Adaptive Evolution Coupled with Retrotransposon Exaptation Allowed for the Generation of a Human-Protein-Specific Coding Gene That Promotes Cancer Cell Proliferation and Metastasis in Both Haematological Malignancies and Solid Tumours: The Extraordinary Case of MYEOV Gene

Figure 1

MYEOV alternatively spliced variants. Illustrated on top is the genomic organization of MYEOV locus. Bold, orange line boxes correspond to exonic segments of the genomic sequence. Pentagons overlapping the boxes delineate the location and orientation of the three TEs referred to in the text. (a–f) Six MYEOV alternatively spliced variants encode for either MYEOV-313 or MYEOV-255, according to the NCBI Gene database. Bold, black line boxes for MYEOV exonic content corresponding to each variant. Directional arrows correspond to the functional start signals of MYEOV; red directional arrows are for the start codons demarcating the respective pORF in each variant. The common stop codon location (TGA) is also indicated. Provided below the exonic content, depicted as dark-grey horizontal bars and juxtaposed to the respective pORFs (red horizontal bars), are the uORFs present in each mRNA sequence; long uORFs are annotated in the context of significantly impairing translational efficiency. Numbers in parentheses correspond to consecutive reading frames, starting from the first, second, and third nucleotide of each variant. Importantly, a prerequisite for MYEOV long-ORF to occur is the region demarcated by red vertical lines to be spliced out of the mRNA sequence.