FIGURE 5.

miR-375 is virtually absent from intestinal contents. A, miR-375 copy number in stomach milk and downstream intestinal contents of D14 375KO offspring (milk, n = 8; intestinal contents, n = 12). The dotted line represents the detection limit of the qPCR. B, miR-375 Northern blot analysis of D14 intestinal contents (40 μg) with adult mammary tissue (14 μg) used as a positive control. miR-200c expression was used as an RNA loading control. C, WT milk from the stomachs of D14 375KO pups was incubated with the intestinal contents of 375KO pups at 37 °C on a shaker, with equal-volume aliquots collected at specific time points (n = 3). Synthetic cel-miR-39 was spiked in as an exogenous control. qPCR absolute quantification was used to determine the percentage of copies remaining relative to the starting material (at time 0). Results represent mean ± S.E.