scholarly journals Biogeographically significant units in conservation: a new integrative concept for conserving ecological and evolutionary processes

2019 ◽  
Vol 46 (4) ◽  
pp. 293-301 ◽  
Author(s):  
M Paula Quiroga ◽  
Lucia Castello ◽  
Vilma Quipildor ◽  
Andrea C Premoli
Keyword(s):  
Genetic Structure ◽  
Strong Association ◽  
Geographic Region ◽  
Landscape Conservation ◽  
Major Barrier ◽  
Distribution Maps ◽  
Genetic Barriers ◽  
Bibliographic Search ◽  
Molecular Information ◽  
Integrative Concept

SummaryWe combined tools of phylogeography, population genetics and biogeographical interpretation to analyse a group of phylogenetically independent lineages (animals and plants) that coexist within the same geographical region, yet under markedly different environments, in order to identify generalized barriers for gene flow. We tested the hypothesis that major geographic features have produced a concordant genetic structure in phylogenetically independent lineages. A rigorous bibliographic search was performed, selecting available molecular information from six taxa occupying distinct southern biomes of South America: Yungas, Prepuna, Puna and northern Monte. We estimated within-population genetic diversity, the genetic structure and haplotype phylogenies to assemble distribution maps of genetic barriers for each species. We found a strong association between genetic variation and latitudinal distribution of populations. We detected a major barrier for six taxa at 27°S latitude and a second one for a group of three species at 25–26°S. Two alternative non-exclusive hypotheses – geology and/or climate – explain concordant genetic barriers in divergent lineages. We suggest that the term ‘biogeographically significant units’ portrays a group of populations of phylogenetically unrelated taxa that inhabit the same geographic region that have been similarly impacted by major physical events, which can be used to identify priority areas in landscape conservation.

scholarly journals Using neutral and outlier loci to uncover the genetic structure of 'Mytilus galloprovincialis' populations from the eastern Adriatic coast using population genetic and seascape genetic approaches

2021 ◽  
Author(s):  
◽  
Joanna Szondy Hamilton
Keyword(s):  
Genetic Structure ◽  
Mytilus Galloprovincialis ◽  
Blue Mussel ◽  
Strong Association ◽  
Outlier Locus ◽  
Outlier Loci ◽  
Adriatic Coast ◽  
Low Levels ◽  
Polymorphic Microsatellite ◽  
Highly Correlated

<p>The genetic variation of the Mediterranean blue mussel, Mytilus galloprovincialis from the eastern coastline of the Adriatic Sea was investigated using polymorphic microsatellite markers. In total, 843 individuals were sampled from 18 populations representing a variety of coastal environments in Croatia, Bosnia-Herzegovina, Montenegro and Albania. Neutral loci revealed low levels of genetic structure in this continuously distributed species, while one outlier locus, MGE7, which may be under selection, provided strong evidence of genetic structure. The distribution of one of the alleles of this locus, MGE7²⁴³, was significantly correlated with latitude. A genetic seascape analysis using 9 environmental and 3 geospatial variables revealed a strong association between MGE7²⁴³ and three highly correlated environmental variables, maximum sea surface temperature, minimum salinity and maximum chlorophyll-a. This association was maintained for homozygous genotypes for the MGE7²⁴³ allele, but not for heterozygotes, providing further evidence that the locus MGE7 may be under selection or closely linked to a gene under selection. These findings highlight how previously unrecognised genetic structure can be identified through the use of genetic seascape approaches.</p>

scholarly journals Geographic patterns of human allele frequency variation: a variant-centric perspective

2020 ◽  
Author(s):  
Arjun Biddanda ◽  
Daniel P. Rice ◽  
John Novembre
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Structure ◽  
Allele Frequency ◽  
Human Genetics ◽  
Geographic Region ◽  
Frequency Variation ◽  
Human Genetic Variation ◽  
Alternative Representation ◽  
Geographic Patterns

AbstractA key challenge in human genetics is to describe and understand the distribution of human genetic variation. Often genetic variation is described by showing relationships among populations or individuals, in each case drawing inferences over a large number of variants. Here, we present an alternative representation of human genetic variation that reveals the relative abundance of different allele frequency patterns across populations. This approach allows viewers to easily see several features of human genetic structure: (1) most variants are rare and geographically localized, (2) variants that are common in a single geographic region are more likely to be shared across the globe than to be private to that region, and (3) where two individuals differ, it is most often due to variants that are common globally, regardless of whether the individuals are from the same region or different regions. To guide interpretation of the results, we also apply the visualization to contrasting theoretical scenarios with varying levels of divergence and gene flow. Our variant-centric visualization clarifies the major geographic patterns of human variation and can be used to help correct potential misconceptions about the extent and nature of genetic differentiation among populations.

