Demographic history was a formative mechanism of the genetic structure for the taste receptor TAS2R16 in human populations inhabiting Africa's Sahel/Savannah Belt

2021 ◽  
Author(s):  
Iva Kulichová ◽  
Médéric Mouterde ◽  
Mohammed G. Mokhtar ◽  
Issa Diallo ◽  
Petr Tříska ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Demographic History ◽  
Taste Receptor ◽  
Human Populations

scholarly journals Low effective population size and high spatial genetic structure of black poplar populations from the Oder valley in Poland

2021 ◽  
Vol 78 (2) ◽  
Author(s):  
Błażej Wójkiewicz ◽  
Andrzewj Lewandowski ◽  
Weronika B. Żukowska ◽  
Monika Litkowiec ◽  
Witold Wachowiak
Keyword(s):  
Genetic Structure ◽  
Genetic Resources ◽  
Population Size ◽  
Effective Population Size ◽  
Spatial Genetic Structure ◽  
Demographic History ◽  
River Valley ◽  
Ex Situ ◽  
Effective Population ◽  
Black Poplar

Abstract Context Black poplar (Populus nigra L.) is a keystone species of European riparian ecosystems that has been negatively impacted by riverside urbanization for centuries. Consequently, it has become an endangered tree species in many European countries. The establishment of a suitable rescue plan of the remaining black poplar forest stands requires a preliminary knowledge about the distribution of genetic variation among species populations. However, for some parts of the P. nigra distribution in Europe, the genetic resources and demographic history remain poorly recognized. Aims Here, we present the first study on identifying and characterizing the genetic resources of black poplar from the Oder valley in Poland. This study (1) assessed the genetic variability and effective population size of populations and (2) examined whether gene flow is limited by distance or there is a single migrant pool along the studied river system. Methods A total of 582 poplar trees derived from nine black poplar populations were investigated with nuclear microsatellite markers. Results (1) The allelic richness and heterozygosity level were high and comparable between populations. (2) The genetic structure of the studied poplar stands was not homogenous. (3) The signatures of past bottlenecks were detected. Conclusion Our study (1) provides evidence for genetic substructuring of natural black poplar populations from the studied river catchment, which is not a frequent phenomenon reported for this species in Europe, and (2) indicates which poplar stands may serve as new genetic conservation units (GCUs) of this species in Europe. Key message The genetic resources of black poplar in the Oder River valley are still substantial compared to those reported for rivers in Western Europe. On the other hand, clear signals of isolation by distance and genetic erosion reflected in small effective population sizes and high spatial genetic structure of the analyzed populations were detected. Based on these findings, we recommend the in situ and ex situ conservation strategies for conserving and restoring the genetic resources of black poplar populations in this strongly transformed by human river valley ecosystem.

Genetic variability and demographic history of Heliothis virescens (Lepidoptera: Noctuidae) populations from Brazil inferred by mtDNA sequences

2011 ◽  
Vol 102 (3) ◽  
pp. 333-343 ◽  
Author(s):  
K.C. Albernaz ◽  
K.L. Silva-Brandão ◽  
P. Fresia ◽  
F.L. Cônsoli ◽  
C. Omoto
Keyword(s):  
Genetic Structure ◽  
Genetic Variability ◽  
Heliothis Virescens ◽  
Demographic History ◽  
Haplotype Diversity ◽  
Low Frequency ◽  
Haplotype Network ◽  
Demographic Expansion ◽  
Significant Genetic Structure ◽  
History Of

AbstractIntra- and inter-population genetic variability and the demographic history of Heliothis virescens (F.) populations were evaluated by using mtDNA markers (coxI, coxII and nad6) with samples from the major cotton- and soybean-producing regions in Brazil in the growing seasons 2007/08, 2008/09 and 2009/10. AMOVA indicated low and non-significant genetic structure, regardless of geographical scale, growing season or crop, with most of genetic variation occurring within populations. Clustering analyzes also indicated low genetic differentiation. The haplotype network obtained with combined datasets resulted in 35 haplotypes, with 28 exclusive occurrences, four of them sampled only from soybean fields. The minimum spanning network showed star-shaped structures typical of populations that underwent a recent demographic expansion. The recent expansion was supported by other demographic analyzes, such as the Bayesian skyline plot, the unimodal distribution of paired differences among mitochondrial sequences, and negative and significant values of neutrality tests for the Tajima's D and Fu's FS parameters. In addition, high values of haplotype diversity (Ĥ) and low values of nucleotide diversity (π), combined with a high number of low frequency haplotypes and values of θπ<θW, suggested a recent demographic expansion of H. virescens populations in Brazil. This demographic event could be responsible for the low genetic structure currently found; however, haplotypes present uniquely at the same geographic regions and from one specific host plant suggest an initial differentiation among H. virescens populations within Brazil.

scholarly journals An Ancient Baboon Genome Demonstrates Long-Term Population Continuity in Southern Africa

2020 ◽  
Vol 12 (4) ◽  
pp. 407-412 ◽  
Author(s):  
Iain Mathieson ◽  
Federico Abascal ◽  
Lasse Vinner ◽  
Pontus Skoglund ◽  
Cristina Pomilla ◽  
...  
Keyword(s):  
Southern Africa ◽  
Nonhuman Primates ◽  
Demographic History ◽  
Structured Populations ◽  
Human Populations ◽  
Papio Ursinus ◽  
Anthropological Research ◽  
Population Continuity ◽  
High Degree

