scholarly journals Alive and kicking, or, living on borrowed time? – Microsatellite diversity in natural populations of the endangered Ulmus minor Mill. sensu latissimo from Croatia

2016 ◽  
Vol 75 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Marko Zebec ◽  
Marilena Idžojtić ◽  
Zlatko Šatović ◽  
Igor Poljak ◽  
Zlatko Liber
Keyword(s):  
Genetic Diversity ◽  
Natural Populations ◽  
Genetic Bottleneck ◽  
Dutch Elm Disease ◽  
Significant Excess ◽  
Mediterranean Populations ◽  
Ulmus Minor ◽  
Study Results ◽  
The Impact ◽  
Microsatellite Diversity

AbstractThe main objective of this research was to assess the genetic diversity of 5 natural field elm populations in Croatia. The study results suggest that the observed populations are characterized by a satisfactory amount of heterozygosity, and that the impact of the Dutch elm disease on the amount of genetic diversity in the sampled populations is currently negligible. However, one population displayed a significant excess of heterozygosity, implying a genetic bottleneck. The existence of a very clear genetic differentiation between the continental and the Mediterranean populations of Ulmus minor in Croatia was noticed.

scholarly journals Coalescent Theory of Migration Network Motifs

2019 ◽  
Vol 36 (10) ◽  
pp. 2358-2374
Author(s):  
Nicolas Alcala ◽  
Amy Goldberg ◽  
Uma Ramakrishnan ◽  
Noah A Rosenberg
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Nucleotide Diversity ◽  
Natural Populations ◽  
Node Degree ◽  
Small Subset ◽  
Network Motifs ◽  
Coalescent Theory ◽  
Migration Networks ◽  
The Impact

Abstract Natural populations display a variety of spatial arrangements, each potentially with a distinctive impact on genetic diversity and genetic differentiation among subpopulations. Although the spatial arrangement of populations can lead to intricate migration networks, theoretical developments have focused mainly on a small subset of such networks, emphasizing the island-migration and stepping-stone models. In this study, we investigate all small network motifs: the set of all possible migration networks among populations subdivided into at most four subpopulations. For each motif, we use coalescent theory to derive expectations for three quantities that describe genetic variation: nucleotide diversity, FST, and half-time to equilibrium diversity. We describe the impact of network properties on these quantities, finding that motifs with a high mean node degree have the largest nucleotide diversity and the longest time to equilibrium, whereas motifs with low density have the largest FST. In addition, we show that the motifs whose pattern of variation is most strongly influenced by loss of a connection or a subpopulation are those that can be split easily into disconnected components. We illustrate our results using two example data sets—sky island birds of genus Sholicola and Indian tigers—identifying disturbance scenarios that produce the greatest reduction in genetic diversity; for tigers, we also compare the benefits of two assisted gene flow scenarios. Our results have consequences for understanding the effect of geography on genetic diversity, and they can assist in designing strategies to alter population migration networks toward maximizing genetic variation in the context of conservation of endangered species.

scholarly journals Reproductive Assurance Maintains Red-Flowered Plants of Lysimachia arvensis in Mediterranean Populations Despite Inbreeding Depression

2020 ◽  
Vol 11 ◽  
Author(s):  
Francisco J. Jiménez-López ◽  
Pedro L. Ortiz ◽  
María Talavera ◽  
Montserrat Arista
Keyword(s):  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Inbreeding Depression ◽  
Abiotic Factors ◽  
Natural Populations ◽  
Flower Color ◽  
Selfed Progeny ◽  
Mediterranean Populations ◽  
Mediterranean Areas ◽  
Flower Color Polymorphism

Flower color polymorphism, an infrequent but phylogenetically widespread condition in plants, is captivating because it can only be maintained under a few selective regimes but also because it can drive intra-morph assortative mating and promote speciation. Lysimachia arvensis is a polymorphic species with red or blue flowered morphs. In polymorphic populations, which are mostly Mediterranean, pollinators prefer blue-flowered plants to the red ones, and abiotic factors also favors blue-flowered plants. We hypothesize that the red morph is maintained in Mediterranean areas due to its selfing capacity. We assessed inbreeding depression in both color morphs in two Mediterranean populations and genetic diversity was studied via SSR microsatellites in 20 natural populations. Results showed that only 44–47% of selfed progeny of the red plants reached reproduction while about 72–91% of blue morph progeny did it. Between-morph genetic differentiation was high and the red morph had a lower genetic diversity and a higher inbreeding coefficient, mainly in the Mediterranean. Results suggest that selfing maintaining the red morph in Mediterranean areas despite its inbreeding depression. In addition, genetic differentiation between morphs suggests a low gene flow between them, suggesting reproductive isolation.

