Figure 4.

(A) Sequence comparison of the rpL3 alternatively spliced intron among mammals. Nucleotide sequences of human, bovine and mouse intron 3 (hInt3, bInt3 and mInt3, respectively) are aligned. Conserved residues are shaded in gray; the region retained by alternative splicing is underlined. The numbers on right of sequences indicate the nucleotide positions of the human rpL3 gene according to the corresponding GenBank sequences. Accession nos of sequences (NCBI/GenBank): AJ238851 and NT_039621 for bovine and mouse genes, respectively; for the human gene, refer to the legend to Figure 1 (the arrowhead indicates the alternative splice site). (B) Comparative analysis of rpL3 introns among mammals. The numbers indicate the percent nucleotide identity of human sequences compared to the mouse and bovine genes. For intron 3, the nucleotide identity of the portions retained and excised by alternative splicing is indicated.