Pulmonate slug evolution is reflected in the de novo genome of Arion vulgaris Moquin-Tandon, 1855

Abstract

Stylommatophoran pulmonate land slugs and snails successfully completed the water-to-land transition from an aquatic ancestor and flourished on land. Of the 30,000 estimated species, very few genomes have so far been published. Here, we assembled and characterized a chromosome-level genome of the “Spanish” slug, Arion vulgaris Moquin-Tandon, 1855, a notorious pest land slug in Europe. Using this reference genome, we conclude that a whole-genome duplication event occurred approximately 93–109 Mya at the base of Stylommatophora and might have promoted land invasion and adaptive radiation. Comparative genomic analyses reveal that genes related to the development of kidney, blood vessels, muscle, and nervous systems had expanded in the last common ancestor of land pulmonates, likely an evolutionary response to the terrestrial challenges of gravity and water loss. Analyses of A. vulgaris gene families and positively selected genes show the slug has evolved a stronger ability to counteract the greater threats of external damage, radiation, and water loss lacking a protective shell. Furthermore, a recent burst of long interspersed elements in the genome of A. vulgaris might affect gene regulation and contribute to rapid phenotype changes in A. vulgaris, which might be conducive to its rapid adaptation and invasiveness.

De novo genome assembly and transcriptome sequencing in foot and mantle tissues of Megaustenia siamensis reveals components of adhesive substances

“…1 B). The genome assembly size of the semislug M. siamensis is notably larger than that of other terrestrial snails and slugs (approximately 1.8 Gb for Lissachatina fulica , 1.5 Gb for Arion vulgaris , and 1.2 Gb for Candidula unifasciata) 10 – 12 . The GC content of M. siamensis is 38.24%, closely resembling that of A. vulgaris (38.46%).…”

“…Studies have examined its protein components, glycosylation, ion content, and mechanical properties 2 , 4 , and advancements in genomic and transcriptomic data enable the reconstruction of snail mucus biosynthetic pathways 9 . However, most studies into the genomic structure and differential gene expression of terrestrial gastropods have focused predominantly on snails and slugs 10 – 12 , neglecting semislugs entirely.…”

Pushed waves, trailing edges, and extreme events: Eco‐evolutionary dynamics of a geographic range shift in the owl limpet, Lottia gigantea

“…We also generated stairway plots displaying the changes in N e over time per each of the four groupings within the Moments analysis, using the unsupervised approach of StairwayPlot 2 (Liu & Fu, 2020). For both Moments and StairwayPlot analyses, we used a generation time of 2 years and a mutation rate of 1.6 × 10–9 (Chen et al., 2022). To further explore population recombination history and effective population sizes, we generated measures of LD decay from plink, and r 2 values were plotted with the following custom script: https://github.com/speciationgenomics/scripts/blob/master/ld_decay_calc.py.…”

Evolutionary Dynamics of Lineage-Specific Class-A GPCR Subsets Reveal Widespread Chemosensory Roles and Adaptations in Lophotrochozoa

“…A thorough examination of the available literature (table S1) indicates that WGD events are highly sporadic across Lophotrochozoa. In Gastropoda, WGDs occurred at key points: (i) at the common ancestor of Stylommatophora, and (ii) within specific Neogastropoda families or potentially at their common ancestor (73)(74)(75)(76)(77). In Bivalvia, such events are noted in families like Ostreidae and Mytilidae (77-79) and uniquely at the base of Decapodiformes within Cephalopoda (77).…”