We next established, using specific primers to each 3’UTR (Figure S7, 8), that although all three 3’UTRs are present in the SON, their relative amounts vary substantially (Figure 5D). 3’UTR-2.1 was the most abundant (~ 90% of total 3’UTR), 3’UTR-2.2 was less abundant (~ 10% of total 3’UTR), while 3’UTR-1.0 was hardly detectable (Figure 5D). Therefore, we determined alcohol regulation of expression of the two most abundant 3’UTRs: UTR-2.1 and -2.2. Alcohol did not affect the expression of 3’UTR-2.2; however it caused a dramatic downregulation of 3’UTR-2.1 (Figure 5E) corresponding temporally to the upregulation of miR-9 expression (Figure 4E, F) and to the downregulation of specific BK mRNA variants (Figure 2).
