The SYBR Green RT-PCR assay was performed in LightCycler 96 Real-Time PCR System (Roche, USA) by three-step real-time QPCR ac- cording to the FastStart Universal SYBR Green Master Mix kit (Roche, USA) protocol. The thermal cycling parameters for qRT-PCR were 95 "Cfor 600 s followed by 45 cycles of 95 'C for 10s, 57 "C for 10 s and 70 "C for 10s using the gene specific primers MmSK-F3/R3 (Table S1). The internal housekeeping gene B-actin using primers B-actin-F/R (Table S1) was used as a normalization control (Jiang et al., 2015). All reactions were assayed in three biological replicates with three tech- nical replicates. The relative expression differences of mRNAS in dif- ferent tissues were calculated by 2-AAC method (Schmittgen and Livak, 2008). Standard errors and standard deviations were calculated from replicates and statistical significance was measured through One-Way ANOVA Duncan's multiple rang test at the level of 0.01