Fig 2 Mixed Tails (IMAGE) Institute for Basic Science Caption Researchers at the Institute for Basic Science found mixed tails, not limited to a repetition of A's, in the rear end of human mRNA. The non-A nucleotide, frequently guanosine (G), is found in the last or next to last position of the tail. This study explained the role of the mixed tails in shielding mRNA tail from rapid shortening. Credit IBS Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.