@article {795,
	title = {Heterogeneity of the internal transcribed spacer (ITS-2) region within individual deer ticks.},
	journal = {Insect Mol Biol},
	volume = {6},
	year = {1997},
	month = {1997 May},
	pages = {123-9},
	abstract = {To determine whether nuclear rDNA sequences provide a useful means for assessing the structure of populations of Ixodes ticks, we compared variability among copies of an internal transcribed spacer (ITS-2) sequence within individual ticks to the variability between ticks. At least 4\% of the nucleotides comprising this sequence vary among the copies present within individual ticks. ITS-2 diversity in each of two ticks is nearly half as great as that reported between ticks from geographically disparate populations. Because individual ticks retain ancestral polymorphism, ITS-2 variation does not accurately reflect descent relationships among these ticks. Sequencing single copies of PCR-amplified ITS-2 therefore does not permit assessment of the phylogenetic relationships among the I. ricinus-like ticks in eastern North America. We recommend caution in future analyses, and emphasize the importance of procedures designed to ensure that the many paralogous copies of the rDNA cistron have been sufficiently homogenized by concerted evolutionary processes. Such precautionary measures will make certain that phylogenetic trees based on these gene sequences reflect the phyletic relatedness of the biological species.},
	keywords = {Animals, Base Sequence, Deer, DNA, DNA, Ribosomal, Genetic Heterogeneity, Ixodes, Molecular Sequence Data},
	issn = {0962-1075},
	author = {Rich, S M and Rosenthal, B M and Telford, S R and Spielman, A and Hartl, D L and Ayala, F J}
}
@article {797,
	title = {A new Borrelia infecting Lone Star ticks.},
	journal = {Lancet},
	volume = {347},
	year = {1996},
	month = {1996 Jan 6},
	pages = {67-8},
	keywords = {Animals, Base Sequence, Borrelia, Borrelia Infections, Deer, Disease Vectors, DNA Primers, Maryland, Molecular Sequence Data, Ticks},
	issn = {0140-6736},
	author = {Armstrong, P M and Rich, S M and Smith, R D and Hartl, D L and Spielman, A and Telford, S R}
}
@article {798,
	title = {Discriminating between Ixodes ticks by means of mitochondrial DNA sequences.},
	journal = {Mol Phylogenet Evol},
	volume = {4},
	year = {1995},
	month = {1995 Dec},
	pages = {361-5},
	abstract = {Ticks of the genus Ixodes have recently assumed prominence because they frequently serve as vectors of important zoonoses, including Lyme disease and babesiosis. The morphological characteristics that have been used in their identification often are ambiguous and are useful solely at a particular stage of development. Here we report the DNA sequence of the mitochondrially encoded 16S rRNA gene of nine different Ixodes ticks and an outgroup from another genus, Dermacentor. The sequences readily discriminate between these ticks. Samples of I. dammini from the northeastern and upper midwestern United States differ from southeastern I. scapularis at about 2\% of the nucleotides. This difference is about half that separating other members of the I. ricinus group of species, but exceeds typical levels of intraspecific variation. Two major clades exist within the I. ricinus complex. One includes I. cookei, I. hexagonus, and I. angustus. The other includes I. persulcatus, I. pacificus, I. muris, I. ricinus, I. scapularis, and I. dammini. We conclude that mtDNA sequences are useful for unravelling the systematics of these important vectors of human disease.},
	keywords = {Animals, Arachnid Vectors, Base Sequence, Dermacentor, DNA Primers, DNA, Mitochondrial, Genes, Humans, Ixodes, Molecular Sequence Data, Phylogeny, Polymerase Chain Reaction, RNA, Ribosomal, 16S, Species Specificity},
	issn = {1055-7903},
	doi = {10.1006/mpev.1995.1033},
	author = {Caporale, D A and Rich, S M and Spielman, A and Telford, S R and Kocher, T D}
}
@article {799,
	title = {Distribution of the Ixodes ricinus-like ticks of eastern North America.},
	journal = {Proc Natl Acad Sci U S A},
	volume = {92},
	year = {1995},
	month = {1995 Jul 3},
	pages = {6284-8},
	abstract = {We analyzed the geographic distribution of the Ixodes ricinus-like ticks in eastern North America by comparing the mitochondrial 16S rDNA sequences of specimens sampled directly from the field during the 1990s. Two distinct lineages are evident. The southern clade includes ticks from the southeastern and middle-eastern regions of the United States. The range of the northern clade, which appears to have been restricted to the northeastern region until the mid-1900s, now extends throughout the northeastern and middle-eastern regions. These phyletic units correspond to northern and southern taxa that have previously been assigned specific status as Ixodes dammini and Ixodes scapularis, respectively. The expanding range of I. dammini appears to drive the present outbreaks of zoonotic disease in eastern North America that include Lyme disease and human babesiosis.},
	keywords = {Animals, Base Sequence, Demography, DNA Primers, DNA, Mitochondrial, DNA, Ribosomal, Geography, Mitochondria, Molecular Sequence Data, Phylogeny, Polymerase Chain Reaction, Population, RNA, Ribosomal, 16S, Ticks, United States},
	issn = {0027-8424},
	author = {Rich, S M and Caporale, D A and Telford, S R and Kocher, T D and Hartl, D L and Spielman, A}
}
