(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 > Ascidiacea: NE > Enterogona: NE > Phlebobranchia: NE > Cionidae: NE > Ciona: NE > Ciona intestinalis: 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 LFQGIAGIRSFATTAKMESKSPYKGTSERGLSKEIAIPVPWGILAGKTFG DSTKPAVLCLHGWLDNCNSFDKLIPLLPKDKFYVCVDLPGHGLSSHISLG MFYTLFFYVATVERIVNHFKWKKFSFLSHSLGANISGMYSGTYPDKVDKL IIIDVIGVFPLDGKLAVENLRSSIESYLKYEDKLSSAAPRYTYEKAKERL LVANKSLDSHSADILLERGTTRHEDGLYTYRRDLRHNYRNPVFATPEVAM HLLRNITASTQHIMASKGRTQTSVAARSENVSRLFDCFTSVKKREYVVVE GDHHLHMVNAEEVAKQISPFLNEDIPILTTSVETSK
References
Title: Complete mtDNA of Ciona intestinalis reveals extensive gene rearrangement and the presence of an atp8 and an extra trnM gene in ascidians Gissi C, Iannelli F, Pesole G Ref: Journal of Molecular Evolution, 58:376, 2004 : PubMed
The complete mitochondrial genome (mtDNA) of the model organism Ciona intestinalis (Urochordata, Ascidiacea) has been amplified by long-PCR using specific primers designed on putative mitochondrial transcripts identified from publicly available mitochondrial-like expressed sequence tags. The C. intestinalis mtDNA encodes 39 genes: 2 rRNAs, 13 subunits of the respiratory complexes, including ATPase subunit 8 ( atp8), and 24 tRNAs, including 2 tRNA-Met with anticodons 5'-UAU-3'and 5'-CAU-3', respectively. All genes are transcribed from the same strand. This gene content seems to be a common feature of ascidian mtDNAs, as we have verified the presence of a previously undetected atp8 and of two trnM genes in the two other sequenced ascidian mtDNAs. Extensive gene rearrangement has been found in C. intestinalis with respect not only to the common Vertebrata/Cephalochordata/Hemichordata gene organization but also to other ascidian mtDNAs, including the cogeneric Ciona savignyi. Other features such as the absence of long noncoding regions, the shortness of rRNA genes, the low GC content (21.4%), and the absence of asymmetric base distribution between the two strands suggest that this genome is more similar to those of some protostomes than to deuterostomes.
The first chordates appear in the fossil record at the time of the Cambrian explosion, nearly 550 million years ago. The modern ascidian tadpole represents a plausible approximation to these ancestral chordates. To illuminate the origins of chordate and vertebrates, we generated a draft of the protein-coding portion of the genome of the most studied ascidian, Ciona intestinalis. The Ciona genome contains approximately 16,000 protein-coding genes, similar to the number in other invertebrates, but only half that found in vertebrates. Vertebrate gene families are typically found in simplified form in Ciona, suggesting that ascidians contain the basic ancestral complement of genes involved in cell signaling and development. The ascidian genome has also acquired a number of lineage-specific innovations, including a group of genes engaged in cellulose metabolism that are related to those in bacteria and fungi.