scholarly journals Reconstructing the human genetic history of mainland Southeast Asia: insights from genome-wide data from Thailand and Laos

2020 ◽  
Author(s):  
Wibhu Kutanan ◽  
Dang Liu ◽  
Jatupol Kampuansai ◽  
Metawee Srikummool ◽  
Suparat Srithawong ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Southeast Asia ◽  
Geographic Region ◽  
Whole Genome Sequence ◽  
Genetic History ◽  
Asian Populations ◽  
Genome Wide ◽  
Population Interactions ◽  
Hill Tribes ◽  
Mainland Southeast Asia

AbstractThailand and Laos, located in the center of Mainland Southeast Asia (MSEA), harbor diverse ethnolinguistic groups encompassing all five language families of MSEA: Tai-Kadai (TK), Austroasiatic (AA), Sino-Tibetan (ST), Hmong-Mien (HM) and Austronesian (AN). Previous genetic studies of Thai/Lao populations have focused almost exclusively on uniparental markers and there is a paucity of genome-wide studies. We therefore generated genome-wide SNP data for 33 ethnolinguistic groups, belonging to the five MSEA language families from Thailand and Laos, and analysed these together with data from modern Asian populations and SEA ancient samples. Overall, we find genetic structure according to language family, albeit with heterogeneity in the AA-, HM- and ST-speaking groups, and in the hill tribes, that reflects both population interactions and genetic drift. For the TK speaking groups, we find localized genetic structure that is driven by different levels of interaction with other groups in the same geographic region. Several Thai groups exhibit admixture from South Asia, which we date to ∼600-1000 years ago, corresponding to a time of intensive international trade networks that had a major cultural impact on Thailand. An AN group from Southern Thailand shows both South Asian admixture as well as overall affinities with AA-speaking groups in the region, suggesting an impact of cultural diffusion. Overall, we provide the first detailed insights into the genetic profiles of Thai/Lao ethnolinguistic groups, which should be helpful for reconstructing human genetic history in MSEA and selecting populations for participation in ongoing whole genome sequence and biomedical studies.

scholarly journals Racial differences in two measures of trust in biomedical research

2019 ◽  
Vol 3 (2-3) ◽  
pp. 113-119 ◽  
Author(s):  
Jennifer Cunningham-Erves ◽  
Victoria Villalta-Gil ◽  
Kenneth A. Wallston ◽  
Alaina P. Boyer ◽  
Consuelo H. Wilkins
Keyword(s):  
Socioeconomic Status ◽  
Racial Differences ◽  
Biomedical Research ◽  
Strong Association ◽  
Research Participation ◽  
Demographic Variables ◽  
The Other ◽  
Convenience Sample ◽  
Major Barrier ◽  
Item Scores

AbstractObjective:Lack of trust toward medical research is a major barrier to research participation, particularly among some population groups. Valid measures of trust are needed to develop appropriate interventions. The study purpose was to compare two previously validated scales that measure trust in biomedical research – one developed by Hall et al. (H-TBR; 2006) and the other by Mainous et al. (M-TBR; 2006) – in relation to socio-demographic variables and attitudes toward research. Differences between Black and White respondents were explored.Methods:Two nearly identical surveys – one with H-TBR and the other with M-TBR – were systematically administered to a convenience sample. Internal consistency reliability of each scale was assessed. Associations were computed between scores on each scale with attitudes toward biomedical research and demographic variables (i.e., gender, age, race, and socioeconomic status). The difference between White and Black respondents on each TBR score while controlling for age, education, and race was also investigated.Results:A total of 2020 participants completed the H-TBR survey; 1957 completed the M-TBR survey. Mean item scores for M-TBR were higher (F = 56.05, p < 0.001) among Whites than Blacks. Whites also had higher mean item scores than Blacks on H-TBR (F = 7.09, p < 0.001). Both scales showed a strong association with participants’ perceived barriers to research (ps < 0.001) and significant, positive correlations with interest in research participation (ps < 0.001). Age and household income were positive predictors of TBR scores, but the effects of education differed.Conclusions:Both scales are internally consistent and show associations with attitudes toward research. Whites score higher than Blacks on both TBR scales, even while controlling for age and socioeconomic status.