Abstract Baboons are one of the most abundant large nonhuman primates and are widely studied in biomedical, behavioral, and anthropological research. Despite this, our knowledge of their evolutionary and demographic history remains incomplete. Here, we report a 0.9-fold coverage genome sequence from a 5800-year-old baboon from the site of Ha Makotoko in Lesotho. The ancient baboon is closely related to present-day Papio ursinus individuals from southern Africa—indicating a high degree of continuity in the southern African baboon population. This level of population continuity is rare in recent human populations but may provide a good model for the evolution of Homo and other large primates over similar timespans in structured populations throughout Africa.

scholarly journals The Genetic History of France

2019 ◽  
Author(s):  
Aude Saint Pierre ◽  
Joanna Giemza ◽  
Matilde Karakachoff ◽  
Isabel Alves ◽  
Philippe Amouyel ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Demographic History ◽  
Migration Routes ◽  
Effective Population ◽  
Genetic Studies ◽  
Independent Population ◽  
Genome Wide Data ◽  
Population Sizes ◽  
History Of ◽  
Exhaustive Study

ABSTRACTThe study of the genetic structure of different countries within Europe has provided significant insights into their demographic history and their actual stratification. Although France occupies a particular location at the end of the European peninsula and at the crossroads of migration routes, few population genetic studies have been conducted so far with genome-wide data. In this study, we analyzed SNP-chip genetic data from 2 184 individuals born in France who were enrolled in two independent population cohorts. Using FineStructure, six different genetic clusters of individuals were found that were very consistent between the two cohorts. These clusters match extremely well the geography and overlap with historical and linguistic divisions of France. By modeling the relationship between genetics and geography using EEMS software, we were able to detect gene flow barriers that are similar in the two cohorts and corresponds to major French rivers or mountains. Estimations of effective population sizes using IBDNe program also revealed very similar patterns in both cohorts with a rapid increase of effective population sizes over the last 150 generations similar to what was observed in other European countries. A marked bottleneck is also consistently seen in the two datasets starting in the fourteenth century when the Black Death raged in Europe. In conclusion, by performing the first exhaustive study of the genetic structure of France, we fill a gap in the genetic studies in Europe that would be useful to medical geneticists but also historians and archeologists.

scholarly journals Demographic history shaped geographical patterns of deleterious mutation load in a broadly distributed Pacific Salmon

2019 ◽  
Author(s):  
Quentin Rougemont ◽  
Jean-Sébastien Moore ◽  
Thibault Leroy ◽  
Eric Normandeau ◽  
Eric B. Rondeau ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Demographic History ◽  
Glacial Refugium ◽  
Human Populations ◽  
Deleterious Mutations ◽  
Effective Population ◽  
Geographical Patterns ◽  
Genome Wide Data

AbstractA thorough reconstruction of historical processes is essential for a comprehensive understanding the mechanisms shaping patterns of genetic diversity. Indeed, past and current conditions influencing effective population size have important evolutionary implications for the efficacy of selection, increased accumulation of deleterious mutations, and loss of adaptive potential. Here, we gather extensive genome-wide data that represent the extant diversity of the Coho salmon (Oncorhynchus kisutch) to address two objectives. We demonstrate that a single glacial refugium is the source of most of the present-day genetic diversity, with detectable inputs from a putative secondary micro-refugium. We found statistical support for a scenario whereby ancestral populations located south of the ice sheets expanded in postglacial time, swamping out most of the diversity from other putative micro-refugia. Demographic inferences revealed that genetic diversity was also affected by linked selection in large parts of the genome. Moreover, we demonstrate that the recent demographic history of this species generated regional differences in the load of deleterious mutations among populations, a finding that mirrors recent results from human populations and provides increased support for models of expansion load. We propose that insights from these historical inferences should be better integrated in conservation planning of wild organisms, which currently focuses largely on neutral genetic diversity and local adaptation, with the role of potentially maladaptive variation being generally ignored.

scholarly journals Population Genetic Structure of the Invasive Spotted Alfalfa Aphid Therioaphis trifolii (Hemiptera: Aphididae) in China Inferred From Complete Mitochondrial Genomes

2021 ◽  
Vol 9 ◽  
Author(s):  
Xinzhi Liu ◽  
Shuhua Wei ◽  
Zhenyong Du ◽  
Jia He ◽  
Xinyue Zhang ◽  
...  
Keyword(s):  
Invasive Species ◽  
Genetic Structure ◽  
Population Genetic ◽  
High Throughput Sequencing ◽  
Demographic History ◽  
Complete Mitochondrial Genome ◽  
Haplotype Diversity ◽  
Evolutionary Process ◽  
Invasion History ◽  
Ecosystem Integrity

Biological invasions represent a natural rapid evolutionary process in which invasive species may present a major threat to biodiversity and ecosystem integrity. Analyzing the genetic structure and demographic history of invaded populations is critical for the effective management of invasive species. The spotted alfalfa aphid (SAA) Therioaphis trifolii is indigenous in the Mediterranean region of Europe and Africa and has invaded China, causing severe damages to the alfalfa industry. However, little is known about its genetic structure and invasion history. In this study, we obtained 167 complete mitochondrial genome sequences from 23 SAA populations across China based on high-throughput sequencing and performed population genetic and phylogenomic analyses. High haplotype diversity and low nucleotide diversity were found in SAA populations in China with distinct genetic structures, i.e., all populations diverged into three phylogenetic lineages. Demographic history analyses showed a recent expansion of the SAA population, consistent with the recent invasion history. Our study indicated that SAA may have invaded through multiple introduction events during commercial trades of alfalfa, although this needs further validation by nuclear markers.

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