1. Aberrant DNA methylation of imprinted H19 gene in human preimplantation embryos 
Shi-Ling Chen, M.D., M.Sc., Xiao-Yun Shi, M.D., M.Sc., Hai-Yan Zheng, M.D., Fang-Rong Wu, M.D., Chen Luo, M.Sc. 
Fertility and Sterility 
Volume 94, Issue 6, Pages e1 (November 2010)
DOI: /j.fertnstert
Copyright © 2010 American Society for Reproductive Medicine Terms and Conditions

2. Figure 1
DNA methylation patterns of H19 DMR were determined by COBRA using the Taq I restriction enzyme. The digested PCR products were separated on 4% agarose gels; gel images were saved as TIFF files. The 230-bp bands represented unmethylated maternal alleles; 100-bp and 130-bp bands represented methylated paternal alleles. The percentage of methylation was calculated as the density ratio of the two methylated bands to the total three bands. (A) Leukocyte controls showed the differential methylation pattern (about half methylated and half unmethylated), whereas oocytes and sperm exhibited the unmethylated pattern and methylated pattern, respectively. (B) Methylation patterns in most embryos were very similar to those of somatic leukocytes, except that embryo no. 7 (another four embryos not shown here) showed a demethylation pattern and embryo no. 22 exhibited a hypomethylation pattern (14% methylation). (C) To determine the source of altered H19 DMR methylation in six embryos, we examined methylation of the six sperm samples that were used to fertilize the corresponding embryos (no. 7, 16, 17, 22, 31, and 32). Normal hypermethylation patterns were confirmed in all six sperm samples.
Fertility and Sterility  , e1DOI: ( /j.fertnstert )
Copyright © 2010 American Society for Reproductive Medicine Terms and Conditions