scholarly journals Genetic and Virulence Analysis of Rhizoctonia spp. Associated with Sugar Beet Root and Crown Rot in the Northeast Region of Iran

Plant Disease ◽  
2012 ◽  
Vol 96 (3) ◽  
pp. 398-408 ◽  
Author(s):  
Parissa Taheri ◽  
Saeed Tarighi
Keyword(s):  
Genetic Structure ◽  
Sugar Beet ◽  
Anastomosis Group ◽  
Geographic Region ◽  
Crown Rot ◽  
Aflp Data ◽  
Beet Root ◽  
Root And Crown Rot ◽  
Sugar Beet Root ◽  
And Cluster Analysis

Rhizoctonia spp. are the main causal agents of root and crown rot on sugar beet. In this study, isolates of Rhizoctonia spp. were obtained from diseased sugar beet in Iran over 2 years. Of 68 isolates, 61 were R. solani and 7 were R. cerealis. The anastomosis group (AG) of all isolates was determined on glass slides against the testers. Characterization of intraspecific groups (ISGs) of R. solani isolates revealed that, of 61 isolates, 43 were AG2-2 IIIB and 18 were AG2-2 IV. Amplified fragment length polymorphism (AFLP) analyses were used to investigate genetic structure of Rhizoctonia populations. Principal coordinate plots and cluster analysis differentiated R. solani from R. cerealis isolates and separated the R. solani isolates belonging to different ISGs. AFLP data indicated that the R. solani and R. cerealis populations are not clonal. Analysis of molecular variance in AG2-2 IIIB isolates showed that geographic region was the main factor determining genetic structure of the populations. Sampling year had no significant effect on the genotypes. Pathogenicity tests on Beta vulgaris ‘FD0432’ revealed that R. solani AG2-2 IIIB and AG2-2 IV isolates were more virulent than R. cerealis.

scholarly journals Unraveling the genetic structure of the coconut scale insect pest (Aspidiotus rigidus Reyne) outbreak populations in the Philippines

2019 ◽  
Author(s):  
Joeselle M. Serrana ◽  
Naoto Ishitani ◽  
Thaddeus M. Carvajal ◽  
Billy Joel M. Almarinez ◽  
Alberto T. Barrion ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Genetic Differentiation ◽  
Demographic History ◽  
Insect Pest ◽  
Scale Insect ◽  
The Philippines ◽  
Geographic Region ◽  
Invasive Pest ◽  
Economic Losses ◽  
History Of

AbstractThe Philippines suffered from a devastating outbreak of the coconut scale insect pest, Aspidiotus rigidus Reyne inflicting significant economic losses to the country’s coconut industry. Despite the massive outbreak, little is known about the population and dispersal history of this invasive pest in the Philippines. Here, we examined the genetic diversity, structure and demographic history of A. rigidus sampled from localities with reported outbreaks from 2014 to 2017. We analyzed the genetic structure of seven A. rigidus outbreak populations using mitochondrial COI and nuclear EF-1α markers. Both markers and all methods of population genetic structure analyses indicate clear differentiation among the A. rigidus populations separating the northern (i.e., Luzon provinces) from the southern (i.e., Basilan and Zamboanga Peninsula) regions of the Philippines. Very low or no genetic differentiation was observed within and amongst the populations per geographic region indicating two unrelated outbreak events of the pest originating from two genetically uniform populations isolated in each respective region. Historical data supports the resurgence of an established A. rigidus population in the south which could have been driven by sudden climatic changes or human-induced habitat imbalance. Given no historical information, we disregard the possible resurgence from the northern population and infer that the outbreak could have resulted from a recent introduction of a non-native A. rigidus in the region. Our study provides valuable information on the genetic differentiation of the two A. rigidus groups that would be useful for developing and implementing biological control strategies against this pest in the Philippines.

scholarly journals The genetic structure of Scots pine (Pinus sylvestris L.) population from the top of Szczeliniec Wielki Mt., Central Sudetes

2014 ◽  
Vol 63 (3-4) ◽  
pp. 315-324 ◽  
Author(s):  
Jerzy Szweykowski ◽  
Wiesław Prus-Głowacki ◽  
Jerzy Hrynkiewicz
Keyword(s):  
Genetic Structure ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Environmental Conditions ◽  
Genetic Parameters ◽  
Geographic Region ◽  
Common Origin ◽  
Provenance Trial ◽  
Great Similarity

The comparison of the genetic stucture of the population of Scots pine from Szczeliniec Wielki Mt. with the population of its progeny and three other populations from the same geographic region shows great similarity of both populations as far as the frequencies of genes and genotypes are concerned. Also other genetic parameters, such as heterozygosity, genotypic polymorphism indices and a number of alleles per locus were in both populations very similar. It seems that our data proved that the provenance trial experiments reflect rather closely the genetic structure of maternal populations. The fact that the population from Szczeliniec Wielki and its "replica" are genetically most similar to the geographically closest population from Bystrzyca Kłodzka leads to the conclusion, that these populations are of common origin. Though the relic character of the population from Szczeliniec can not be excluded. The morphological distinctness of the population from Szczeliniec is caused by a modifying influence of environmental conditions.

scholarly journals Gene Variants Associated With Venous Thrombosis: A Replication Study in a Brazilian Multicentre Study

2020 ◽  
Vol 26 ◽  
pp. 107602962096222
Author(s):  
Anna Virgínia Calazans Romano ◽  
Aline Barnabé ◽  
Telma Barbosa Gadelha ◽  
João Carlos de Campos Guerra ◽  
Rodrigo Secolin ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Genetic Variability ◽  
Statistical Power ◽  
Case Control Study ◽  
Association Studies ◽  
Case Control ◽  
Geographic Region ◽  
Brazilian Population ◽  
Nucleotide Polymorphisms ◽  
Control Study

Single nucleotide polymorphisms (SNP) associated with Venous Thromboembolism (VTE) risk have been identified in European and American populations. Replicate SNPs associated with VTE in a Brazilian multicenter case-control study of the Southeast region. Patients with previous VTE assisted at the Outpatient Clinics of 3 centers of the Southeast Brazilian region were compared to normal controls of the same geographic region. We evaluated 29 SNPs associated with VTE risk in other populations, and 90 SNPs for stratification analysis of the population. Due to high admixture of Brazilian population and lack of previous studies, the calculation of the sample power was performed after genotyping. Sample size, allelic frequency and Hardy-Weinberg equilibrium were estimated. The association and odds ratio analyses were estimated by logistic regression and the results were adjusted for multiple tests using Bonferroni correction. The evaluation of the genetic structure similarity in the cases and controls was performed by AMOVA. 436 cases and 430 controls were included. It was demonstrated that this sample has a statistical power to detect a genetic association of 79.4%. AMOVA showed that the genetic variability between groups was 0.0% and 100% within each group. None of the SNPs showed association with VTE in our population. A Brazilian multicenter case-control study with adequate sample power, high genetic variability though no stratification between groups, showed no replication of SNPs associated with VTE. The high admixture of Brazilian population may be responsible for these results, emphasizing the influence of the population genetic structure in association studies.

CHANGES IN THE GENETIC STRUCTURE OF A VALLEY IN THE PYRENEES (CATALONIA, SPAIN)

2016 ◽  
Vol 49 (1) ◽  
pp. 69-82
Author(s):  
Alejandra Toledo ◽  
Leyre Pámpanas ◽  
David García ◽  
Davide Pettener ◽  
Antonio González-Martin
Keyword(s):  
Genetic Structure ◽  
Diversity Index ◽  
Gender Diversity ◽  
Livestock Farming ◽  
Interesting Phenomenon ◽  
The Social ◽  
Genetic Barriers ◽  
Biological History ◽  
Second Period ◽  
Migrant Groups

SummaryIn some situations the use of isonymy is the best strategy for studying the genetic structure of a population and its biological history. In this study different population parameters were calculated for one of the most isolated valleys in the Pyrenees – the region of the Alta Ribagorça in Catalonia, Spain. Surnames from marriage records covering the continuous period from 1638 to 1988 were used. From 1950 onwards this region underwent important social, economic and biological changes related to the introduction of hydroelectric and mining industries, and the change from livestock farming to a society based on services. Two periods were analysed (1638–1950 and 1951–1988) allowing population changes that occurred in the region to be determined. The study focused on calculating the number of surnames by gender, diversity index (H), population sub-structure (RP−RPr)/RPr and inbreeding coefficient (Ft) and detection of possible genetic barriers. The results demonstrate the importance that geography initially had in shaping the genetic structure of the population and how this was gradually replaced by other parameters such as roads or the social and economic importance of towns. An interesting phenomenon is that inbreeding has traditionally been associated with rural life, isolation and endogamy. However, for the Alta Ribagorça it was observed that in the second period, 1951–1988, inbreeding mainly depended on the composition of migrant groups and the reaction of the native population to the arrival of migrants from outside the region.

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