scholarly journals Coalescent theory of migration network motifs

2017 ◽  
Author(s):  
Nicolas Alcala ◽  
Amy Goldberg ◽  
Uma Ramakrishnan ◽  
Noah A. Rosenberg
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Nucleotide Diversity ◽  
Natural Populations ◽  
Node Degree ◽  
Small Subset ◽  
Network Motifs ◽  
Coalescent Theory ◽  
Migration Networks ◽  
The Impact

ABSTRACTNatural populations display a variety of spatial arrangements, each potentially with a distinctive impact on genetic diversity and genetic differentiation among subpopulations. Although the spatial arrangement of populations can lead to intricate migration networks, theoretical developments have focused mainly on a small subset of such networks, emphasizing the island-migration and stepping-stone models. In this study, we investigate all small network motifs: the set of all possible migration networks among populations subdivided into at most four subpopulations. For each motif, we use coalescent theory to derive expectations for three quantities that describe genetic variation: nucleotide diversity, FST, and half-time to equilibrium diversity. We describe the impact of network properties on these quantities, finding that motifs with a large mean node degree have the largest nucleotide diversity and the longest time to equilibrium, whereas motifs with small density have the largest FST. In addition, we show that the motifs whose pattern of variation is most strongly influenced by loss of a connection or a subpopulation are those that can be split easily into several disconnected components. We illustrate our results using two example datasets—sky island birds of genus Brachypteryx and Indian tigers—identifying disturbance scenarios that produce the greatest reduction in genetic diversity; for tigers, we also compare the benefits of two assisted gene flow scenarios. Our results have consequences for understanding the effect of geography on genetic diversity and for designing strategies to alter population migration networks to maximize genetic variation in the context of conservation of endangered species.

scholarly journals Genetic bottleneck and founder effect signatures in a captive population of common bottlenose dolphins Tursiops truncatus (Montagu 1821) in Mexico

2018 ◽  
Author(s):  
Monica Améndola-Pimenta ◽  
Miriam Camelo-Marrufo ◽  
Jesús Alejandro Zamora-Briseño ◽  
Ioreni Margarita Hernández-Velázquez ◽  
Roberto Zamora-Bustillos ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Microsatellite Markers ◽  
Founder Effect ◽  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Genetic Bottleneck ◽  
Quintana Roo ◽  
Captive Population ◽  
The Impact

Background. The captive cetacean industry is very profitable and popular worldwide, focusing mainly on leisure activities such as “Swim-with-dolphins” (SWD) programs. However, there is a concern for how captivity could affect the bottlenose dolphin Tursiops truncatus, which in nature is a highly social and widespread species. To date, there is little information regarding to the impact of restricted population size on their genetic structure and variability. Methods. The aim of this study was to estimate the genetic diversity of a confined population of T. truncatus, composed of wild-born (n=25) from Cuba, Quintana Roo and Tabasco, and captive-born (n=24) dolphins in southern Mexico, using the hypervariable portion of the mitochondrial DNA and ten nuclear microsatellite markers: TexVet3, TexVet5, TexVet7, D18, D22, Ttr19, Tur4_80, Tur4_105, Tur4_141 and GATA098. Results. Exclusive mtDNA haplotypes were found in at least one individual from each wild-born origin populations and in one captive-born individual; total mean haplotype and nucleotide diversities were 0.912 (±0.016) and 0.025 (±0.013) respectively. At microsatellite loci, low levels of genetic diversity were found with a mean number of alleles per locus of 4 (±2.36), and an average expected heterozygosity over all loci of 0.544 (±0.163). Measures of allelic richness and effective number of alleles were similar between captive-born and wild-born dolphins. No significant genetic structure was found with microsatellite markers, whereas the mtDNA data revealed a significant differentiation between wild-born organisms from Cuba and Quintana ROO. Discussion. Data analysis suggests the occurrence of a recent genetic bottleneck in the confined population probably because of a strong founder effect, given that only a small number of dolphins with a limited fraction of the total species genetic variation were selected at random to start this captive population. The results herein provide the first genetic baseline information on a captive bottlenose dolphin population in Mexico.

scholarly journals Genetic diversity, structure, and kinship analysis of Trachemys venusta venusta in Wildlife Management Units and wild populations in south Mexico. Implications for conservation and management

2020 ◽  
Author(s):  
Elsi B. Recino-Reyes ◽  
Julia M. Lesher-Gordillo ◽  
Salima Machkour-M’Rabet ◽  
Manuel I. Gallardo-Alvárez ◽  
Claudia E. Zenteno-Ruiz ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Natural Populations ◽  
Management Plan ◽  
Freshwater Turtle ◽  
Freshwater Turtles ◽  
Wild Populations ◽  
Genetic Management ◽  
Kinship Analysis ◽  
Management Units ◽  
The Impact

