scholarly journals Comparison of the effectiveness of ISJ and SSR markers and detection of outlier loci in conservation genetics ofPulsatilla patenspopulations

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2504 ◽  
Author(s):  
Katarzyna Bilska ◽  
Monika Szczecińska
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Conservation Genetics ◽  
Ssr Markers ◽  
Full Range ◽  
Mantel Test ◽  
Evolutionary Potential ◽  
Functional Variation ◽  
Genetics Research ◽  
Outlier Loci

BackgroundResearch into the protection of rare and endangered plant species involves genetic analyses to determine their genetic variation and genetic structure. Various categories of genetic markers are used for this purpose. Microsatellites, also known as simple sequence repeats (SSR), are the most popular category of markers in population genetics research. In most cases, microsatellites account for a large part of the noncoding DNA and exert a neutral effect on the genome. Neutrality is a desirable feature in evaluations of genetic differences between populations, but it does not support analyses of a population’s ability to adapt to a given environment or its evolutionary potential. Despite the numerous advantages of microsatellites, non-neutral markers may supply important information in conservation genetics research. They are used to evaluate adaptation to specific environmental conditions and a population’s adaptive potential. The aim of this study was to compare the level of genetic variation inPulsatilla patenspopulations revealed by neutral SSR markers and putatively adaptive ISJ markers (intron-exon splice junction).MethodsThe experiment was conducted on 14 Polish populations ofP. patensand threeP. patenspopulations from the nearby region of Vitebsk in Belarus. A total of 345 individuals were examined. Analyses were performed with the use of eight SSR primers specific toP. patensand three ISJ primers.ResultsSSR markers revealed a higher level of genetic variation than ISJ markers (He= 0.609,He= 0.145, respectively). An analysis of molecular variance (AMOVA) revealed that, the overall genetic diversity between the analyzed populations defined by parametersFSTand ΦPTfor SSR (20%) and ΦPTfor ISJ (21%) markers was similar. Analysis conducted in theStructureprogram divided analyzed populations into two groups (SSR loci) and three groups (ISJ markers). Mantel test revealed correlations between the geographic distance and genetic diversity of Polish populations ofP. patensfor ISJ markers, but not for SSR markers.ConclusionsThe results of the present study suggest that ISJ markers can complement the analyses based on SSRs. However, neutral and adaptive markers should not be alternatively applied. Neutral microsatellite markers cannot depict the full range of genetic variation in a population because they do not enable to analyze functional variation. Although ISJ markers are less polymorphic, they can contribute to the reliability of analyses based on SSRs.

scholarly journals Genetic Diversity and Population Structure of 93 Rice Cultivars (Lines) (Oryza Sativa Xian Group) in Qinba in China by 3 Types of Genetic Markers

2021 ◽  
Author(s):  
Yu Zhang ◽  
Yewen Wang ◽  
Peijiang Li ◽  
Yuexing Wang ◽  
Shimao Zheng ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Genetic Markers ◽  
Ssr Markers ◽  
Diversity Index ◽  
Indica Rice ◽  
Mantel Test ◽  
Phenotypic Traits ◽  
Phenotypic Analysis

Abstract Background: The Qinba region is the transition region between Indica and Japonica varieties in China. It has a long history of Indica rice planting of more than 7000 years and is also a planting area for fine-quality Indica rice. The aims of this study are to explore different genetic markers applied to the analysis population structure, genetic diversity, selection and optimization of molecular markers of Indica rice, thus providing more information for the protection and utilization on germplasm resources of Indica rice. Methods: 15 phenotypic traits, a core set of 48 SSR markers as well as SNPs data obtained by genotyping-by-sequencing (GBS, NlaIII and MseI digestion, referred to as SNPs-NlaIII and SNPs-MseI, respectively) for this panel of 93 samples using the Illumina HiSeq2000 sequencing platform, were employed to explore the genetic diversity and population structure of 93 samples.Results: The average of coefficient of variation (CV) and diversity index (He) were 29.72% and 1.83 ranging from 3.07% to 137.43%, and from 1.45 to 2.03, respectively. The correlation coefficient between 15 phenotypic traits ranged from 0.984 to -0.604. The first four PCs accounted for 70.693% phenotypic variation based on phenotypic analysis. A total of 379 alleles were obtained using SSR markers, encompassing an average of 8.0 alleles per primer. Polymorphic bands (PPB) and polymorphism information content (PIC) was 88.65% and 0.77, respectively. The Mantel test showed that the correlation between the genetic distance matrix based on SNPs-NlaIII and SNPs-MseI was the largest (R2=0.88), and that based on 15 phenotypic traits and SSR was the smallest (R2=0.09). The 93 samples could be clustered into two subgroups by 3 types of genetic markers. Molecular variance analysis revealed that the genetic variation was 2% among populations and 98% within populations (the Nm was 0.16), Tajima’s D value was 1.66, the FST between the two populations was 0.61 based on 72,824 SNPs. Conclusions: The population genetic variation explained by SNPs was larger than that explained by SSRs. The gene flow of 93 samples used in this study was larger than that of naturally self-pollinated crops, which may be caused by long-term breeding selection of Indica rice in the Qinba region. The genetic structure of the 93 samples was simple and lacked rare alleles.

