The mitochondrial genome of Conus textile, coxI–coxII intergenic sequences and Conoidean evolution

Abstract

The cone snails belong to the superfamily Conoidea, comprising ∼10,000 venomous marine gastropods. We determined the complete mitochondrial DNA sequence of Conus textile. The gene order is identical in Conus textile, Lophiotoma cerithiformis (another Conoidean gastropod), and the neogastropod Ilyanassa obsoleta, (not in the superfamily Conoidea). However, the intergenic interval between the coxI/coxII genes, was much longer in C. textile (165 bp) than in any other previously analyzed gastropod.We used the intergenic region to evaluate evolutionary patterns. In most neogastropods and three conidean families the intergenic interval is small (<30 nucleotides). Within Conus, the variation is from 130-170 bp, and each different clade within Conus has a narrower size distribution. In Conasprella, a subgenus traditionally assigned to Conus, the intergenic regions vary between 200-500 bp, suggesting that the species in Conasprella are not congeneric with Conus. The intergenic region was used for phylogenetic analysis of a group of fish-hunting Conus, despite the short length resolution was better than using standard markers. Thus, the coxI/coxII intergenic region can be used both to define evolutionary relationships between species in a clade, and to understand broad evolutionary patterns across the large superfamily Conoidea.

The relationships of the enigmatic neogastropodLoxotaphrus(Cancellariidae)

“…The dataset used for DNA analysis was mostly derived after Simison et al (2006), Bandyopadhyay et al (2007), Modica et al (2009) and , and included 12S and 16S rDNA sequences of 21 additional neogastropod species belonging in 12 families. EMBL accession numbers of the relevant sequences are the following: FM999072Á75, FM99980Á88, FM999103Á106, FM999111Á116, FM999119Á127, FN391982, FN392228, FN392229, DQ284754 and DQ238598.…”

Molecular systematics of the marine gastropod families Trochidae and Calliostomatidae (Mollusca: Superfamily Trochoidea)

“…Carinastele kristelleae (Marshall, 1988 Oliverio and Mariottini (2001;12SI) and Bandyopadhyay et al (2008;12S(-)). Alternative primers (Koufopanou et al, 1999) were sometimes used to amplify 16S for problematic taxa.…”

Conservation and variation in mitochondrial genomes of gastropods Oncomelania hupensis and Tricula hortensis, intermediate host snails of Schistosoma in China

“…This variation may be considered as extremely high if at intra-species level, even though it is lower than that between genera comparisons, 15.8% and 17.4% at levels of genome and protein-coding genes, respectively for comparison between O. hupensis hupensis and T. hortensoni, and 16% and 17.5% between O. hupensis robertsoni and T. hortensis, and even lower than other comparisons (26-30%) for species in different family or order (Bandyopadhyay et al, 2006(Bandyopadhyay et al, , 2008Simison et al, 2006). In consideration of the difference in morphology and distribution (for details see Liu et al, 1981 andDavis et al, 1995), and in mitochondrial genomes as revealed in the present study, the ribbed-shelled O. hupensis hupensis and the smooth-shelled O. hupensis robertsoni may be considered as separate species, rather than sub-species.…”