AbstractThe Meso-American slider turtle (Trachemys venusta) is a freshwater turtle endemic to Mexico and Central America. Due to the overexploitation of its natural populations, it is in the at risk category formulated by the Official Mexican Standard NOM-059-ECOL-2010. In the state of Tabasco, Management Units for the Conservation of Wildlife (UMA) were created to reduce the impact of overexploitation of freshwater turtles. However, no genetic management plan was considered. This study presents the level of genetic diversity of the founder individuals in order to develop a management plan which will optimize reproduction in the UMA. Genetic diversity was compared between captive (n = 45) and wild (n = 86) individuals using 14 microsatellite molecular markers. Level of genetic diversity could be considered as low (He < 0.6) for a species of turtle and suggests that a higher level of protection is required for this particular species. Furthermore, values were slightly higher for the captive group reflecting the mix of genetic sources (founding individuals from different localities) and demonstrating that the captive population is genetically representative of natural populations. The genetic structure analysis revealed a relationship between captive and wild populations, indicating the influence of the two principal river basins in this region on the population of freshwater turtles. Finally, according to the results obtained from the analysis conducted using Storm and ML-Relate programs, we recommend the use of 19 females and 13 males, generating a potential of 247 dyads with no relationship. These first results of genetic management in a Mexican UMA, demonstrate the importance of molecular approaches at the time of managing and conserving species in captivity.

scholarly journals Genetic analysis of Rhaponticum carthamoides (Asteraceae) during restoration of natural populations in the Altai Republic

2021 ◽  
Vol 38 ◽  
pp. 00064
Author(s):  
Irina Kuban ◽  
Elena Zhmud ◽  
Altynai Achimova ◽  
Natasha Williams ◽  
Olga Dorogina
Keyword(s):  
Genetic Diversity ◽  
Genetic Analysis ◽  
Natural Populations ◽  
Impact Factors ◽  
Economic Activities ◽  
Altai Republic ◽  
Remote Locations ◽  
Rhaponticum Carthamoides ◽  
The Impact ◽  
Two Populations

Rhaponticum carthamoides (Willd.) Iljin is a rare species for Altai Republic. It possesses medicinal and fodder properties and therefore is considered a valuable resource species. Populations of this species are regularly exposed to anthropogenic impact. The impact factors are harvesting of rhizomes and cattle grazing. We have carried out the restoration of two populations of this species. The seeds for restorative planting were collected from healthy plants in the same populations, at a distance of 10 km or less from the restoration site. The genetic analysis of DNA fragments showed a reliable similarity of genetic diversity in planted and naturally growing individuals in each of the studied populations. Comparison showed that plants in more remote locations, which are less accessible for tourism and economic activities, were characterized by higher genetic diversity.

scholarly journals Genetic bottleneck and founder effect signatures in a captive population of common bottlenose dolphins Tursiops truncatus (Montagu 1821) in Mexico

2018 ◽  
Author(s):  
Monica Améndola-Pimenta ◽  
Miriam Camelo-Marrufo ◽  
Jesús Alejandro Zamora-Briseño ◽  
Ioreni Margarita Hernández-Velázquez ◽  
Roberto Zamora-Bustillos ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Microsatellite Markers ◽  
Founder Effect ◽  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Genetic Bottleneck ◽  
Quintana Roo ◽  
Captive Population ◽  
The Impact

Background. The captive cetacean industry is very profitable and popular worldwide, focusing mainly on leisure activities such as “Swim-with-dolphins” (SWD) programs. However, there is a concern for how captivity could affect the bottlenose dolphin Tursiops truncatus, which in nature is a highly social and widespread species. To date, there is little information regarding to the impact of restricted population size on their genetic structure and variability. Methods. The aim of this study was to estimate the genetic diversity of a confined population of T. truncatus, composed of wild-born (n=25) from Cuba, Quintana Roo and Tabasco, and captive-born (n=24) dolphins in southern Mexico, using the hypervariable portion of the mitochondrial DNA and ten nuclear microsatellite markers: TexVet3, TexVet5, TexVet7, D18, D22, Ttr19, Tur4_80, Tur4_105, Tur4_141 and GATA098. Results. Exclusive mtDNA haplotypes were found in at least one individual from each wild-born origin populations and in one captive-born individual; total mean haplotype and nucleotide diversities were 0.912 (±0.016) and 0.025 (±0.013) respectively. At microsatellite loci, low levels of genetic diversity were found with a mean number of alleles per locus of 4 (±2.36), and an average expected heterozygosity over all loci of 0.544 (±0.163). Measures of allelic richness and effective number of alleles were similar between captive-born and wild-born dolphins. No significant genetic structure was found with microsatellite markers, whereas the mtDNA data revealed a significant differentiation between wild-born organisms from Cuba and Quintana ROO. Discussion. Data analysis suggests the occurrence of a recent genetic bottleneck in the confined population probably because of a strong founder effect, given that only a small number of dolphins with a limited fraction of the total species genetic variation were selected at random to start this captive population. The results herein provide the first genetic baseline information on a captive bottlenose dolphin population in Mexico.