scholarly journals Genetic Diversity and Population Structure of 93 Rice Cultivars (Lines) (Oryza Sativa Xian Group) in Qinba in China By 3 Types of Genetic Markers

2022 ◽  
Author(s):  
Yu Zhang ◽  
Qiaoqiao He ◽  
Xixi Zhou ◽  
Yewen Wang ◽  
Peijiang Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Genetic Markers ◽  
Ssr Markers ◽  
Diversity Index ◽  
Indica Rice ◽  
Mantel Test ◽  
Phenotypic Traits ◽  
Phenotypic Analysis

Abstract Background: The Qinba region is the transition region between Indica and Japonica varieties in China. It has a long history of Indica rice planting of more than 7000 years and is also a planting area for fine-quality Indica rice. The aims of this study are to explore different genetic markers applied to the analysis population structure, genetic diversity, selection and optimization of molecular markers of Indica rice, thus providing more information for the protection and utilization on germplasm resources of Indica rice. Methods: 15 phenotypic traits, a core set of 48 SSR markers as well as SNPs data obtained by genotyping-by-sequencing (GBS, NlaIII and MseI digestion, referred to as SNPs-NlaIII and SNPs-MseI, respectively) for this panel of 93 samples using the Illumina HiSeq2000 sequencing platform, were employed to explore the genetic diversity and population structure of 93 samples.Results: The average of coefficient of variation (CV) and diversity index (He) were 29.72% and 1.83 ranging from 3.07% to 137.43%, and from 1.45 to 2.03, respectively. The correlation coefficient between 15 phenotypic traits ranged from 0.984 to -0.604. The first four PCs accounted for 70.693% phenotypic variation based on phenotypic analysis. A total of 379 alleles were obtained using SSR markers, encompassing an average of 8.0 alleles per primer. Polymorphic bands (PPB) and polymorphism information content (PIC) was 88.65% and 0.77, respectively. The Mantel test showed that the correlation between the genetic distance matrix based on SNPs-NlaIII and SNPs-MseI was the largest (R2=0.88), and that based on 15 phenotypic traits and SSR was the smallest (R2=0.09). The 93 samples could be clustered into two subgroups by 3 types of genetic markers. Molecular variance analysis revealed that the genetic variation was 2% among populations and 98% within populations (the Nm was 0.16), Tajima’s D value was 1.66, the FST between the two populations was 0.61 based on 72,824 SNPs. Conclusions: The population genetic variation explained by SNPs was larger than that explained by SSRs. The gene flow of 93 samples used in this study was larger than that of naturally self-pollinated crops, which may be caused by long-term breeding selection of Indica rice in the Qinba region. The genetic structure of the 93 samples was simple and lacked rare alleles.

Conservation genetics and ecology of the endangered rainforest shrub, Triunia robusta, from the Sunshine Coast, Australia

2002 ◽  
Vol 50 (1) ◽  
pp. 93 ◽  
Author(s):  
Alison Shapcott
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Conservation Genetics ◽  
Population Size ◽  
Genetic Similarity ◽  
Small Region ◽  
Geographic Proximity ◽  
Close Proximity ◽  
The Mean

