Daphnia galeata is an important plankton in aquatic ecosystems. As a widely distributed species, D. galeata has been found throughout the Holarctic region. Understanding the genetic diversity and evolution of D. galeata requires the accumulation of genetic information from different locations. Even though the mitochondrial genome (mitogenome) sequence of D. galeata has already been reported, little is known about the evolution of its mitochondrial control region. In this study, D. galeata samples were collected from the Han River on the Korean Peninsula and its partial nd2 gene was sequenced for haplotype network analysis. This analysis showed that four clades of D. galeata were present in the Holarctic region. Moreover, the D. galeata examined in this study belonged to clade D and was specific to South Korea. The mitogenome of D. galeata from the Han River showed similar gene content and structure compared to sequences reported from Japan. Furthermore, the structure of control region of the Han River was similar to those of Japanese clones and differed substantially from European clone. Finally, a phylogenetic analysis based on the amino acid sequences of 13 protein-coding genes (PCGs) indicated that D. galeata from the Han River formed a cluster with clones collected from Lakes Kasumigaura, Shirakaba, and Kizaki in Japan. The differences in control region structure and stem and loop structure reflect the different evolutionary directions of the mitogenomes from Asian and European clones. These findings improve our understanding of the mitogenome structure and genetic diversity of D. galeata.
Keywords: Control region; Daphnia galeata; Evolution; Han River; Mitogenome; Phylogeny.
© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.