Ecological genetics of the wind-pollinated, tetraploid, Allocasuarina emuina L. Johnson (Casuarinaceae) from southeast Queensland reveals montane refugia for coastal heath during the last interglacial

2012 ◽  
Vol 60 (8) ◽  
pp. 718 ◽  
Author(s):  
R. W. Lamont ◽  
R. L. Stokoe ◽  
A. Shapcott
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Population Genetic ◽  
Genetic Material ◽  
Natural Populations ◽  
Seed Viability ◽  
Ecological Genetics ◽  
Last Interglacial ◽  
Study Results ◽  
Southeast Queensland

The subtropical coastal heathlands of southeast Queensland contain many rare and threatened species and have undergone considerable habitat loss in recent years due to high levels of urbanisation. We used morphological and microsatellite markers to investigate the reproductive ecology, in relation to fire, and population genetic structure of the endangered shrub Allocasuarina emuina. Highly significant differences (P < 0.001) were detected among populations for all cone- and seed-related morphological traits, which revealed distinct northern and southern groups of populations, a pattern repeated in the genetic component of the study. Results also indicated that the reproductive viability of A. emuina is more related to fire interval than population size and confirmed that seed viability declines with time since fire. The highest level of genetic diversity for the species was observed in the population on Mt Emu (AE4A; HE = 0.688). Contrary to the expectations of population genetic theory, no relationship was found between the level of genetic variation and population size, density or degree of isolation, hinting that genetic diversity is being conserved as a result of polyploidy and apomixis. However, genetic signatures in the northern populations indicated that unidirectional dispersal of genetic material from the putatively refugial population on Mt Emu to the surrounding coastal plain has been occurring with recession of sea levels following the last interglacial. The findings of the study will aid in both the conservation of natural populations and translocations of A. emuina and have significant implications relating to the biogeographical history of a considerable number of co-occurring heathland taxa.

scholarly journals Mitochondrial Genome Evolution, Genetic Diversity, and Population Structure in British Water Voles (Arvicola amphibius)

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 138
Author(s):  
Corey Kirkland ◽  
Marta Farré
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Mitochondrial Genome ◽  
Captive Breeding ◽  
Natural Populations ◽  
Water Vole ◽  
Captive Population ◽  
Arvicola Amphibius ◽  
Relationship Of ◽  
The Impact

The European water vole (Arvicola amphibius) is a rodent within the subfamily Arvicolinae. In Britain, water voles have declined rapidly during the last century, making them a conservation priority. The relationship of Arvicola to other genera within Arvicolinae remains debated. Additionally, the impact that captive breeding programs in Britain are having on the genetic diversity of water voles is unknown. We use available mitochondrial genomes to construct the phylogeny of species within Arvicolinae, followed by sequencing the mitochondrial DNA control region of 17 individuals from a captive population of water voles in Britain to assess their genetic diversity and population structure. Our study first provides an updated phylogenetic tree of Arvicolinae using the mitochondrial genome of 31 species. Second, our results show considerable genetic diversity in the captive population of water voles, when compared with natural populations in Britain. We confirm the grouping of British water voles into two clades, with all captive individuals found in the English/Welsh clade. Moreover, captive water voles clustered closely with populations in the South East and East of England. The mitochondrial genome provides a useful marker to study the phylogenetics of this rodent clade and in addition, our study provides support for the breeding program at Wildwood Trust and provides a framework for future conservation genetics studies in this species.

Income Diversification and Bank Efficiency in Vietnam

2017 ◽  
pp. 52-67
Author(s):  
Sang Nguyen Minh
Keyword(s):  
Regression Model ◽  
Commercial Banks ◽  
Banking System ◽  
Operational Efficiency ◽  
Commercial Banking ◽  
Tobit Regression ◽  
Income Diversification ◽  
Positive Effects ◽  
Study Results ◽  
The Impact

This study uses the DEA (Data Envelopment Analysis) method to estimate the technical efficiency index of 34 Vietnamese commercial banks in the period 2007-2015, and then it analyzes the impact of income diversification on the operational efficiency of Vietnamese commercial banks through a censored regression model - the Tobit regression model. Research results indicate that income diversification has positive effects on the operational efficiency of Vietnamese commercial banks in the research period. Based on study results, in this research some recommendations forpolicy are given to enhance the operational efficiency of Vietnam’s commercial banking system.

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