Investigation of Laser Supported Detonation Structure Using Half Self-emission Half Shadowgraph Method

報告番号: ; 学位授与年月日: 2012-03-22 ; 学位の種別: 修士 ; 学位の種類: 修士(科学) ; 学位記番号: 修創域第4180号 ; 研究科・専攻: 新領域創成科学研究科基盤科学研究系先端エネルギー工学専

Expression levels and DNA methylation profiles of the growth gene SHOX in cartilage tissues and chondrocytes

Abstract All attempts to identify male-specific growth genes in humans have failed. This study aimed to clarify why men are taller than women. Microarray-based transcriptome analysis of the cartilage tissues of four adults and chondrocytes of 12 children showed that the median expression levels of SHOX, a growth gene in the pseudoautosomal region (PAR), were higher in male samples than in female samples. Male-dominant SHOX expression was confirmed by quantitative RT-PCR for 36 cartilage samples. Reduced representation bisulfite sequencing of four cartilage samples revealed sex-biased DNA methylation in the SHOX-flanking regions, and pyrosequencing of 22 cartilage samples confirmed male-dominant DNA methylation at the CpG sites in the SHOX upstream region and exon 6a. DNA methylation indexes of these regions were positively correlated with SHOX expression levels. These results, together with prior findings that PAR genes often exhibit male-dominant expression, imply that the relatively low SHOX expression in female cartilage tissues reflects the partial spread of X chromosome inactivation into PAR. Altogether, this study provides the first indication that sex differences in height are ascribed, at least in part, to the sex-dependent epigenetic regulation of SHOX. Our findings deserve further validation