A transgene (Drosophila sex lethal, sxl) insertion 20 kb from Mkrn1-ps1 was shown to cause reduced
life span, reduced bone density, bone deformities, renal polycystic dilation and early opening eyes.
This phenotype was observed when the transgene was inherited paternally (99/108), but only rarely
when inherited maternally (3/96)(Hirotsune
S, et al. 2003).
Although Mkrn1-ps1 was reported to be preferentially paternally expressed (Hirotsune
S, et al. 2003) the expression and imprinting of Mkrn1-ps1 has been firmly refuted (Gray
TA et al, 2006).