Functional expression study of igf2 antisense transcript in mouse.

Insulin-like growth factor antisense gene (Igf2as) expression was investigated in different mouse tissues during development, in differentiating C2C12 cells and in a ΔDMR1-U2 knockout mouse model. The expression levels of Igf2as were high in fetal and newborn liver and muscle tissues compared to adults. The Igf2as gene was also expressed in placenta and in brain.

The Igf2as transcript is exported into cytoplasm and associated with polysomes.

Murine insulin-like growth factor 2 antisense (Igf2as) transcripts originate from the opposite strand of the same Igf2 locus as the Igf2 sense mRNA. The Igf2, insulin 2 (Ins2), and H19 genes form a cluster of imprinted genes on chromosome 7. Loss of imprinting of IGF2 in humans is associated with Beckwith-Wiedemann syndrome and Silver-Russell syndrome, as well as with Wilm's tumor and colorectal cancer.