Methylation status of IGF1 gene in antler mesenchyme of female, male reindeer and sika deer. A: A schematic represents the distribution of the CpG site in the IGF1 gene and the analyzed sequence represents a 666 base pair fragment (positions −50 ~ +615) in the promoter region of IGF1 gene. B: Electrophoresis of BSP products of IGF1. C: IGF1 methylation levels in antler mesenchyme of female, male reindeer and sika deer. TSS, transcription start sites; vertical line, CpG sites; RF, female reindeer antler mesenchyme; RM, male reindeer antler mesenchyme; SM, male sika deer antler mesenchyme; *0.01<P<0.05, **P<0.01.