The complete mitochondrial genome of the hagfish Myxine glutinosa: Unique features of the control region

The complete sequence of the mitochondrial DNA of the hagfish Myxine glutin osa has been determined. The hagfish mtDNA (18,909 bp) is the longest verte brate mtDNA determined so far. The gene arrangement conforms to the consens us vertebrate type and differs from that of lampreys. The exceptionally lon g (3628-bp) control region of the hagfish contains the typical conserved el ements found in other vertebrate mtDNAs but is characterized by a large num ber of putative hairpins, which can potentially fold into a highly compact secondary structure that appears to be unique to hagfish. The comparison of the mtDNAs of two M. glutinosa specimens, excluding the control region, sh ows a 0.6% divergence at the nucleotide level as a sample of intraspecies p olymorphism.