Wai-Yee CHAN, Yan QIAN, Cao QIN, Kevin Yuk-Lap YIP, King Lau CHOW, Nelson L.S. TANG, Jinyue LIAO, Alfred Chun Shui LUK, Hoi Ching SUEN, Wing Tung LEE, Ming Peng ZHAO, Grace Wing Shan KONG, Hoi Sze CHUNG, David Yiu leung CHAN, Tak Yeung LEUNG, Tin Chiu LI
會議名稱Experimental Biology 2018
會議地點San Diego
叢書冊次Issue 1 (Suppl)
頁次Abstract No. 3020

上次更新時間 2018-07-12 於 16:50