Abstract:

Objective To understand whether there are al differences of MECP2 between male and female brains, which may contribute to the gender differences in MECP2 associated diseases, e.g. autism. Methods Genomic DNA of brain tissues from four normal aborted fetuses was obtained by phenol-chloroform extraction. By using MethPrimer online software, the CpG island of MECP2 gene was enriched between -1 000 bp to + 1 200 bp. To detect the level of methylation, bisulfite sequencing method was used (by using the EZ DNA Methylation-goldTM Kit ). For ultrasound fractured genomic DNA, ChIP assay was performed with genomic hydroxymethyl kit (diagenode, hMeDIP Kit). The levels of MECP2 in brain tissues were detected with cDNA that was obtained by FastQuant RT Kit (With gDNase) and were quantitated using SuperReal PreMix Plus (SYBR Green) kits. Results Sample 1, male,weight 106 g, length 17.4 cm;sample 2, female, weight 100 g,length 19.1 cm; sample 3, male, weight 500 g, length 28.3 cm; sample 4, female, weight 510 g, length 31.5 cm. The level of MECP2 in brain of male (sample1=0.0367, sample3=0.0155) was higher than that in female (sample2=0.0177, sample 4=0.0088) during early embryonic stage. The methylation level of the core promoter region of MECP2 in male was significantly lower than that in female per X chromosome, especially in the core promoter region -309 bp to -179 bp. Almost no methylation appeared on MECP2 in brain of male while the hydroxymethylation level was the opposite. Conclusion These results indicated that the gene modifications on MECP2 in male may contribute to its . This may in turn increase the susceptibility of male to MECP2 mutations in disease such as autism and result in sex ratio changes in patient population.