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- Angleby, Helen
(författare)
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Analysis of domestic dog mitochondrial DNA sequence variation for forensic investigations
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The first method for DNA analysis in forensics was presented in 1985. Since then, the introduction of the polymerase chain reaction (PCR) has rendered possible the analysis of small amounts of DNA and automated sequencing and fragment analysis techniques have facilitated the analyses. In most cases short tandemly repeated regions (STRs) of nuclear DNA are analysed in forensic investigations, but all samples cannot be successfully analysed using this method. For samples containing minute amounts of DNA or degraded DNA, such as shed hairs, analysis of mitochondrial DNA (mtDNA) is generally more successful due to the presence of thousands of copies of mtDNA molecules per cell. In Sweden, ~40 % of all households have cats or dogs. With ~9 million humans shedding ~100 scalp hairs per day, and ~1.6 million cats and ~1 million dogs shedding hairs it is not surprising that shed hairs are one of the most common biological evidence found at crime scenes. However, the match probability for domestic dog mtDNA analysis has only been investigated in a few minor studies. Furthermore, although breed –sequence correlations of the noncoding mtDNA control region (CR) have been analysed in a few studies, showing limited correlations, no largescale studies have been performed previously. Thus, there have not been any comprehensive studies of forensic informativity of dog mtDNA. In the two papers presented in this thesis we have tried to lay a foundation for forensic use of analysis of domestic dog mtDNA. In the first paper, CR sequences were analysed and the exclusion capacity was investigated for a number of different populations. This is also the first comprehensive study of the correlation between mtDNA CR type and breed, type, and geographic origin of domestic dogs. Since the exclusion capacity for analysis of domestic dog CR sequences is relatively low, it was investigated in the second paper to what extent the discrimination power is improved by analysis of coding sequence. The exclusion capacity improved considerably when 3,000 base pairs of coding sequences where analysed in addition to CR sequences. This study will hopefully work as a basis for future development of analysis of dog mtDNA for forensic purposes.
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2. |
- Angleby, Helen, et al.
(författare)
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Forensic informativity of domestic dog mtDNA control region sequences
- 2005
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Ingår i: Forensic Science International. - : Elsevier BV. - 0379-0738 .- 1872-6283. ; 154:03-feb, s. 99-110
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Tidskriftsartikel (refereegranskat)abstract
- We have analysed the genetic information to be obtained from analysis of mitochondrial DNA (mtDNA) in domestic dogs studying the exclusion capacity in different populations and the correlation between mtDNA types and breeds or types of dogs. The exclusion capacities for a 573 bp sequence of the mitochondrial control region was between 0.86 and 0.95 for dogs in Sweden, the UK, Germany, Japan and China. The direct correlation between mtDNA type and breed, type of dog, and geographical origin of breed was generally low, but in some cases certain mtDNA types were overrepresented in one breed, and for wider groupings such as morphologically similar breeds, some mtDNA types were in many cases found in a distinct group of breeds, often originating from the same geographic region. This type of information may be used as an indication of the breed and, with some degree of probability, to include or exclude certain breeds from being the source of evidence materials.
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3. |
- Angleby, Helen, et al.
(författare)
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Forensic Informativity of similar to 3000bp of Coding Sequence of Domestic Dog mtDNA
- 2014
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Ingår i: Journal of Forensic Sciences. - : Wiley. - 0022-1198 .- 1556-4029. ; 59:4, s. 898-908
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Tidskriftsartikel (refereegranskat)abstract
- The discriminatory power of the noncoding control region (CR) of domestic dog mitochondrial DNA alone is relatively low. The extent to which the discriminatory power could be increased by analyzing additional highly variable coding regions of the mitochondrial genome (mtGenome) was therefore investigated. Genetic variability across the mtGenome was evaluated by phylogenetic analysis, and the three most variable similar to 1kb coding regions identified. We then sampled 100 Swedish dogs to represent breeds in accordance with their frequency in the Swedish population. A previously published dataset of 59 dog mtGenomes collected in the United States was also analyzed. Inclusion of the three coding regions increased the exclusion capacity considerably for the Swedish sample, from 0.920 for the CR alone to 0.964 for all four regions. The number of mtDNA types among all 159 dogs increased from 41 to 72, the four most frequent CR haplotypes being resolved into 22 different haplotypes.
