Conservation in the first internal transcribed spacer region (ITS1) in Hematodinium species infecting crustacean hosts found in the UK and Newfoundland

• Published in: Diseases of aquatic organisms 2007-05, Vol.75 (3), p.251-258
• Main Authors: SMALL, H. J, SHIELDS, J. D, MOSS, J. A, REECE, K. S
• Format: Article
• Language: English
• Subjects: Animals; Base Sequence; Biological and medical sciences; Cancer pagurus; Chionoecetes opilio; Conserved Sequence; Crustacea; Decapoda (Crustacea) - parasitology; Dinoflagellida - genetics; Dinoflagellida - pathogenicity; DNA Primers - chemistry; DNA, Ribosomal - chemistry; DNA, Ribosomal Spacer - chemistry; Fundamental and applied biological sciences. Psychology; Hematodinium; Invertebrates; Marine; Molecular Sequence Data; Nephrops norvegicus; Newfoundland and Labrador; Pagurus; Pagurus bernhardus; Pathology; Polymerase Chain Reaction; RNA, Ribosomal, 18S - genetics; RNA, Ribosomal, 5.8S - genetics; Sequence Alignment; Sequence Homology, Nucleic Acid; United Kingdom
• ISSN: 0177-5103; 1616-1580
• DOI: 10.3354/dao075251

Parasitic dinoflagellates in the genus Hematodinium infect a number of decapod crustaceans in waters off the UK, including the Norway lobster Nephrops norvegicus and the edible crab Cancer pagurus. This study investigated sequence variability in the first internal transcribed spacer (ITS1) region of the ribosomal RNA complex of Hematodinium spp. infecting N. norvegicus, C. pagurus, and Pagurus bernhardus from 4 locations in the UK and from the Hematodinium sp. infecting Chionoecetes opilio from the province of Newfoundland and Labrador, Canada. Phylogenetic analysis of the Hematodinium ITS1 sequences from N. norvegicus, C. pagurus, P. bernhardus and C. opilio suggest that these crustaceans are infected with the same species of Hematodinium. Length variability of the ITS1 region was observed (324 to 345 bp) and attributed to 4 variable microsatellite regions (CATG)n' (GCC)nTCCGC(TG)n' (TA)n' and (GAA)n(GGA)n within the sequenced ITS1 fragment. The observed variation may be due to co-infection of the host crustacean with several different strains of Hematodinium or differences among copies of ITS1 region within the genome of a single parasite cell. The Hematodinium ITS1 sequence from N. norvegicus, C. pagurus, P. bernhardus and C. opilio isolates was sufficiently conserved in primer binding regions targeted by previous molecular diagnostic assays; therefore, we suggest that this assay could be used to screen for Hematodinium infections in these crustacean hosts.