title: Heterogeneity of ITS1 sequences in the biting midge Culicoides impunctatus (Goetghebuer) suggests a population in Argyll, Scotland, may be genetically distinct.
abstract: Ribosomal DNA (rDNA) internal transcribed spacer 1 (ITS1) is a useful genomic region for understanding evolutionary and genetic relationships. In the current study, variation in ITS1 from eight Culicoides species was analysed by PCR, DNA restriction analysis, cloning, and sequencing. ITS1 variants were essentially homogenized within a species, as sequences were identical or closely related. However, Culicoides impunctatus ITS1 sequences derived from one (Argyll) of five populations contained considerable genomic diversity. The secondary structure of each ITS1 was computed. The structure aided the production of an accurate alignment and the identification of a large indel. A phylogenetic analysis was performed. Some of the sequences from the diverse Argyll C. impunctatus population were more related to Culicoides imicola, a vector of animal pathogens in the Old World, than they were to the other C. impunctatus sequences. Thus, the rDNA ITS1 regions of individuals in the Argyll C. impunctatus population were not conforming to the general theory of rDNA homogenization through molecular drive.
authors.affiliation: Scottish Crop Research Institute, Invergowrie, Dundee, Scotland, UK.
authors.forename: Allyson
authors.initials: A
authors.lastname: Ritchie
authors.forename: Alison
authors.initials: A
authors.lastname: Blackwell
authors.forename: Gaynor
authors.initials: G
authors.lastname: Malloch
authors.forename: Brian
authors.initials: B
authors.lastname: Fenton
mesh_terms: D000818:Animals; D001483:Base Sequence; D002519:Ceratopogonidae / Q000235:genetics*; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D018740:Genetic Heterogeneity; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D012606:Scotland; D012689:Sequence Homology, Nucleic Acid
chemical_list: D004275:DNA, Ribosomal