Nuclear microsatellite and mitochondrial DNA analyses reveal the regional genetic structure and phylogeographical history of a sanguivorous land leech, Haemadipsa japonica, in Japan

Abstract

Recent molecular studies have indicated that phylogeographical history of Japanese biota is likely shaped by geohistory along with biological events, such as distribution shifts, isolation, and divergence of populations. However, the genetic structure and phylogeographical history of terrestrial Annelida species, including leech species, are poorly understood. Therefore, we aimed to understand the genetic structure and phylogeographical history across the natural range of Haemadipsa japonica , a sanguivorous land leech species endemic to Japan, by using nine polymorphic nuclear microsatellites (nSSR) and cytochrome oxidase subunit one (COI) sequences of mitochondrial DNA (mtDNA). Analyses using nSSR revealed that H . japonica exhibited a stronger regional genetic differentiation among populations ( G ' ST = 0.77) than other animal species, probably because of the low mobility of land leech. Analyses using mtDNA indicated that H . japonica exhibited two distinct lineages (A and B), which were estimated to have diverged in the middle Pleistocene and probably because of range fragmentation resulting from climatic change and glacial and interglacial cycles. Lineage A was widely distributed across Japan, and lineage B was found in southwestern Japan. Analyses using nSSR revealed that lineage A was roughly divided into two population groups (i.e., northeastern and southwestern Japan); these analyses also revealed a gradual decrease in genetic diversity with increasing latitude in lineage A and a strong genetic drift in populations of northeastern Japan. Combined with the largely unresolved shallow polytomies from the mtDNA phylogeny, these results implied that lineage A may have undergone a rapid northward migration, probably during the Holocene. Then, the regional genetic structure with local unique gene pools may have been formed within each lineage because of the low mobility of this leech species.

Lumping three nominal species into one: taxonomic revision of amphibian parasitic leeches of Torix in Far East Asia (Hirudinea: Glossiphoniidae)

“…1, 2). This boundary is similar to that observed in a haemadipsid leech in Japan that is attributed to the expansion from northern and southern refugia (Morishima and Aizawa 2019).…”

Host–parasite relationships between seabirds and the haemadipsid leechChtonobdella palmyrae(Annelida: Clitellata) inhabiting oceanic islands in the Pacific Ocean

“…1). Therefore, this study provides additional distribution records of this species well beyond its original known range; only trignathous Haemadipsa leeches have previously been recorded in the Far East (Lai et al ., 2011; Seo et al ., 2013; Morishima and Aizawa, 2019).…”

Concordant genetic structures of sika deer and Japanese land leeches suggest that the current range expansion of Haemadipsa japonica is dependent on sika deer migration: A case study from Tochigi Prefecture, Japan

“…Multiplex PCR were performed by using methods described elsewhere (Morishima & Aizawa, 2019). Genotypes were determined by using an ABI 3500 Genetic Analyzer and GeneMapper ver.…”

“…In Tochigi Prefecture, the sika deer distribution ranges from the northwestern to the southwestern regions (Figure 2; Tochigi Prefecture, 2017) and overlaps with the H. japonica distribution range found in both the northern and southern regions (Figure 1). However, a previous study using H. japonica microsatellite markers showed that limited mobility likely resulted in marked genetic differentiation and reduced gene flow between populations (Morishima & Aizawa, 2019). Similar regional genetic differentiation was also found in other leech species in Cambodia (Tessler et al, 2018), suggesting that leeches do not move a lot.…”

“…Individuals at K = 2 in the STRUCTURE clustering result are represented by horizontal lines. The population codes (10-15) correspond to those shown in Morishima and Aizawa (2019). by using mitochondrial DNA (mtDNA) analysis (Table S1; Morishima et al, 2020).…”