Identification of small non-coding RNAs from mitochondria and chloroplasts

摘要: Small non-protein-coding RNAs (ncRNAs) have been identified in a wide spectrum of organisms ranging from bacteria to humans. In eukarya, systematic searches for ncRNAs so far restricted the nuclear or cytosolic compartments cells. Whether not small stable non-coding RNA species also exist cell organelles, addition tRNAs ribosomal RNAs, is unknown. We thus generated cDNA libraries size-selected mammalian mitochondrial and plant chloroplast searched ncRNA these two types DNA-containing organelles. total, we 18 novel candidates organellar cellular confirmed expression six them by northern blot analysis RNase A protection assays. Most candidate genes map intergenic regions genomes. As found previously bacteria, presumptive ancestors present-day chloroplasts mitochondria, observed examples antisense that potentially could target organelle-encoded mRNAs. The structural features as well their possible functions are discussed. absence our abundant encoded genomes suggests import into organelles very limited significance does occur at all.