ABSTRACT
MicroRNAs (miRNA) are short RNA molecules regulating the expression of specific mRNAs. We investigated the expression pattern and potential targets of mouse miR-140 and found that miR-140 is specifically expressed in cartilage tissues of mouse embryos during both long and flat bone development. MiR-140 expression was detected in the limbs of E11.5 embryos in the primorida of future bones both in the fore and hindlimb and across autopod, zeugopod and stylopod. All digits of E14.5 fore- and hindlimbs showed accumulation of miR-140, except the first digit of the hindlimb. MiR-140 expression was also detected in the cartilagenous base of E17.5 skulls and in the sternum, the proximal rib heads and the developing vertebral column of E15.5 embryos. A potential target of miR-140, histone deacetylase 4, was validated experimentally and the possible role of miR-140 in long bone development is discussed.
Subject(s)
Cartilage/embryology , Gene Expression Regulation, Developmental/physiology , Gene Expression Regulation, Enzymologic/physiology , Histone Deacetylases/biosynthesis , MicroRNAs/biosynthesis , Osteogenesis/physiology , Animals , Cartilage/cytology , Hindlimb/cytology , Hindlimb/embryology , In Situ Hybridization , Mice , Skull Base/cytology , Skull Base/embryologyABSTRACT
MicroRNAs (miRNAs) are small regulatory molecules suppressing mRNA activity in metazoans. Here we describe two new miRNAs cloned from brain tissue of mouse embryos. These miRNAs are expressed mainly during embryogenesis and specifically in the central nervous system. We also established the expression patterns of three recently identified miRNAs that were found in our short RNA library. All of them were expressed in the brain and spinal chord but while miR-410 and miR-431 were central nervous system specific, miR-500 was also expressed in limb buds. In addition, the expression of miR-500 in limb buds showed very strong asymmetry in favour of the left hand side.
