Revisiting mitogenome evolution in Medusozoa with eight new mitochondrial genomes

Min Kang Ling; Nicholas Wei Liang Yap; Iffah Binte Iesa; Zhi Ting Yip; Danwei Huang; Zheng Bin Randolph Quek

doi:10.1016/j.isci.2023.108252

Revisiting mitogenome evolution in Medusozoa with eight new mitochondrial genomes

iScience. 2023 Oct 18;26(11):108252. doi: 10.1016/j.isci.2023.108252. eCollection 2023 Nov 17.

Authors

Min Kang Ling¹, Nicholas Wei Liang Yap^{2

3}, Iffah Binte Iesa⁴, Zhi Ting Yip¹, Danwei Huang^{1

2

4}, Zheng Bin Randolph Quek^{1

5}

Affiliations

¹ Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore 117558, Singapore.
² Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, Singapore 119227, Singapore.
³ St. John's Island National Marine Laboratory, c/o Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, Singapore 119227, Singapore.
⁴ Lee Kong Chian Natural History Museum, National University of Singapore, 2 Conservatory Drive, Singapore 117377, Singapore.
⁵ Yale-NUS College, National University of Singapore, Singapore 138527, Singapore.

Abstract

Mitogenomics has improved our understanding of medusozoan phylogeny. However, sequenced medusozoan mitogenomes remain scarce, and Medusozoa phylogeny studies often analyze mitogenomic sequences without incorporating mitogenome rearrangements. To better understand medusozoan evolution, we analyzed Medusozoa mitogenome phylogeny by sequencing and assembling eight mitogenomes from three classes (Cubozoa, Hydrozoa, and Scyphozoa). We reconstructed the mitogenome phylogeny using these mitogenomes and 84 other existing cnidarian mitogenomes to study mitochondrial gene rearrangements. All reconstructed mitogenomes had 13 mitochondrial protein-coding genes and two ribosomal genes typical for Medusozoa. Non-cubozoan mitogenomes were all linear and had typical gene orders, while arrangement of genes in the fragmented Cubozoa (Morbakka sp.) mitogenome differed from other Cubozoa mitogenomes. Gene order comparisons and ancestral state reconstruction suggest minimal rearrangements within medusozoan classes except for Hydrozoa. Our findings support a staurozoan ancestral medusozoan gene order, expand the pool of available medusozoan mitogenomes, and enhance our understanding of medusozoan phylogenetic relationships.

Keywords: genomics; phylogeny.