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4. |
- Ding, Z-L, et al.
(författare)
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Origins of domestic dog in southern East Asia is supported by analysis of Y-chromosome DNA.
- 2011
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Ingår i: Heredity. - : Springer Science and Business Media LLC. - 1365-2540 .- 0018-067X. ; 108:5, s. 507-14
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Tidskriftsartikel (refereegranskat)abstract
- Global mitochondrial DNA (mtDNA) data indicates that the dog originates from domestication of wolf in Asia South of Yangtze River (ASY), with minor genetic contributions from dog-wolf hybridisation elsewhere. Archaeological data and autosomal single nucleotide polymorphism data have instead suggested that dogs originate from Europe and/or South West Asia but, because these datasets lack data from ASY, evidence pointing to ASY may have been overlooked. Analyses of additional markers for global datasets, including ASY, are therefore necessary to test if mtDNA phylogeography reflects the actual dog history and not merely stochastic events or selection. Here, we analyse 14,437 bp of Y-chromosome DNA sequence in 151 dogs sampled worldwide. We found 28 haplotypes distributed in five haplogroups. Two haplogroups were universally shared and included three haplotypes carried by 46% of all dogs, but two other haplogroups were primarily restricted to East Asia. Highest genetic diversity and virtually complete phylogenetic coverage was found within ASY. The 151 dogs were estimated to originate from 13-24 wolf founders, but there was no indication of post-domestication dog-wolf hybridisations. Thus, Y-chromosome and mtDNA data give strikingly similar pictures of dog phylogeography, most importantly that roughly 50% of the gene pools are shared universally but only ASY has nearly the full range of genetic diversity, such that the gene pools in all other regions may derive from ASY. This corroborates that ASY was the principal, and possibly sole region of wolf domestication, that a large number of wolves were domesticated, and that subsequent dog-wolf hybridisation contributed modestly to the dog gene pool.
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5. |
- Natanaelsson, Christian, et al.
(författare)
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Dog Y chromosomal DNA sequence : identification, sequencing and SNP discovery
- 2006
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Ingår i: BMC Genetics. - : Springer Science and Business Media LLC. - 1471-2156. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Background: Population genetic studies of dogs have so far mainly been based on analysis of mitochondrial DNA, describing only the history of female dogs. To get a picture of the male history, as well as a second independent marker, there is a need for studies of biallelic Y-chromosome polymorphisms. However, there are no biallelic polymorphisms reported, and only 3200 bp of non-repetitive dog Y-chromosome sequence deposited in GenBank, necessitating the identification of dog Y chromosome sequence and the search for polymorphisms therein. The genome has been only partially sequenced for one male dog, disallowing mapping of the sequence into specific chromosomes. However, by comparing the male genome sequence to the complete female dog genome sequence, candidate Y-chromosome sequence may be identified by exclusion. Results: The male dog genome sequence was analysed by Blast search against the human genome to identify sequences with a best match to the human Y chromosome and to the female dog genome to identify those absent in the female genome. Candidate sequences were then tested for male specificity by PCR of five male and five female dogs. 32 sequences from the male genome, with a total length of 24 kbp, were identified as male specific, based on a match to the human Y chromosome, absence in the female dog genome and male specific PCR results. 14437 bp were then sequenced for 10 male dogs originating from Europe, Southwest Asia, Siberia, East Asia, Africa and America. Nine haplotypes were found, which were defined by 14 substitutions. The genetic distance between the haplotypes indicates that they originate from at least five wolf haplotypes. There was no obvious trend in the geographic distribution of the haplotypes. Conclusion: We have identified 24159 bp of dog Y-chromosome sequence to be used for population genetic studies. We sequenced 14437 bp in a worldwide collection of dogs, identifying 14 SNPs for future SNP analyses, and giving a first description of the dog Y-chromosome phylogeny.
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6. |
- Nyström, Jesper, et al.
(författare)
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Effect of local prey availability on gyrfalcon diet : DNA analysis on ptarmigan remains at nest sites
- 2006
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Ingår i: Journal of Zoology. - : Wiley. - 0952-8369 .- 1469-7998. ; 269:1, s. 57-64
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate how the diet of gyrfalcon Falco rusticolus in northern Sweden was affected by the relative availability of its two main prey species: rock ptarmigan Lagopus mutus and willow ptarmigan Lagopus lagopus. In order to do so, we needed a method to estimate the gyrfalcon's diet proportions of rock and willow ptarmigan from prey remains that we collected from nest sites in separate breeding territories. We also needed a method to calculate the availability of the two prey species in the same breeding territories that the prey remains originated from. We could then compare the diet proportions with prey availability and investigate if the gyrfalcons utilized the two species strictly in relation to their densities, or if they showed a preference for any of the prey species. Morphometric identification to species level from ptarmigan remains was not possible. Therefore, we developed a PCR-based process of DNA analysis, which could be applied on any ptarmigan bone or bone remains. This method allowed us to establish the ratio of rock and willow ptarmigan in gyrfalcon diets that originated from single gyrfalcon breeding occasions. The relative availability of the two ptarmigan species in gyrfalcon breeding territories was calculated with a GIS model that incorporated observations on ptarmigan habitat preferences. The DNA identification was performed on 176 ptarmigan bones from 13 different breeding occasions occurring in five different territories. The results indicated that the two ptarmigan species comprised at least 93% of the average gyrfalcon diet, and that rock ptarmigan was the most common prey during all 13 breeding occasions. There was a positive relationship between the relative amount of rock ptarmigan in the diet and the proportion of rock ptarmigan habitat in the territories; hence, the gyrfalcons ptarmigan utilization seemed to be density dependent. However, rock ptarmigan was found to be overrepresented in the diet, which may reflect a preference for rock ptarmigan over willow ptarmigan. The conservation implications of these findings in relation to ptarmigan hunting are discussed.
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7. |
- Pang, Jun-Feng, et al.
(författare)
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mtDNA data indicate a single origin for dogs south of Yangtze River, less than 16,300 years ago, from numerous wolves.
- 2009
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Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 1537-1719 .- 0737-4038. ; 26:12, s. 2849-64
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Tidskriftsartikel (refereegranskat)abstract
- There is no generally accepted picture of where, when, and how the domestic dog originated. Previous studies of mitochondrial DNA (mtDNA) have failed to establish the time and precise place of origin because of lack of phylogenetic resolution in the so far studied control region (CR), and inadequate sampling. We therefore analyzed entire mitochondrial genomes for 169 dogs to obtain maximal phylogenetic resolution and the CR for 1,543 dogs across the Old World for a comprehensive picture of geographical diversity. Hereby, a detailed picture of the origins of the dog can for the first time be suggested. We obtained evidence that the dog has a single origin in time and space and an estimation of the time of origin, number of founders, and approximate region, which also gives potential clues about the human culture involved. The analyses showed that dogs universally share a common homogenous gene pool containing 10 major haplogroups. However, the full range of genetic diversity, all 10 haplogroups, was found only in southeastern Asia south of Yangtze River, and diversity decreased following a gradient across Eurasia, through seven haplogroups in Central China and five in North China and Southwest (SW)Asia, down to only four haplogroups in Europe. The mean sequence distance to ancestral haplotypes indicates an origin 5,400-16,300 years ago (ya) from at least 51 female wolf founders. These results indicate that the domestic dog originated in southern China less than 16,300 ya, from several hundred wolves. The place and time coincide approximately with the origin of rice agriculture, suggesting that the dogs may have originated among sedentary hunter-gatherers or early farmers, and the numerous founders indicate that wolf taming was an important culture trait.
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