| 1. |
- Lippold, Sebastian, et al.
(författare)
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Discovery of lost diversity of paternal horse lineages using ancient DNA
- 2011
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 2, s. 450-
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Tidskriftsartikel (refereegranskat)abstract
- Modern domestic horses display abundant genetic diversity within female-inherited mitochondrial DNA, but practically no sequence diversity on the male-inherited Y chromosome. Several hypotheses have been proposed to explain this discrepancy, but can only be tested through knowledge of the diversity in both the ancestral (pre-domestication) maternal and paternal lineages. As wild horses are practically extinct, ancient DNA studies offer the only means to assess this ancestral diversity. Here we show considerable ancestral diversity in ancient male horses by sequencing 4 kb of Y chromosomal DNA from eight ancient wild horses and one 2,800-year-old domesticated horse. Both ancient and modern domestic horses form a separate branch from the ancient wild horses, with the Przewalski horse at its base. Our methodology establishes the feasibility of re-sequencing long ancient nuclear DNA fragments and demonstrates the power of ancient Y chromosome DNA sequence data to provide insights into the evolutionary history of populations.
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| 2. |
- Olofsson, Ludwig, et al.
(författare)
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Norway spruce (Picea abies (L.) H. Karst.) selection forests at Siljansfors in Central Sweden
- 2023
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Ingår i: Trees, Forests and People. - 2666-7193. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Continuous cover forestry (CCF) is a type of forest management which is based on ecological principles and avoids clearfelling as much as possible. A specialised form of CCF is the selection system which relies on inhomogeneous size structures in mixed-species forests and on the harvesting of individual dominant trees. The selection system was originally invented by upland farmers in Central Europe some 500 years ago and is fairly uncommon in Northern Europe. In our research, we studied two more or less mono-species Picea abies selection forests at Siljansfors in Central Sweden that have a comparatively low final stem diameter of 50 cm. We involved dynamic demographic equilibrium modelling to identify an ideal size structure as a reference that ensures sustainability. We compared this reference with the observed empirical stem-diameter distributions and found that both stands are indeed advancing towards the structure typical of single-tree selection systems. One stand is particularly close to this ideal, sustainable structure whilst the other requires more goal-orientated management in the future. Our research confirmed that selection forests with largely only one conifer species and a fairly small final diameter are possible at this latitude. We could also show that the dynamic demographic model can be converted to a simpler static model that is easier to apply in forest practice. Since selection stands are rare in Fennoscandia, the two stands studied at Siljansfors have been and will continue to be important research and management demonstration sites in the future.
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| 3. |
- Wagner, Leona, et al.
(författare)
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Neuropeptide Y (NPY) in cerebrospinal fluid from patients with Huntington's Disease : increased NPY levels and differential degradation of the NPY1-30 fragment
- 2016
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Ingår i: Journal of Neurochemistry. - : Wiley. - 1471-4159 .- 0022-3042. ; 137:5, s. 820-837
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Tidskriftsartikel (refereegranskat)abstract
- Huntington's disease (HD) is an inherited and fatal polyglutamine neurodegenerative disorder caused by an expansion of the CAG triplet repeat coding region within the HD gene. Progressive dysfunction and loss of striatal GABAergic medium spiny neurons (MSNs) may account for some of the characteristic symptoms in HD patients. Interestingly, in HD, MSNs expressing neuropeptide Y (NPY) are spared and their numbers is even up-regulated in HD patients. In line with this, we report here on increased immuno-linked NPY (IL-NPY) levels in human cerebrospinal fluid (hCSF) from HD patients. As this antibody-based detection of NPY may provide false positive differences due to the antibody-based detections of only fragments of NPY, the initial finding was validated by investigating the proteolytic stability of NPY in hCSF using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and selective inhibitors. A comparison between resulting NPY-fragments and detailed epitope analysis verified significant differences of IL-NPY1-36/3-36 and NPY1-30 levels between HD patients and control subjects. Ex vivo degradomics analysis demonstrated that NPY is initially degraded to NPY1-30 by cathepsin D (CTSD) in both HD patients and control subjects. Yet, NPY1-30 is then further differentially hydrolyzed by thimet oligopeptidase (TOP) in HD patients and by neprilysin (NEP) in control subjects. Furthermore, altered hCSF TOP-inhibitor Dynorphin A1-13 (Dyn-A1-13 ) and TOP-substrate Dyn-A1-8 levels indicate an impaired Dyn-A-TOP network in HD patients. Thus, we conclude that elevated IL-NPY-levels in conjunction with TOP- / NEP-activity/protein as well as Dyn-A1-13 -protein levels may serve as a potential biomarker in human CSF of HD. This article is protected by copyright. All rights reserved.
