SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Jakobsson Mattias) ;pers:(Naidoo Thijessen)"

Sökning: WFRF:(Jakobsson Mattias) > Naidoo Thijessen

  • Resultat 1-9 av 9
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  •  
2.
  • Günther, Torsten, et al. (författare)
  • Ancient genomes link early farmers from Atapuerca in Spain to modern-day Basques
  • 2015
  • Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 112:38, s. 11917-11922
  • Tidskriftsartikel (refereegranskat)abstract
    • The consequences of the Neolithic transition in Europe-one of the most important cultural changes in human prehistory-is a subject of great interest. However, its effect on prehistoric and modern-day people in Iberia, the westernmost frontier of the European continent, remains unresolved. We present, to our knowledge, the first genome-wide sequence data from eight human remains, dated to between 5,500 and 3,500 years before present, excavated in the El Portalon cave at Sierra de Atapuerca, Spain. We show that these individuals emerged from the same ancestral gene pool as early farmers in other parts of Europe, suggesting that migration was the dominant mode of transferring farming practices throughout western Eurasia. In contrast to central and northern early European farmers, the Chalcolithic El Portalon individuals additionally mixed with local southwestern hunter-gatherers. The proportion of hunter-gatherer-related admixture into early farmers also increased over the course of two millennia. The Chalcolithic El Portalon individuals showed greatest genetic affinity to modern-day Basques, who have long been considered linguistic and genetic isolates linked to the Mesolithic whereas all other European early farmers show greater genetic similarity to modern-day Sardinians. These genetic links suggest that Basques and their language may be linked with the spread of agriculture during the Neolithic. Furthermore, all modern-day Iberian groups except the Basques display distinct admixture with Caucasus/Central Asian and North African groups, possibly related to historical migration events. The El Portalon genomes uncover important pieces of the demographic history of Iberia and Europe and reveal how prehistoric groups relate to modern-day people.
  •  
3.
  •  
4.
  •  
5.
  • Naidoo, Thijessen, et al. (författare)
  • Patterns of variation in cis-regulatory regions : examining evidence of purifying selection
  • 2018
  • Ingår i: BMC Genomics. - : BIOMED CENTRAL LTD. - 1471-2164. ; 19
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: With only 2 % of the human genome consisting of protein coding genes, functionality across the rest of the genome has been the subject of much debate. This has gained further impetus in recent years due to a rapidly growing catalogue of genomic elements, based primarily on biochemical signatures (e.g. the ENCODE project). While the assessment of functionality is a complex task, the presence of selection acting on a genomic region is a strong indicator of importance. In this study, we apply population genetic methods to investigate signals overlaying several classes of regulatory elements.Results: We disentangle signals of purifying selection acting directly on regulatory elements from the confounding factors of demography and purifying selection linked to e.g. nearby protein coding regions. We confirm the importance of regulatory regions proximal to coding sequence, while also finding differential levels of selection at distal regions. We note differences in purifying selection among transcription factor families. Signals of constraint at some genomic classes were also strongly dependent on their physical location relative to coding sequence. In addition, levels of selection efficacy across genomic classes differed between African and non-African populations.Conclusions: In order to assign a valid signal of selection to a particular class of genomic sequence, we show that it is crucial to isolate the signal by accounting for the effects of demography and linked-purifying selection. Our study highlights the intricate interplay of factors affecting signals of selection on functional elements.
  •  
6.
  • Naidoo, Thijessen, 1982- (författare)
  • Population Genetics of Human Genomic Elements
  • 2018
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The genomes of living organisms are composed of a multitude of functional units, which interact with each other and their environment in a highly regulated fashion, to facilitate the expression of an enduring (and evolving) phenotype. Several approaches have emerged in the effort to identify these functional units and explore their activities. In this thesis, I have taken a population genetics approach; evaluating how the distribution of genetic variation in the human genome has been shaped through the actions of natural selection on functional genomic elements. In the first paper, I interrogate a catalogue of elements derived from biochemical signatures for signals of selection; finding significant signals of purifying selection on regulatory elements, independent of linked-purifying selection. In the second paper, I explore the pseudogene class of genomic elements, and find that a large proportion of a particular subclass, transcribed duplicated pseudogenes, has experienced significant amounts of positive selection. In the third paper, I focus on protein coding genes and variants that disrupt their open reading frames. Specifically, I examine the distribution of loss-of-function variants in the Khoe-San population; gauging their functional significance and exploring the biological roles of affected genes. In the final paper, instead of using population genetics to uncover and explore genomic elements, I use a major genomic element – the Y chromosome – as an effective tool to study the evolutionary history of a human population.
  •  
7.
  •  
8.
  • Naidoo, Thijessen, et al. (författare)
  • Y-Chromosome Variation in Southern African Khoe-San Populations Based on Whole-Genome Sequences
  • 2020
  • Ingår i: Genome Biology and Evolution. - : Oxford University Press (OUP). - 1759-6653 .- 1759-6653. ; 12:7, s. 1031-1039
  • Tidskriftsartikel (refereegranskat)abstract
    • Although the human Y chromosome has effectively shown utility in uncovering facets of human evolution and population histories, the ascertainment bias present in early Y-chromosome variant data sets limited the accuracy of diversity and TMRCA estimates obtained from them. The advent of next-generation sequencing, however, has removed this bias and allowed for the discovery of thousands of new variants for use in improving the Y-chromosome phylogeny and computing estimates that are more accurate. Here, we describe the high-coverage sequencing of the whole Y chromosome in a data set of 19 male Khoe-San individuals in comparison with existing whole Y-chromosome sequence data. Due to the increased resolution, we potentially resolve the source of haplogroup B-P70 in the Khoe-San, and reconcile recently published haplogroup A-M51 data with the most recent version of the ISOGG Y-chromosome phylogeny. Our results also improve the positioning of tentatively placed new branches of the ISOGG Y-chromosome phylogeny. The distribution of major Y-chromosome haplogroups in the Khoe-San and other African groups coincide with the emerging picture of African demographic history; with E-M2 linked to the agriculturalist Bantu expansion, E-M35 linked to pastoralist eastern African migrations, B-M112 linked to earlier east-south gene flow, A-M14 linked to shared ancestry with central African rainforest hunter-gatherers, and A-M51 potentially unique to the Khoe-San.
  •  
9.
  • Schlebusch, Carina, 1977-, et al. (författare)
  • Khoe-San Genomes Reveal Unique Variation and Confirm the Deepest Population Divergence in Homo sapiens
  • 2020
  • Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 37:10, s. 2944-2954
  • Tidskriftsartikel (refereegranskat)abstract
    • The southern African indigenous Khoe-San populations harbor the most divergent lineages of all living peoples. Exploring their genomes is key to understanding deep human history. We sequenced 25 full genomes from five Khoe-San populations, revealing many novel variants, that 25% of variants are unique to the Khoe-San, and that the Khoe-San group harbors the greatest level of diversity across the globe. In line with previous studies, we found several gene regions with extreme values in genome-wide scans for selection, potentially caused by natural selection in the lineage leading to Homo sapiens and more recent in time. These gene regions included immunity-, sperm-, brain-, diet-, and muscle-related genes. When accounting for recent admixture, all Khoe-San groups display genetic diversity approaching the levels in other African groups and a reduction in effective population size starting around 100,000 years ago. Hence, all human groups show a reduction in effective population size commencing around the time of the Out-of-Africa migrations, which coincides with changes in the paleoclimate records, changes that potentially impacted all humans at the time.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-9 av 9

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy