A repeat complex in the mitochondrial control region of Adelie penguins from Antarctica

We have determined the nucleotide sequence of the entire mitochondrial cont rol region (CR) of the Adelie penguin (Pygoscelis adeliae) from Antarctica. Like in most other birds, this CR region is flanked by the gene nad6 and t ransfer (t)RNA trnE(uuc) at the 5' end and the gene rns and trnF(gaa) at th e 3' end. Sequence analysis shows that the Adelie penguin CR contains many elements in common with other CRs including the termination associated sequ ences (TAS), conserved F, E, D, and C boxes, the conserved sequence block ( CSB)-1, as well as the putative light and heavy strand promoters sites (LSP -HSP). We report an extraordinarily long avian control region (1758 bp) whi ch can be attributed to the presence, at the 3' peripheral domain, of five 81-bp repeat sequences, each containing a putative LSP-HSP, followed by 30 tetranucleotide microsatellite repeat sequences consisting of (dC-dA-dA-dA) (30). The microsatellite and the 81-bp repeat reside in an area known to be transcribed in other species.