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| 4. |
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| 5. |
- Westbury, V, Michael, et al.
(författare)
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Hyena paleogenomes reveal a complex evolutionary history of cross-continental gene flow between spotted and cave hyena
- 2020
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 6:11
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Tidskriftsartikel (refereegranskat)abstract
- The genus Crocuta (African spotted and Eurasian cave hyenas) includes several closely related extinct and extant lineages. The relationships among these lineages, however, are contentious. Through the generation of population-level paleogenomes from late Pleistocene Eurasian cave hyena and genomes from modern African spotted hyena, we reveal the cross-continental evolutionary relationships between these enigmatic hyena lineages. We find a deep divergence (similar to 2.5 Ma) between African and Eurasian Crocuta populations, suggesting that ancestral Crocuta left Africa around the same time as early Homo. Moreover, we find discordance between nuclear and mitochondrial phylogenies and evidence for bidirectional gene flow between African and Eurasian Crocuta after the lineages split, which may have complicated prior taxonomic classifications. Last, we find a number of introgressed loci that attained high frequencies within the recipient lineage, suggesting some level of adaptive advantage from admixture.
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| 6. |
- Wutke, Saskia, et al.
(författare)
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Spotted phenotypes in horses lost attractiveness in the Middle Ages
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Horses have been valued for their diversity of coat colour since prehistoric times; this is especially the case since their domestication in the Caspian steppe in ∼3,500 BC. Although we can assume that human preferences were not constant, we have only anecdotal information about how domestic horses were influenced by humans. Our results from genotype analyses show a significant increase in spotted coats in early domestic horses (Copper Age to Iron Age). In contrast, medieval horses carried significantly fewer alleles for these phenotypes, whereas solid phenotypes (i.e., chestnut) became dominant. This shift may have been supported because of (i) pleiotropic disadvantages, (ii) a reduced need to separate domestic horses from their wild counterparts, (iii) a lower religious prestige, or (iv) novel developments in weaponry. These scenarios may have acted alone or in combination. However, the dominance of chestnut is a remarkable feature of the medieval horse population.
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| 7. |
- Wutke, Saskia, et al.
(författare)
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The origin of ambling horses
- 2016
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 26:15, s. 697-699
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Tidskriftsartikel (refereegranskat)abstract
- Horseback riding is the most fundamental use of domestic horses and has had a huge influence on the development of human societies for millennia. Over time, riding techniques and the style of riding improved. Therefore, horses with the ability to perform comfortable gaits (e.g. ambling or pacing), so-called ‘gaited’ horses, have been highly valued by humans, especially for long distance travel. Recently, the causative mutation for gaitedness in horses has been linked to a substitution causing a premature stop codon in the DMRT3 gene (DMRT3_Ser301STOP) [1]. In mice, Dmrt3 is expressed in spinal cord interneurons and plays an important role in the development of limb movement coordination [1]. Genotyping the position in 4396 modern horses from 141 breeds revealed that nowadays the mutated allele is distributed worldwide with an especially high frequency in gaited horses and breeds used for harness racing [2]. Here, we examine historic horse remains for the DMRT3 SNP, tracking the origin of gaitedness to Medieval England between 850 and 900 AD. The presence of the corresponding allele in Icelandic horses (9th–11th century) strongly suggests that ambling horses were brought from the British Isles to Iceland by Norse people. Considering the high frequency of the ambling allele in early Icelandic horses, we believe that Norse settlers selected for this comfortable mode of horse riding soon after arrival. The absence of the allele in samples from continental Europe (including Scandinavia) at this time implies that ambling horses may have spread from Iceland and maybe also the British Isles across the continent at a later date.
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