Genetic and morphological variation analyses of Glandirana rugosa with description of a new species (Anura, Ranidae)

Abstract

Glandirana rugosa is known to include several geographic groups differing in sex chromosomes, and has been proven to be paraphyletic in mitochondrial phylogeny with respect to G. susurra. By analyzing genetic and morphological variation in a large number of individuals of Glandirana, we studied their taxonomic relationships. A mitochondrial DNA phylogeny, with the G. tientaiensis as outgroup, revealed two major lineages containing respectively (1) the East group of G. rugosa, G. susurra, and the Central and Southeast-Kyushu groups of G. rugosa; and (2) G. emeljanovi, and the North and West groups of G. rugosa. In contrast, in a nuclear DNA phylogeny based on SNP data, lineages of (1) G. susurra and East group, and (2) the remaining groups of G. rugosa and G. emeljanovi, were split, indicating a distinct status of the East group among G. rugosa. In adult morphology, there were only minor differences between the East group and the remaining groups of G. rugosa, but in larvae, the East group had significantly more sparse skin glands than the others. The exact type locality of G. rugosa is most probably in western Japan, not including the range of the East group. From these results, we describe the East group as a new species, G. reliquia, distinct from the remaining groups of G. rugosa. The new species with sexually homomorphic chromosomes is thought to represent a basic stock of Japanese Glandirana, which existed far before G. rugosa originated.

Unleashing diversity through flexibility: The evolutionary journey of sex chromosomes in amphibians and reptiles

“…Significant differences in the morphology and sex chromosome composition within a single species can sometimes lead to its classification as a separate species. Recently, the East Japan population distributed in eastern Japan with homomorphic sex chromosomes of G. rugosa was identified as a new species Glandirana reliquia , distinct from the remaining populations of G. rugosa , based on morphological and phylogenetic analyses (Shimada et al, 2022). Further detailed analyses of species exhibiting different characteristics of sex chromosomes between populations will provide insights into not only the evolutionary process of sex chromosomes but also speciation process in these species.…”

“…These results reveal the presence of shared genetic linkages (chromosome 7) between the sex chromosomes in both the ZW and XY populations of G. rugosa . Recent DArTseq analysis using individuals of the West Japan population and the related species G. reliquia (formerly the East Japan population of G. rugosa ) (Shimada et al, 2022) indicated that sex‐linked DNA markers were located on different homologous chromosomes, chromosome 3 in the West Japan population and chromosome 1 in G. reliquia , from the sex chromosomes in the ZW and XY populations (Miura et al, 2022). These results demonstrate that at least two turnovers of sex chromosomes occurred within G. rugosa and the related species G. reliquia .…”

“…Significant differences in the morphology and sex chromosome composition within a single species can sometimes lead to its classification as a separate species. Recently, the East Japan population distributed in eastern Japan with homomorphic sex chromosomes of G. rugosa was identified as a new species Glandirana reliquia, distinct from the remaining populations of G. rugosa, based on morphological and phylogenetic analyses (Shimada et al, 2022).…”