The complete mitochondrial genome of the gray garden slug Deroceras reticulatum (Gastropoda: Pulmonata: Stylommatophora)

Authors: AHN, SEUNG-JOON - Oregon State University; Martin, Ruth; RAO, SUJAYA - Oregon State University; Choi, Man-Yeon

Submitted to: Mitochondrial DNA Part B
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/2017
Publication Date: 4/27/2017
Citation: Ahn, S., Martin, R.C., Rao, S., Choi, M.Y. 2017. The complete mitochondrial genome of the gray garden slug Deroceras reticulatum (Gastropoda: Pulmonata: Stylommatophora). Mitochondrial DNA Part B. 2(1):255-256. doi: 10.1080/23802359.2017.1318677.

Interpretive Summary: The gray garden slug, Deroceras reticulatum, is the most destructive and omnivorous pest on a variety of crops including seed production, field crops, row crops, Christmas tree farms, and horticultural nurseries. The cost of bait applications, direct loss of plants, and the cost of replanting is estimated to cost the seed industry > $50 million in Oregon. In established grass seed fields, slug bait applications are estimated at ~$7 million annually, with an additional $38 million in losses from crop damage in Oregon. Those economic impacts are increasing every year. The most commonly used control method relies on chemical pesticides that have environmental risks associated with this control method including chemical residue, effect on non-target arthropods, and human health risks. In addition, there is the risk that slug populations in the field will develop resistance. Therefore, it is essential to develop appropriate management strategies which focus on biologically-based environmentally friendly alternatives. Most of studies on the slug mainly focused on its ecology, biology, pest status, and control. However, virtually nothing is known about genetic information of the species. Therefore, DNA sequences would be provide essential data to facilitate a better understanding of slug physiology and to develop biological controls for the slug. In this study, scientists from USDA-ARS and Oregon State University, at Corvallis, OR determined the complete mitochondrial genome of the slug. The complete mitochondrial genome provides valuable molecular data for taxonomical identification and further evolutionary studies of terrestrial slugs. Our results possibly offer a critical molecular identification tool for mixed slug species in the field.

Technical Abstract: The complete circular mitochondrial genome of D. reticulatum is 14,048 bp in length, consisting of 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, and 2 ribosomal RNA (rRNA) genes (GenBank accession number: KY765589). The overall base composition was 31.0 % A, 12.2 % C, 17.7 % G and 39.1 % T, indicating a very high AT content (70.1 %). The start codon ATG was used in five PCGs (COX2, ATP8, ATP6, ND3, and ND4), ATA was used in four PCGs (ND6, ND5, ND1, and ND4L), and TTG was used in three PCGs (COX1, CYTB and ND2). Ten PCGs ended with the TAA stop codon, whereas the other three PCGs (CYTB, ATP6 and ND2) used TAG as stop codon. It is notable that the C-terminal sequence of COX1 had approximately an additional 50 aa when compared to other molluscan orthologues. The 22 predicted tRNA genes were spread over the whole mitochondrial genome and varied in length from 53 to 65 bp. The length of the two rRNA genes were 565 bp for the small rRNA (s-rRNA) and 871 bp for the large rRNA (l-rRNA). Comparative genome analysis revealed that the gene order and orientation of the D. reticulatum mitochondrial genome are similar to most other Pulmonata mitochondrial genomes.