(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Eukaryota: NE > Opisthokonta: NE > Metazoa: NE > Eumetazoa: NE > Bilateria: NE > Deuterostomia: NE > Chordata: NE > Tunicata: NE > Appendicularia: NE > Oikopleuridae: NE > Oikopleura: NE > Oikopleura dioica: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA MLLLFGVFCLCRLQAFTLEVPVHVKLADGSPIRGKKVKSVNETEIEAYLG IRYAKAPVGEKRFAQPEPVDSWSSQYNATRFGNSCWQTNDDTYGEFKGSA MWNPNTKKDEDCLFLNVWTSGKTQKKAIWIYGGSFNSGTASLEVYDGRVL ASLGDVVVVSLNYRLGPFGFMPRLDDSVSDNAGLLDQRLAMQWVKTNIHK FGGDPDNVTIFGESAGGASVGMHLISPKSWLLFNRAVMQSGSTMSNWASA TEELAISKTLELGRKAGIQSCDISSATDRRRFLASLRQLDAQTLTDSQWV DSADEIFEFSFVPVIGKTGDTLPGDPKELFREGKFKKTDIIFGWNKNEGS WFNTYVLEGFDVNTDSLVSPDSYERNLYKCGLGLDKVGLASVAFEYAPWD NPADKAGYRDALDEIVAHKHVTCPGIELLQNVAKFRDLRAYGYQLDSLIS SNPWPKWMGVMHGYEIEYVFGTILLQDQGFYPMVKFNPEEFVLTKRMIQY WTNFAKTGSPMGNSSSNKKYQLKNLPLWETFDSEFNRYLILDQVSNQTML KSGILPHHRKCEFWTRQIPELKRLTSSISDDMTAWKDDLGRWNSAMNRWE DAFDKFSRGRRNRE
References
Title: DNA interference: DNA-induced gene silencing in the appendicularian Oikopleura dioica Omotezako T, Onuma TA, Nishida H Ref: Proc Biol Sci, 282:, 2015 : PubMed
RNA interference is widely employed as a gene-silencing system in eukaryotes for host defence against invading nucleic acids. In response to invading double-stranded RNA (dsRNA), mRNA is degraded in sequence-specific manner. So far, however, DNA interference (DNAi) has been reported only in plants, ciliates and archaea, and has not been explored in Metazoa. Here, we demonstrate that linear double-stranded DNA promotes both sequence-specific transcription blocking and mRNA degradation in developing embryos of the appendicularian Oikopleura dioica. Introduced polymerase chain reaction (PCR) products or linearized plasmids encoding Brachyury induced tail malformation and mRNA degradation. This malformation was also promoted by DNA fragments of the putative 5'-flanking region and intron without the coding region. PCR products encoding Zic-like1 and acetylcholine esterase also induced loss of sensory organ and muscle acetylcholinesterase activity, respectively. Co-injection of mRNA encoding EGFP and mCherry, and PCR products encoding these fluorescent proteins, induced sequence-specific decrease in the green or red fluorescence, respectively. These results suggest that O. dioica possesses a defence system against exogenous DNA and RNA, and that DNA fragment-induced gene silencing would be mediated through transcription blocking as well as mRNA degradation. This is the first report of DNAi in Metazoa.
Genomes of animals as different as sponges and humans show conservation of global architecture. Here we show that multiple genomic features including transposon diversity, developmental gene repertoire, physical gene order, and intron-exon organization are shattered in the tunicate Oikopleura, belonging to the sister group of vertebrates and retaining chordate morphology. Ancestral architecture of animal genomes can be deeply modified and may therefore be largely nonadaptive. This rapidly evolving animal lineage thus offers unique perspectives on the level of genome plasticity. It also illuminates issues as fundamental as the mechanisms of intron gain.
