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ABSTRACT: Two groups ofParagonimus westermani (Tematoda: Platyhelminthes) exist in nature: diploids and triploids. Generally, these two groups live allopatrically, but in Kuandian, Liaoning Province, in the Republic of China, they live sympatrically. In our Chinese experiment onParagonimus we used metacercariae ofP. westermani, which we collected in Kuandian, Xigutai, and performed a cytological analysis. The results were as follows: (1) theP. westermani in Xigutai lived sympatrically as diploids and triploids; (2) all of the small metacercariae were diploids; (3) the large metacercariae were in large proportion triploids; (4) we found one tetraploid specimen in both the medium and the large metacercariae — this was the first time tetraploid lung flukes were discovered; (5) the somatic chromosomes of the tetraploids were different in numbers (4n=44), but we could not find any difference in the karyotype of haploid sets and that of the diploids and the triploids; (6) unlike the triploids, during their meiosis the tetraploids produced a chromosome pairing, and we found a tendency of the large chromosomes to become quadrivalent; and (7) also unlike the triploids, a great number of spermatids were found in the tetraploid testes. Because of these findings, we can consider tetraploids to be autotetraploids, and these are probably produced by the fertilization of diploids and triploids. We also think that the gametes of tetraploids have a fertilization capability.
Parasitology Research 06/1995; 81(7):627-630. · 2.15 Impact Factor
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[show abstract]
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ABSTRACT: Two groups of Paragonimus westermani (Tematoda: Platyhelminthes) exist in nature: diploids and triploids. Generally, these two groups live allopatrically, but in Kuandian, Liaoning Province, in the Republic of China, they live sympatrically. In our Chinese experiment on Paragonimus we used metacercariae of P. westermani, which we collected in Kuandian, Xigutai, and performed a cytological analysis. The results were as follows: (1) the P. westermani in Xigutai lived sympatrically as diploids and triploids; (2) all of the small metacercariae were diploids; (3) the large metacercariae were in large proportion triploids; (4) we found one tetraploid specimen in both the medium and the large metacercariae--this was the first time tetraploid lung flukes were discovered; (5) the somatic chromosomes of the tetraploids were different in numbers (4n = 44), but we could not find any difference in the karyotype of haploid sets and that of the diploids and the triploids; (6) unlike the triploids, during their meiosis the tetraploids produced a chromosome pairing, and we found a tendency of the large chromosomes to become quadrivalent; and (7) also unlike the triploids, a great number of spermatids were found in the tetraploid testes. Because of these findings, we can consider tetraploids to be autotetraploids, and these are probably produced by the fertilization of diploids and triploids. We also think that the gametes of tetraploids have a fertilization capability.
Parasitology Research 02/1995; 81(7):627-30. · 2.15 Impact Factor
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ABSTRACT: A total of 18 enzymes (encoded by 20 loci) from Paragonimus heterotremus collected at a local area in Saraburi, Thailand, were electrophoretically compared with those from the three Japanese species P. ohirai, P. miyazaki and P. westermani using horizontal starch-gel electrophoresis. Relative genetic distances between these species were quantified. The Thai P. heterotremus was found to be most closely related to P. miyazaki and rather distantly related to P. westermani. On the other hand, among the three Japanese species, the closest relationship was observed between P. miyazaki and P. ohirai.
Parasitology Research 02/1992; 78(6):463-8. · 2.15 Impact Factor
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Parasitology Research 02/1992; 78(6):537-8. · 2.15 Impact Factor
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ABSTRACT: The newly excysted metacercariae of P. heterotremus were examined by scanning electron microscopy (SEM). Large dome-shaped papillae, small ones with a pit, and small ones with a smooth surface were observed around the suckers. The number of the small dome-shaped papillae with a pit was about 30 around the oral sucker and that of the small ones with a smooth surface varied from 9 to 13 around the ventral sucker. The present report is the first record of excysted metacercariae of P. heterotremus examined by SEM.
The Southeast Asian journal of tropical medicine and public health 04/1990; 21(1):109-13. · 0.60 Impact Factor
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ABSTRACT: During the period from September 1985 to March 1988, the freshwater snails, Semisulcospira libertina, were collected from 4 mountain rivers in Ayama County of Mie Prefecture, which is known as a heavily infected locality with Paragonimus westermani (Kerbert, 1878) Braun, 1899, and were examined for cercariae and rediae of this lung fluke. Of 3,000 snails studied, 80 (2.67%) harbored Paragonimus larvae. The infected snails were found at 3 sites in the Nishitani (A), Nenobi(B), and Higashitani (C) rivers. The infection rate of Paragonimus cercariae at these sites varied from 0.13 to 6.08%. The highest incidence (6.08%) of cercarial infection occurred at site A (Nishitani river), where the prevalence and intensity of infection with P. westermani metacercariae were considerably greater in the 2nd intermediate host crabs. No Paragonimus was observed in 776 snails collected at site D (Taki river), where the incidence and degree of metacercarial infection in crabs were quite small. There was a positive correlation between the infection incidence of P. westermani and the size of S. libertina; the percentage of infected snails increased in larger size classes, reaching 24.14% at a shell length of over 40 mm. In the 80 positive snails there were 51 mixed infections with P. westermani and 1 or 2 other species of trematode larvae. Of these, 43 were double infections and 8 triple. The morphological features of P. westermani cercaria and redia are described.
