Comparative Analysis of Plant Genomes
Recently two phenomena were reported in eukaryotes: (1) transcription of the Head-to-Head (H2H) adjacent genes from the shared promoter; and (2) chimeric mRNAs/proteins produced via alternative transcription termination, splicing and translation of the Tail-to-Head (T2H) genes. We scanned the Arabidopsis and rice genomes for the presence of closely located (at distance of less than 600 and 1000 bp, respectively) H2H and T2H genes. 1631 H2H and 6895 T2H gene pairs in Arabidopsis, and 512 H2H and 1,386 T2H gene pairs in rice were found. Short spacers between H2H genes may serve as shared promoters. Moreover, our studies suggest that some T2H pairs may produce chimeric transcripts. We obtained cDNA support for 100 Arabidopsis and 42 rice T2H pairs to be transcribed into chimeric mRNA(s). Analysis of 155 chimeric transcripts from both species revealed 71 monocistronic, 58 bicistronic and 4 tricistronic mRNAs potentially encoding chimeric or separate proteins.
Shahmuradov, I.A., Abdulazimova, A.U., Solovyev, V.V., Qamar, R., Chohan, S.N. and Aliyev, J.A.