Triunia robusta, which until recently was thought to be extinct, is now classified nationally as endangered. It is an understorey species restricted to the subcoastal rainforests in a small region of the Sunshine Coast, Queensland. The project involved sampling the genetic variation and measuring the population size and size distribution of T. robusta and its geographically closest congener T. youngiana, which occurs further south and has a wider geographic distribution. A total of 877 T. robusta plants were recorded across the 11 populations, approximately half (56.8%) of these were juveniles less than 1 m tall, whereas in T. youngiana only about 36.4% of a population was composed of juveniles. Genetic diversity was similar but significantly higher for T. robusta than T. youngiana if the very small T. robusta populations (2 or 3 plants) were excluded from analysis (P < 0.05). The mean percentage of polymorphic loci among populations was high for both species. Triunia robusta is not, on average, more inbred than the more common T. youngiana. There was more differentiation between the T. robusta populations, which were in close proximity, than between the more geographically separated T. youngiana populations. Thus, there is evidence of more gene flow between populations of T. youngiana than between those of T. robusta. However, there was no geographic relationship between genetic similarity and geographic proximity in T. robusta

scholarly journals Genetic structure correlates with ethnolinguistic diversity in eastern and southern Africa

2021 ◽  
Author(s):  
Elizabeth G. Atkinson ◽  
Shareefa Dalvie ◽  
Yakov Pichkar ◽  
Allan Kalungi ◽  
Lerato Majara ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Variant Interpretation ◽  
African Continent ◽  
Transmission Rates ◽  
Genetics Research ◽  
African Populations ◽  
The World ◽  
Eastern And Southern Africa ◽  
Language Transmission

African populations are the most diverse in the world yet are sorely underrepresented in medical genetics research. Here, we examine the structure of African populations using genetic and comprehensive multigenerational ethnolinguistic data from the Neuropsychiatric Genetics of African Populations-Psychosis study (NeuroGAP-Psychosis) consisting of 900 individuals from Ethiopia, Kenya, South Africa, and Uganda. We find that self-reported language classifications meaningfully tag underlying genetic variation that would be missed with consideration of geography alone, highlighting the importance of culture in shaping genetic diversity. Leveraging our uniquely rich multi-generational ethnolinguistic metadata, we track language transmission through the pedigree, observing the disappearance of several languages in our cohort as well as notable shifts in frequency over three generations. We further find significantly higher language transmission rates for matrilineal groups as compared to patrilineal. We highlight both the diversity of variation within the African continent, as well as how within-Africa variation can be informative for broader variant interpretation; many variants appearing rare elsewhere are common in parts of Africa. The work presented here improves the understanding of the spectrum of genetic variation in African populations and highlights the enormous and complex genetic and ethnolinguistic diversity within Africa.

scholarly journals Genotyping-by-sequencing reveals the effects of riverscape, climate and interspecific introgression on the genetic diversity and local adaptation of the endangered Mexican golden trout (Oncorhynchus chrysogaster)

2018 ◽  
Author(s):  
Marco A. Escalante ◽  
Charles Perrier ◽  
Francisco J. García-De León ◽  
Arturo Ruiz-Luna ◽  
Enrique Ortega-Abboud ◽  
...  
Keyword(s):  
Climate Change ◽  
Genetic Diversity ◽  
Genetic Variation ◽  
Local Adaptation ◽  
Population Genomics ◽  
Landscape Heterogeneity ◽  
Genotyping By Sequencing ◽  
Anthropogenic Factors ◽  
Nucleotide Polymorphisms ◽  
Evolutionary Potential

AbstractHow environmental and anthropogenic factors influence genetic variation and local adaptation is a central issue in evolutionary biology. The Mexican golden trout (Oncorhynchus chrysogaster), one of the southernmost native salmonid species in the world, is susceptible to climate change, habitat perturbations and the competition and hybridization with exotic rainbow trout (O. mykiss). The present study aimed for the first time to use genotyping-by-sequencing to explore the effect of genetic hybridization with O. mykiss and of riverscape and climatic variables on the genetic variation among O. chrysogaster populations. Genotyping-by-sequencing (GBS) was applied to generate 9767 single nucleotide polymorphisms (SNPs), genotyping 272 O. chrysogaster and O. mykiss. Population genomics analyses were combined with landscape ecology approaches into a riverine context (riverscape genetics). The clustering analyses detected seven different genetic groups (six for O. chrysogater and one for aquaculture O. mykiss) and a small amount of admixture between aquaculture and native trout with only two native genetic clusters showing exotic introgression. Latitude and precipitation of the driest month had a significant negative effect on genetic diversity and evidence of isolation by river resistance was detected, suggesting that the landscape heterogeneity was preventing trout dispersal, both for native and exotic individuals. Moreover, several outlier SNPs were identified as potentially implicated in local adaptation to local hydroclimatic variables. Overall, this study suggests that O. chrysogater may require conservation planning given i) exotic introgression from O. mykiss locally threatening O. chrysogater genetic integrity, and ii) putative local adaptation but low genetic diversity and hence probably reduced evolutionary potential especially in a climate change context.