Nippon juigaku zasshi. The Japanese journal of veterinary science 05/1989; 51(2):315-26.
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Nippon juigaku zasshi. The Japanese journal of veterinary science 03/1988; 50(1):169-74.
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ABSTRACT: We produced monoclonal antibodies against the adult antigen of Paragonimus westermani to investigate the expression of the stage-specific antigen of adult flukes. Two hybridoma cell lines, A1-2 and A4-1, were established. A1-2 reacted specifically only with the adult antigen in an enzyme-linked immunosorbent assay (ELISA), whereas A4-1 reacted with both adult and larval antigens. By immunoblotting analysis, A1-2 was found to react with four bands with molecular weights of 35,000, 17,000, 15,500, and 12,500 in the adult antigen but with none in the larval antigen. A4-1 was found to bind to the band of 27,000 daltons in the adult antigen as well as those of 28,000 and 26,000 daltons in the larval antigen. By immunohistochemical methods, a positive reaction was observed only in the parenchymal tissues of the adult flukes with A1-2. A4-1 reacted with the substance that located on the gut epithelium and in the luminal contents of both the adult and larval flukes. These results indicate that the adult P. westermani possesses an antigen or antigenic determinant specific to the adult stage, as well as that common to both the larval and adult stages.
Parasitology Research 02/1988; 75(2):144-7. · 2.15 Impact Factor
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ABSTRACT: We produced monoclonal antibodies against the adult antigen ofParagonimus westermani to investigate the expression of the stage-specific antigen of adult flukes. Two hybridoma cell lines, A1-2 and A4-1, were established. A1-2 reacted specifically only with the adult antigen in an enzyme-linked immunosorbent assay (ELISA), whereas A4-1 reacted with both adult and larval antigens. By immunoblotting analysis, A1-2 was found to react with four bands with molecular weights of 35000, 17000, 15500, and 12500 in the adult antigen but with none in the larval antigen. A4-1 was found to bind to the band of 27000 daltons in the adult antigen as well as those of 28000 and 26000 daltons in the larval antigen. By immunohistochemical methods, a positive reaction was observed only in the parenchymal tissues of the adult flukes with A1-2. A 4-1 reacted with the substance that located on the gut epithelium and in the luminal contents of both the adult and larval flukes. These results indicate that the adultP. westermani possesses an antigen or antigenic determinant specific to the adult stage, as well as that common to both the larval and adult stages.
Parasitology Research 01/1988; 75(2):144-147. · 2.15 Impact Factor
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ABSTRACT: Applicability of the adult Paragonimus westermani antigen for detection of anti-immature P. westermani antibodies in experimentally infected rats, a paratenic host of this lung fluke, was examined. The serum antibodies of the cats and rats infected with P. westermani metacercariae were detected by enzyme-linked immunosorbent assay (ELISA) with the adult-fluke antigen. The ELISA titers of serum samples of the rats infected with only immature flukes were as high as those of the cats infected with adult flukes. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and the immunoblotting technique showed that a major protein band of 27,000 daltons was recognized in the sera of the infected cats and rats. Immunoperoxidase staining applied on the sectioned flukes provided evidence showing that the antigenic substance was located on the surface of the gut epithelium and in the luminal contents in both adult and immature flukes. The adult-fluke antigen containing the 27,000-dalton substance is applicable as a standard antigen for diagnosis of paragonimiasis westermani in not only definitive hosts but also in paratenic hosts.
Journal of Parasitology 05/1987; 73(2):363-7. · 1.40 Impact Factor
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Nippon juigaku zasshi. The Japanese journal of veterinary science 01/1986; 47(6):889-93.
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Nippon juigaku zasshi. The Japanese journal of veterinary science 09/1985; 47(4):617-25.
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Nippon juigaku zasshi. The Japanese journal of veterinary science 07/1984; 46(3):345-56.
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Nippon juigaku zasshi. The Japanese journal of veterinary science 05/1983; 45(2):227-36.
