tspan8, gpa33 and cr/20β-hsd copy number variation. Normalized relative genomic quantity by qPCR is presented for males (blue) and females (purple) for analysis of copy number variation. A and B represent crosses involving different dams. Deviation bars represent standard errors. Asterisks represent the level of significance for sex-specific expression differences: *p ≤ 0.05; **p ≤ 0.01 and ***p < 0.001.