C-banding analysis of six species of lung flukes,Paragonimus spp. (Trematoda: Platyhelminthes), from Japan and Korea

Abstract

We examined C-banded karyotypes of six species of lung flukes from Japan and Korea; diploid and triploid Paragonimus westermani, P. miyazakii, P. ohirai, P. iloktsuenensis and P. sadoensis, with special reference to their karyotypic diversification. C-band analysis between the diploid and the triploid westermani revealed that two of three homologues of the triploid resembled those of the diploid in C-band pattern, while the remaining chromosome showed a different pattern from any species examined here. This karyological evidence indicates that the triploid is allotriploid probably induced by interspecific hybridization between the diploid westermani and an unknown species; we, therefore, suggest that the triploid westermani is an independent species and synonymous with P. pulmonalis (Miyazaki 1978). As the morphologically similar three species, ohirai, iloktsuenensis and sadoensis, had the same C-band polymorphism in chromosome No. 4, these species are classified as the local races of P. ohirai. Paragonimus miyazakii has one common C-band (5q) with the diploid westermani, but other bands (1q, 4q, 6q, 7p and 7q) are different. From these observations, the six species examined are phylogenetically divided into three groups: (1) westermani group containing diploid and triploid (= pulmonalis) species, (2) miyazakii and (3) ohirai including two geographic races, iloktsuenensis and sadoensis.

Phylogenetic relationship of ribosomal ITS2 and mitochondrial COI among diploid and triploid Paragonimus westermani isolates

“…Using the conventional Giemsa staining technique, Hirai et al (1985) observed that the triploid was an allotriploid, probably induced by interspecific hybridization between the diploid P. westermani and an unknown species. In addition, they suggested that the triploid P. westermani was an independent species and synonymous with P. pulmonalis (Miyazaki, 1978).…”

“…Only diploid forms have been found to date in southeastern countries (Malaysia, Philippines and Thailand). However, both diploid and triploid forms of P. westermani have been found in Korea (Terasaki, 1980;Hirai et al, 1985). Many studies have been focused on the origins of triploids and their relationships with diploid P. westermani, and chromosomal studies have proven to be important for evaluating competing theories with respect to the origins of triploids.…”

“…Many studies have been focused on the origins of triploids and their relationships with diploid P. westermani, and chromosomal studies have proven to be important for evaluating competing theories with respect to the origins of triploids. Sakaguchi and Tada (1980) and Hirai et al (1985) analyzed the karyotype of P. westermani in Japan and Korea and reported that all 11 sets of three homologous chromosomes from triploids were identical. Terasaki et al (1995) observed that each chromosome set in diploid and triploid cells from mixoploid lung flukes was identical to that found in diploid and triploid flukes.…”

Biodiversity of flukes

“…Karyotypes of two P. westermani strains revealed the existence of diploid flukes (2n = 22) in the strain of small-sized stages and triploids (3n = 33) in the other. This triploid strain was then identified as Paragonimus pulmonalis, a species which is become a synonym (Hirai et al, 1985). Diversity can enhance different forms of pathogenicity.…”

Chromosome studies ofIchthyocotylurus platycephalus(Creplin, 1825) Odening 1969 with description of triploid variant and comparative karyology of the genusIchthyocotylurus

“…Paragonimus westermani -3 n = 33 (Sakaguchi & Tada, 1976;Hirai et al, 1985), Allocreadium fasciatusi-3 n = 21 (Ramanjaneyulu & Madhavi, 1984), Apatemon minor -3 n = 30 (Petkeviciute, 1992), Diplostomum sp. -3 n = 30 (Staneviciute, 1994), Schistosoma mansoni -2 n = 24 (Hirai & LoVerde, 1989).…”