EN
Some of the organellar genes contain introns.Most of genes possesing introns in higher plants contain single introns. Introns found in chloroplast genes can be classified into three groups based on their structures. The largest group includes introns which can be folded into a secondary structure similar to the postulated structure of group II introns in fungal mitochondrial genes.The tobacco, rice and liverwort chloroplast rps 12 is divided into three exons and requires both cis and trans splicing in order to produce the mature mRNA.The genes coding for NADH dehydrogenase subunit I,II,V in mitochondria of some higher plants are split into a few exons which are located in distant genome regions. Maturation of the mRNAs requires both trans and cis splicing reactions.Trans splicing is belived to involve interaction between group II intron pieces.RNA editing appears to be a regulatory mechanism altering the pool of transtable mRNAs.