Chromosomes and C-banding of Opisthorchis viverrini.

Chromosome of Opisthorchis viverrini was observed by air-drying and C-banding techniques. The chromosome number was 2n=12 and n=6 consisting of one large-sized metacentric, one medium-sized metacentric, one small-sized metacentric, one small-sized submetacentric or subtelecentric, one small-sized subtelocentric or acrocentric and one small-sized acrocentric. The relative lengths of the chromosomes were 32.02 +/- 2.52, 23.28 +/- 1.98, 15.24 +/- 3.40, 13.39 +/- 3.11, 10.18 +/- 1.56 and 5.82 +/- 0.59% respectively. After C-banding treatment, two of the small-sized chromosomes showed a remarkable constitutive heterochromatin.