DAO 46:217-222 (2001)  -  doi:10.3354/dao046217

Sequence analysis of the ribosomal internal transcribed spacer DNA of the crayfish parasite Psorospermium haeckeli

Eakaphun Bangyeekhun1, Heikki J. Ryynänen1,2, Paula Henttonen2, Jay V. Huner3, Lage Cerenius1, Kenneth Söderhäll1,*

1Department of Comparative Physiology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18A, 752 36 Uppsala, Sweden
2Institute of Applied Biotechnology, Kuopio University, PO Box 1627, 70211 Kuopio, Finland
3Crawfish Research Center, University of Southwestern Louisiana, Lafayette, Louisiana 70504-4650, USA
*Corresponding author. E-mail:

ABSTRACT: Two morphotypes of the crayfish parasite Psorospermium haeckeli were isolated from 2 crayfish species of different geographical origin. The oval-shaped sporocysts were obtained from the epidermal and connective tissue beneath the carapace of the noble crayfish Astacus astacus from Sweden and Finland. Elongated spores were isolated from the abdominal muscle tissue of the red swamp crayfish Procambarus clarkii from USA. To compare genetic divergence of 2 morphotypes of the parasite, the ribosomal internal transcribed spacer (ITS) DNA (ITS 1 and ITS 2) and the 5.8S rRNA gene were cloned and sequenced. The analysed region is variable in length, with the ribosomal ITS sequence of the European morphotype longer than the North American one. Sequence diversity is found mainly in ITS 1 and ITS 2 regions, and there is 66% and 58% similarity between the 2 morphotypes, respectively. Thus, analysis of the ribosomal ITS DNA suggests that P. haeckeli forms obtained from Europe and North America are genetically diverse, which supports the previously reported morphological characteristics.


KEY WORDS: Psorospermium haeckeli · Astacus astacus · Procambarus clarkii · Crayfish · Parasite · Ribosomal RNA · Internal transcribed spacer


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Cite this article as: Bangyeekhun E, Ryynänen HJ, Henttonen P, Huner JV, Cerenius L, Söderhäll K (2001) Sequence analysis of the ribosomal internal transcribed spacer DNA of the crayfish parasite Psorospermium haeckeli. Dis Aquat Org 46:217-222. https://doi.org/10.3354/dao046217

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