Both and B1 originated from 7SL RNA. has a dimeric form with a very similar left and right arm, whereas B1 has a monomeric form similar to the left arm of the element. The most selected 5'ss and 3'ss within the exonized element in the antisense orientation. The right and left arm are shown by boxes. The numbers within the boxes indicate positions (according to the consensus sequence) in which the prevalent 3'ss and 5'ss are selected, above and below the boxes, respectively. Pictogram depiction of each splice site is shown, the consensus sequence of is marked above the pictogram, and the number of times that the site was selected is shown below it. Similar presentation as in panel a for the prevalent 5'ss and 3'ss selected in B1 and mammalian interspersed repeat (MIR) elements, respectively.
Taken from "Comparative analysis of transposed element insertion within human and mouse genomes reveals 's unique role in shaping the human transcriptome"
Genome Biology 2007;8(6):R127-R127.
Published online 27 Jun 2007