The complete mitochondrial genomes of two vent squat lobsters, Munidopsis lauensis and M.verrilli: Novel gene arrangements and phylogenetic implications.

Shao'E Sun,Zhongli Sha,Yanrong Wang

doi:10.1002/ece3.5542

Abstract

Hydrothermal vents are considered as one of the most extremely harsh environments on the Earth. In this study, the complete mitogenomes of hydrothermal vent squat lobsters, Munidopsis lauensis and M. verrilli, were determined through Illumina sequencing and compared with other available mitogenomes of anomurans. The mitogenomes of M. lauensis (17,483 bp) and M. verrilli (17,636 bp) are the largest among all Anomura mitogenomes, while the A+T contents of M. lauensis (62.40%) and M. verrilli (63.99%) are the lowest. The mitogenomes of M. lauensis and M. verrilli display novel gene arrangements, which might be the result of three tandem duplication–random loss (tdrl) events from the ancestral pancrustacean pattern. The mitochondrial gene orders of M. lauensis and M. verrilli shared the most similarities with S. crosnieri. The phylogenetic analyses based on both gene order data and nucleotide sequences (PCGs and rRNAs) revealed that the two species were closely related to Shinkaia crosnieri. Positive selection analysis revealed that eighteen residues in seven genes (atp8, Cytb, nad3, nad4, nad4l, nad5, and nad6) of the hydrothermal vent anomurans were positively selected sites.

Highlights

The Anomura MacLeay, 1838 is a highly diverse infraorder of deca‐ pod, including seven superfamilies, 17 families, and approximately 2,500 species (Ahyong, Schnabel, & Maas, 2009; Bracken‐Grissom, Cannon, Cabezas, Feldmann, & Crandall, 2013; Schnabel, Ahyong, & Maas, 2011)
In order to identify contigs of mitochondrial origin, we aligned the putative mitochondrial DNA (mtDNA) of M. lauensis and M. verrilli with the published complete mitochondrial genomes of the Galatheoidea, Kiwa tyleri (KY423514), Munida gregaria (KU521508), Neopetrolisthes maculatus (KC107816), Shinkaia crosnieri (EU420129), and Petrolisthes haswelli (LN624374) with the aid of “Alignment” tool implemented in the CLC Genomic Workbench with the default setting
There was a highly possibility that the longest contig in each sample was the mitogenome of M. lauensis or M. ver‐ rilli, which was assembled from multiple overlapping reads

Summary

Introduction

The Anomura MacLeay, 1838 is a highly diverse infraorder of deca‐ pod, including seven superfamilies, 17 families, and approximately 2,500 species (Ahyong, Schnabel, & Maas, 2009; Bracken‐Grissom, Cannon, Cabezas, Feldmann, & Crandall, 2013; Schnabel, Ahyong, & Maas, 2011). Deep‐sea hydrothermal vent is one of the chemosynthetically driven ecosystems and characterized with high temperature (up to 390°C), low oxygen levels, enriched hy‐ drogen sulfide (H2S), methane (CH4), and heavy metals, such as iron, zinc, and copper (Little & Vrijenhoek, 2003). Decapod crustaceans, such as alvinocaridid shrimps, bythograeid crabs, and galatheid squat lobsters, are dominant fauna in the hydrothermal vents, rep‐ resenting approximately 10% of all taxa reported from these vents (Little & Vrijenhoek, 2003; Martin & Haney, 2005; Yang et al, 2013). A powerful system is needed to examine the adaptation evolution at the molecular level (e.g., mitochondrial genome)

Methods

Results

Conclusion