The complete mitochondrial genome of the taimen, Hucho taimen, and its unusual features in the control region

摘要

The whole mitochondrial genome of Hucho taimen was firstly sequenced and characterized. The genome is 16,833 bp in length and contains 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a noncoding control region. Twelve protein-coding genes on the heavy strand showed that the content of A+T was higher than that of G+C, whereas the nd6 protein-coding gene on the light strand displayed an opposite pattern. We described the secondary structure of the origin of light strand (oriL) replication and found that the conserved 5′-GCCGG-3′ sequence motif is variable in H. taimen and some other salmonids. We conclude that the control region is variable in length and represents the high A+T content, compared with other mitochondrial control regions available in Salmonidae and other non-salmonids. Additionally, another interesting feature of H. taimen mitogenome is that a T-type mononucleotide microsatellite and an 82 bp tandem repeat were identified in the control region.