Abstract
We report the first mitochondrial genomes of two Orthalicoidea land snails from the Atacama Desert of northern Chile,
Bostryx erythrostoma
and
Plectostylus broderipii
. Using Illumina short-read sequencing, we assembled and annotated mitochondrial genomes of 15,525 bp and 14,978 bp, respectively, with strong A+T bias (69.75% in
B. erythrostoma
; 72.08% in
P. broderipii
). Both genomes retain the standard metazoan mitochondrial complement of 37 genes, including 13 protein-coding genes (PCGs), 22 tRNAs, and two rRNAs, with differences in total length mainly due to variation in non-coding regions rather than coding-gene content. Comparative analysis showed that the two species share the same order of the 13 PCGs, whereas differences are concentrated in local tRNA/rRNA rearrangements and intergenic architecture. Both mitogenomes also exhibit negative AT skew and positive GC skew under a standardized orientation. Phylogenetic inference based on a concatenated 13-PCG nucleotide supermatrix resolved both taxa within Orthalicoidea with strong support:
B. erythrostoma
grouped with a congeneric
Bostryx
reference, and this clade clustered with
Rabdotus mooreanus
and
Naesiotus nux
, whereas
P. broderipii
was inferred as sister to this orthalicoid cluster.