How many miRNA will be down regulated after knocking down Dicer in mouse - (Mar/20/2010 )
We knocked down Dicer in mouse germ cells and found only a small set of microRNA down regulated. Is it reasonable? How about genes? We also got a small set of genes up regulated.
By the way, we detected all mouse microRNA expression by microarray.
How long after siRNA transfection did you check for miRNAs? I think that they can be quite stable.
Keep in mind that dicer may be redundant in its function, although dicer knockout in mice is lethal.
Can competition and saturation explain what you see?
Also, please note you may not be able to "efficiently" knock down Dicer by "shRNA" since shRNA needs Dicer to get processed.