>Ak1|NM_021515|3'UTR
   1 CTGGATCCCTTGGCCAGCTCCCAGCCCGCCCCACCCTTGCTCCCTGACCCCAGGCAGCCTGGCTCAAGCCCAGCACCTCC
  81 ACCCTGCCGGGCTGTGCACAGACACAGGAAGCCATGTTATCCTGTCCCATGGACACTAAAGAAATTGCCAAGGAGGGTTA
 161 GGATTGCTCCTTTCCTTTGCTTCCAGTTATGGTGATTCATGCTGCCACAGCCGGAGGCCCCAGCGTGGCCGGCCCATTCT
 241 TCCCTGTGCCTCAGCCCAGCTGTCTTGTCTCCCTCTGGCTCTGCTGGGATCCTAGGCCCTTCCTTAGCCAGGCTGTGTCA
 321 AAGCCTAGGGGTCCCTGGGTTGGCAGGCTGCTCTGGGGGGTCTGGTGTTCACCCTGTTTCTCATAGCCTCGTTGTGTGGC
 401 TTTGGCCCTAAGCCATTGTCTCTCTGGAGTGAGTTTTCTTTTTTTCTTTCTTTCTTTTTCTTTTTTTTCTTTCTCTGTTT
 481 CTTTCTTTTTTTTTTTTTTTAAGACAGCATCTCGTGTGACTTAAGCTGGCCTCAACCCTGTTATGTAACTAAGGGCAACC
 561 TTAATCCTTCTGCCTCCACTTGTCTTCCTGTGTGCTGAGATTACAGGTGTGTGTGTGGACCTCCACCACTCCTGGTTTTG
 641 GGGGCACTGGGAATCAAGCCCATGGCCCTGTATACGAGGCCAGCACGCTACAGAGTGAGCTGCATCCCGGGCTGGGCAGG
 721 TTTTCTGTGCCTGACTGGGGTCTGGCATGGGCAAAGGGCAAAGGGCCATGGGCTCACCAGCTGGGGCCACGTGGTCACTG
 801 GGTGCCAAGGAGCTGTGCAATGGGCATACAGCTAGGTGGGAAGCTGGGGTCAGGGGTGGCCTTCCTGAAGAAGGCTCCCT
 881 TGGTATAGACCTGCCAGGCCTTGCCATCCTTTGGCTGGTTTTAAAGCTTGTCCTGTCACGCTATGTCCCAACCCTTATCC
 961 TCGGCGTTAAGACAAGAGCATGCAGATTAAGGAGTGTGAGCTGCCATAGACAAGGATGTGGGATCAAGGACCAGGCCTGG
1041 GACCCGGAGAGGACACCCAGGGATGCCAAGAAGAGCTGGCATCTCTCTTCTGCTCTTTATTCTTTGGTCTCATTACACAG
1121 GAAGCCTCTGTTGGTACTCACTTGTCCTGGGGCCCCGTCTCCATCCCTAGTGACTTCCCCTGTAAGCCCAGATAGCCTGT
1201 AAGCCAGCAGCCATGGCTGTCCCAGGGACACCTGCCCCTGGGGGTGACGGTGCTCACTCCTTTCTGTTTACTACCAGTGG
1281 GGCCACCTTTCCTTCTGCATTGCCTATTTAAGCTGTCCTTTAAAATAAATAAATGTATTTCAGTTATAAAAAAAAAAAAA
1361 AAAAAAAAAA

ID	Duplex structure	Position	Score	MFE
1	miRNA 3' gaaGGUCAGCUCCUACAAAUGu 5' :|| || ||||||| Target 5' tgcTCACTCCTTTCTGTTTACt 3'	1251 - 1272	143.00	-6.60
2	miRNA 3' gaAGGUCAGCUCCU---ACAAAUGu 5' || || | | |: ||| ||| Target 5' aaTCAAGCCCATGGCCCTGTATACg 3'	652 - 676	120.00	-6.60
3	miRNA 3' gaAGGUCAGCUC---CUACAAAUGu 5' ||::| |:| |:|||| || Target 5' gcTCTGG-GGGGTCTGGTGTTCACc 3'	350 - 373	119.00	-9.40

- Gastroenterology, 2009

BACKGROUND & AIMS: The function of microRNA (miRNA) in liver development is unknown. To address this issue, we characterized miRNA expression in the embryonic mouse liver, performed functional miRNA analysis in zebrafish larvae, and identified novel hepatic miRNA targets. METHODS: Hepatic RNA isolated from mice at embryonic days 15.5, 18.5, and postnatal day 2 was hybridized to a mouse miRNA microarray. The microarray results were confirmed by Northern blot hybridization and quantitative reverse-transcription polymerase chain reaction. The spatial distribution of selected miRNAs was determined by in situ hybridization. Functional analysis of miR-30a was performed in zebrafish using antisense-mediated miRNA knockdown. Targets of miR-30a were identified by microarray analysis of gene expression following knockdown in cultured cells. RESULTS: A set of 38 differentially expressed fetal hepatic miRNAs was identified. Several of these miRNAs were found to exhibit distinct temporal and spatial patterns of expression in hepatocytes, cholangiocytes, and nonepithelial cells within the liver. Two (miR-30a and miR-30c) are the first examples of ductal plate and bile duct-specific hepatic miRNAs. Knockdown of miR-30a in the zebrafish larva results in defective biliary morphogenesis. Several newly identified targets of miR-30a are known regulators of liver development and function. CONCLUSIONS: We have identified miRNAs whose spatial and temporal patterns of expression are suggestive of functional roles in hepatic development and/or function. One of these, the biliary miRNA miR-30a, is required for biliary development in zebrafish. This is the first demonstration of a functional role for miRNA in hepatic organogenesis.