Preliminary Investigation of Genetic Variation within and between Cultivated and Natural Populations of Banksia coccinea and Banksia menziesii

1998 ◽  
Vol 46 (4) ◽  
pp. 547 ◽  
Author(s):  
M. A. Rieger ◽  
M. Sedgley
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Full Range ◽  
Preliminary Investigation ◽  
Natural Populations ◽  
South Australia ◽  
Randomly Amplified Polymorphic Dna ◽  
Analysis Of Molecular Variance ◽  
Molecular Variance ◽  
Cultivated Populations

The randomly amplified polymorphic DNA (RAPD) technique followed by analysis of molecular variance (AMOVA) was used to determine the level of variation within and between commercial plantations of Banksia coccinea R.Br. and B. menziesii R.Br. in South Australia and natural populations in Western Australia. For B. coccinea, the majority of variation was within populations (66.1%), while between all populations accounted for 20.8%. The variation between cultivated and natural populations was 13.2%. There was close clustering between the cultivated populations, which appeared to be most closely related to the inland natural populations. In contrast, the variation between cultivated and natural populations for B. menziesii was 0.4% with the majority of the variation within populations (93.2%) and 6.4% between all populations. The cultivated and natural populations formed a single cohesive cluster. These data indicate that the full range of natural genetic diversity of B. menziesii appears to occur in the cultivated plantations, but this was not the case for B. coccinea.

Livestock Effects on Genetic Variation of Creosote Bushes in Patagonian Rangelands

2018 ◽  
Vol 46 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Cintia P. Souto ◽  
Mariana Tadey
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Native Species ◽  
Environmental Changes ◽  
Natural Populations ◽  
Raw Material ◽  
Hierarchical Regression ◽  
Evolutionary Potential ◽  
Monte Desert ◽  
Larrea Divaricata

SummaryGenetic diversity is the raw material for species’ persistence over time, providing the potential to survive stochastic events, as well as climate and/or human-induced environmental changes. Biodiversity in dry rangelands is decreasing due to intensification of livestock production, but its effects on the genetic diversity of the consumed biota have seldom been assessed. We examined livestock effects on the genetic diversity of two dominant creosote species of the Patagonian Monte Desert, Larrea divaricata and Larrea cuneifolia. We deployed competing hierarchical regression models to assess the relationship between genetic variation within natural populations as a function of increasing stocking rates on ten arid rangelands. These species exhibit similar levels and patterns of genetic structure, with high levels of both inbreeding and divergence among locations. We found that increased stocking reduces genetic variation and increases genetic subdivision between populations. Our results indicate that grazing pressures are impoverishing the gene pool of these dominant native species of the Monte Desert, decreasing the evolutionary potential of the primary plant producers and increasing the desertification risk for a vulnerable habitat. We highlight the importance of considering livestock as a major driver of genetic losses in dry rangelands under overgrazing pressure, especially given current forecasts of climate change.

scholarly journals Development of Daphnia Magna SSR Markers and Genetic Diversity Analysis Based on RAD-Seq Technology

2021 ◽  
Author(s):  
Shengman Zhang ◽  
Yiran Xiong ◽  
Meng Tan ◽  
Siwei Chen ◽  
Zheng Han ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Daphnia Magna ◽  
Ssr Markers ◽  
Wild Population ◽  
Genetic Identity ◽  
Hunan Province ◽  
Shanxi Province ◽  
Information Index ◽  
Genetics Research

Abstract Daphnia magna belongs to the Cladocera order and plays an important role in the water ecosystem. With the intensification of water pollution, the wild population of D. magna has declined rapidly in recent years, and insufficient molecular markers have limited effective research and conservation of this species. In our research, 26 novel microsatellite (SSR) markers were developed in an artificially domesticated of D. magna and 12 wild population of D. magna using restriction site-associated DNA sequencing (RAD-seq). The results showed that the observed heterozygosity (Ho) and expected heterozygosity (He) ranged from 0.083 to 0.999 and 0.085 to 0.862, respectively. The PIC ranged from 0.368 to 0.805. These results indicate that the developed SSR marker is highly polymorphic. Nei’s genetic identity (H) ranged from 0.0926 to 0.3462, with a mean of 0.2233. Shannon’s Information index (I) ranged from 0.1333 to 0.4799, with an average of 0.3073; Shanxi province had the highest value and Hunan province had the lowest. Genetic distance and Nei’s genetic identity analysis, NJ tree diagram analysis, and PCoA analysis were conducted on populations of D. magna from different regions. The results show that the D. magna genetic relationship between Liaoning and Shanxi, Hunan and Anhui, and Beijing and Hainan is relatively close, while the genetic structure of D. magna in Guangdong, Jiangsu, and Sichuan is quite different from other sampling sites. An analysis of population genetic structure divided the test D. magna samples into two major groups. These results indicate that the genetic diversity of D. magna is rich, and the genetic structure of D. magna differs considerably in different regions. These research results and the newly developed polymorphic SSR markers for D. magna are of great significance in terms of the genetic breeding of D. magna, identification of wild and artificially domesticated population and conservation genetics research.

