miRNA stands for micro RNA and mRNA stands for messenger RNA. Here’s a look at the differences between the two.

miRNA

• Is only present in eukaryotic cells but absent in prokaryotic cells
• Functions as an epigenetic repressor of protein translation
• Is a short nucleotide sequence measuring approximately 20-22 nt
• Is smaller than most forms of RNA
• Capable of controlling gene expression
• Is believed to have evolved from CRISPR genes of bacteria

mRNA

• Is present in both eukaryotic and prokaryotic cells
• Functions as a messenger, carrying messages from DNA in the nucleus to ribosomes on the ER, where it is first translated into a corresponding sequence of amino acids and then synthesized into protein
• Is directly transcribed from DNA
• Capable of detecting the amino acid sequence of a peptide
• Evolves on mutation of its parent gene