The nearly complete mitochondrial genome of the door snail Euphaedusa aculus (Stylommatophora: Clausiliidae) and phylogenetic analysis

Abstract

The family Clausiliidae was proposed as a model for studying the diversity of breeding biology in land snails. This study assembled a nearly complete mitogenome (15,417 bp) for the clausiliid snail Euphaedusa aculus. The mitogenome includes 13 protein-coding genes (PCGs), two ribosomal RNAs, and 22 transfer RNAs, with a gene order consistent with other clausiliids. Most PCGs use ATN start codons and complete stop codons, except for atp6, nad4, and nad5, which start with TTG, and atp6, cox3, and nad3, which have incomplete stop codons. Phylogenetic analyses revealed that E. aculus is closely related to E. planostriata. This mitogenome provides a valuable molecular resource for future evolutionary research on land snails.

Keywords: Clausiliidae; Mitogenome; door snail; phylogenetic relationships.

Figure 1.

The shell morphology of Euphaedusa aculus. Scale bar = 1 mm. This is an original image by the authors.

Figure 2.

Mitogenome map of Euphaedusa aculus. Arrows indicate the orientation of gene transcription. The protein-coding genes (PCGs) are shown as blue arrows, rRNA genes as purple arrows, and tRNA genes as pink color arrows. The GC content is plotted using a black sliding window as the deviation from the average GC content of the entire sequence. The GC-skew is plotted using a colored sliding window (green and orchid color) as the deviation from the average GC skew of the whole sequence. Abbreviations of gene names are: atp6 and atp8 for ATP synthase subunits 6 and 8, cox1-3 for cytochrome oxidase subunits 1-3, cytb for cytochrome b, nad1-6 and nad4L for NADH dehydrogenase subunits 1-6 and 4 L, rrnL, and rrnS for large and small rRNA subunits. tRNA genes are indicated with one-letter corresponding amino acids; the two tRNA genes for leucine and serine have different anticodons.

Figure 3.

Phylogenetic trees generated using maximum likelihood and Bayesian interference based on the 13 protein-coding genes and two rRNA genes. ML bootstrap and BI posterior probability values were shown on the nodes. The mitogenome sequences used including Deroceras reticulatum KY765589 (Ahn et al. 2017); Ryssota otaheitana NC044784 (Guzmán et al. 2021); Punctum randolphii MT361346; Albinaria caerulea NC001761; Euphaedusa planostriata MW118059 (Zhang et al. 2021); Euphaedusa aculus PP485172 (this study); Micrarionta opuntia NC060988; Gastrocopta cristata KC185403 (Groenenberg et al. 2017); Vertigo pusilla NC026045 (Schultz et al. 2018); Virpazaria ripkeni MT431577; Achatinella mustelina KU525108, Achatinella sowerbyana KX356680 (Price et al. 2016); Partulina redfieldi MG925057 (Price et al. 2018); Melampus sincaporensis NC086654.