Already at the bottom? Demographic declines are unlikely further to undermine genetic diversity of a large Arctic ungulate: muskox, Ovibos moschatus (Artiodactyla: Bovidae)

2019 ◽  
Vol 129 (2) ◽  
pp. 459-469
Author(s):  
Erin Prewer ◽  
Susan Kutz ◽  
Lisa Marie Leclerc ◽  
Christopher J Kyle
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Allelic Richness ◽  
Evolutionary Potential ◽  
Ovibos Moschatus ◽  
Low Genetic Diversity ◽  
Expected Heterozygosity ◽  
Large Populations ◽  
Victoria Island ◽  
Demographic Patterns

Abstract Low genetic diversity is associated with low fitness and evolutionary potential, yet the demographic and life-history traits of some species contribute to low genetic diversity, without empirical evidence of negative impacts on fitness. Modelling past and future trajectories of genetic diversity under different demographic scenarios can provide insight into how genetic variation might impact population fitness. The muskox is an Arctic species that has undergone multiple population bottlenecks and, although populations have rebounded repeatedly, two large populations have recently declined by > 50%. It is unclear how these demographic patterns influence muskox genetic diversity and fitness. We compared the genetic diversity of Canadian muskox populations undergoing opposing population trends. Genotyping 84 mainland and 244 Victoria Island individuals at ten microsatellite loci revealed low genetic variation (Victoria Island, mean allelic richness 1.66, expected heterozygosity 0.16; mainland, mean allelic richness 2.58, expected heterozygosity 0.41), with no evidence of further reductions in diversity subsequent to recent demographic declines. Bayesian modelling showed that a 1900s bottleneck contributed to the lack of diversity in contemporary populations, and forward-in-time simulations suggested little effect on genetic diversity over the next 100 years. Muskoxen might have reached a genetic diversity minimum, and additional research will be needed to determine their capacity to adapt to rapid changes in selective pressures in a rapidly changing Arctic.

scholarly journals Changing environments and genetic variation: natural variation in inbreeding does not compromise short-term physiological responses

2019 ◽  
Vol 286 (1915) ◽  
pp. 20192109 ◽  
Author(s):  
James Buckley ◽  
Rónán Daly ◽  
Christina A. Cobbold ◽  
Karl Burgess ◽  
Barbara K. Mable
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Physiological Responses ◽  
Flowering Phenology ◽  
Mating Strategies ◽  
Relative Fitness ◽  
Evolutionary Potential ◽  
Short Term ◽  
Arabidopsis Lyrata ◽  
Physiological Capacity

Selfing plant lineages are surprisingly widespread and successful in a broad range of environments, despite showing reduced genetic diversity, which is predicted to reduce their long-term evolutionary potential. However, appropriate short-term plastic responses to new environmental conditions might not require high levels of standing genetic variation. In this study, we tested whether mating system variation among populations, and associated changes in genetic variability, affected short-term responses to environmental challenges. We compared relative fitness and metabolome profiles of naturally outbreeding (genetically diverse) and inbreeding (genetically depauperate) populations of a perennial plant, Arabidopsis lyrata , under constant growth chamber conditions and an outdoor common garden environment outside its native range. We found no effect of inbreeding on survival, flowering phenology or short-term physiological responses. Specifically, naturally occurring inbreeding had no significant effects on the plasticity of metabolome profiles, using either multivariate approaches or analysis of variation in individual metabolites, with inbreeding populations showing similar physiological responses to outbreeding populations over time in both growing environments. We conclude that low genetic diversity in naturally inbred populations may not always compromise fitness or short-term physiological capacity to respond to environmental change, which could help to explain the global success of selfing mating strategies.

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