Experimental evaluation does not reveal a direct effect of microRNA from the callipyge locus on DLK1 expression

BACKGROUND: Polar overdominance at the ovine callipyge (CLPG) locus involves the post-transcriptional trans-inhibition of DLK1 in skeletal muscle of CLPG/CLPG sheep. The abundant maternally expressed microRNAs (miRNAs) mapping to the imprinted DLK1-GTL2 domain are prime candidate mediators of this trans-effect. RESULTS: We have tested the affinity of 121 miRNAs processed from this locus for DLK1 by co-transfecting COS1 cells with a vector expressing the full-length ovine DLK1 with corresponding mimic miRNAs. None of the tested miRNAs was able to down regulate DLK1 to the extent observed in vivo. CONCLUSIONS: This suggests that other factors, with or without these miRNAs, are involved in mediating the observed trans-effect. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-944) contains supplementary material, which is available to authorized users.