The mitochondrial genome of the land snail Cernuella virgata (Da Costa, 1778): the first complete sequence in the family Hygromiidae (Pulmonata, Stylommatophora)

Hong-Mu Ai,Pei Wang,Hong-Li Ding,Jun-Hong Lin,Weichuan Zhou

doi:10.3897/zookeys.589.7637

Abstract

The land snail Cernuella virgata (da Costa, 1778) is widely considered as a pest to be quarantined in most countries. In this study, the complete mitochondrial genome of Cernuella virgata is published. The mitochondrial genome has a length of 14,147 bp a DNA base composition of 29.07% A, 36.88% T, 15.59% C and 18.46% G, encoding 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes and two ribosomal RNA (rRNA) genes. The complete nucleotide composition was biased toward adenine and thymine, A+T accounting for 69.80%. Nine PCGs and 14 tRNA genes are encoded on the J strand, and the other four PCGs and eight tRNA genes are encoded on the N strand. The genome also includes 16 intergenic spacers. All PCGs start strictly with ATN, and have conventional stop codons (TAA and TAG). All tRNAs fold into the classic cloverleaf structure, except tRNAArg, tRNASer(UCN), tRNASer(AGN) and tRNAPro. The first three lack the dihydrouridine arm while the last lacks the TψC arm. There are 502 bp long noncoding regions and 418bp long gene overlaps in the whole mitochondrial genome, accounting for 3.54% and 2.95% of the total length respectively. Phylogenetic analyses based on the sequences of the protein coding genes revealed a sister group relationship between the Hygromiidae and the Helicidae.

Highlights

The land snail Cernuella virgata, known as the Mediterranean white snail or Common white snail, is endemic to the Mediterranean and western Europe, and has been introduced to America, Australia and Morocco (Barker 2004)
Twenty-four genes were encoded on the majority coding strand (J strand) while 13 genes were encoded on the minority coding strand (N strand) (tRNAGln, tRNALeu(UUR), tRNAAsn, tRNAArg, tRNAGlu, tRNAMet, tRNASer(UCN), tRNAThr, ATP6, ATP8, ND3, COIII and SrRNA) (Table 3)
In the study of mt genome of C. cicatricosa, GTG is the start codon of the COII gene, and COI and ND6 genes of C. aspersum start with TTG (Gaitán-Espitia et al 2013; Wang et al 2014)

Summary

Introduction

The land snail Cernuella virgata (da Costa, 1778), known as the Mediterranean white snail or Common white snail, is endemic to the Mediterranean and western Europe, and has been introduced to America, Australia and Morocco (Barker 2004). The snail is omnivorous, feeding on detritus and plant matter, such as bark, stems and leaves of various green plants. Does it destroy agricultural crops, such as beans, cereal, various fruits and vegetables, it can spread zoonotic food-borne parasitic diseases. One ship carrying barley from Australia was refused entry and berthing by Chile because of the presence of this snail causing huge economic losses (USDA 2008). It is one of the more important quarantine terrestrial mollusks in America. Owing to its great harm, the snail was listed in “The People’s Republic of China entry plant quarantine pest list” by the government in 2012 to prevent its introduction (MOA and AQSIQ 2012)

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Conclusion