Comparison of seven complete mitochondrial genomes from Lamprologus and Neolamprologus (Chordata, Teleostei, Perciformes) and the phylogenetic implications for Cichlidae.

In this study, mitochondrial genomes (mitogenomes) of seven cichlid species ( Lamprologuskungweensis , L.meleagris , L.ornatipinnis , Neolamprologusbrevis , N.caudopunctatus , N.leleupi , and N.similis ) are characterized for the first time. The newly sequenced mitogenomes contained 37 typical genes [13 protein-coding genes (PCGs), two ribosomal RNA genes (rRNAs) and 22 transfer RNA genes (tRNAs)]. The mitogenomes were 16,562 ~ 16,587 bp in length with an A + T composition of 52.1~58.8%. The cichlid mitogenomes had a comparable nucleotide composition, A + T content was higher than the G + C content. The AT-skews of most mitogenomes were inconspicuously positive and the GC-skews were negative, indicating higher occurrences of C than G. Most PCGs started with the conventional start codon, ATN. There was no essential difference in the codon usage patterns of these seven species. Using Ka/Ks, we found the fastest-evolving gene were atp8 . But the results of p-distance indicated that the fastest-evolving gene was nad6. Phylogenetic analysis revealed that L.meleagris did not cluster with Lamprologus species, but with species from the genus Neolamprologus . The novel information obtained about these mitogenomes will contribute to elucidating the complex relationships among cichlid species.