scholarly journals Influence of historical and human factors on genetic structure and diversity patterns in peripheral populations: implications for the conservation of Moroccan trout

2020 ◽  
Author(s):  
S Perea ◽  
M Al Amouri ◽  
EG Gonzalez ◽  
L Alcaraz ◽  
A Yahyaoui ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Brown Trout ◽  
Distribution Range ◽  
Peripheral Populations ◽  
List Type ◽  
Genetic Structuring ◽  
Evolutionary Patterns ◽  
Genetic Structure And Diversity ◽  
The Impact

AbstractThe brown trout s.l. has been the focus of numerous phylogeographic and conservation studies due to its socioeconomic importance, its marked genetic and phenotypic differentiation and its broad distribution range. Especially interesting evolutionary patterns are observed for populations occupying peripheral areas of a distribution range, such as in the case of the highly isolated trout populations in Morocco.Continuous stocking programs may conceal natural genetic patterns, making it challenging to discern evolutionary patterns. In Morocco, trout stocking programs have been implemented to increase the genetic diversity of native populations by pooling fish of different origins in the Ras el Ma hatchery (Azrou region) and then stocking them in the different basins. In this study, phylogenetic and phylogeographic patterns, as well as genetic structure and diversity, of Moroccan trout populations were analyzed to evaluate the impact of continuous fish stocking on evolutionary processes in order to better distinguish between natural and human-mediated patterns.Two mitochondrial and nine microsatellite markers were analyzed for all populations along the entire distribution range of brown trout in Morocco. Phylogenetic and phylogeographic analyses rendered two highly divergent evolutionary lineages, one comprising populations in the Drâa Basin and a second grouping the remaining Moroccan populations. Divergence of the Drâa lineage occurred during the Upper Pliocene, whilst differentiation within the second lineage coincided with the onset of the Pleistocene.Genetic structuring among populations was evident. Nevertheless, populations exhibiting higher levels of genetic diversity were those affected by human-mediated processes, making it difficult to associate this diversity with natural processes. In fact, highly geographically isolated, not stocked populations showed the lowest values of genetic diversity. Although stocking management may increase the genetic diversity of these populations, it could also lead to the loss of local adaptive genotypes. Hence, current trout conservation programs should be revised.

scholarly journals High levels of genetic diversity and an absence of genetic structure among breeding populations of the endangered Rufous-backed Bunting in Inner Mongolia, China: implications for conservation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shi Li ◽  
Dan Li ◽  
Lishi Zhang ◽  
Weiping Shang ◽  
Bo Qin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mitochondrial Dna ◽  
Genetic Structure ◽  
Endangered Species ◽  
Habitat Loss ◽  
Inner Mongolia ◽  
Avian Species ◽  
Genetic Structuring ◽  
Breeding Populations ◽  
The Impact

Abstract Background The Rufous-backed Bunting, Emberiza jankowskii, is an endangered species that is primarily distributed in Inner Mongolia, China. The main threats to the continued persistence of this species are habitat loss and degradation. However, the impact of population loss on genetic diversity remains unclear. To support future conservation and management efforts, we assessed the genetic diversity and population structure of E. jankowskii using mitochondrial DNA and microsatellites. Methods Blood samples were collected from 7‒8-day-old nestlings in Inner Mongolia, China between May and August of 2012 and 2013. Mitochondrial DNA sequences and microsatellite markers were used to assess the genetic diversity, genetic structure and inbreeding of E. jankowskii. The results of genetic diversity and inbreeding were compared to other avian species. Results We found an unexpectedly high level of genetic diversity in terms of mitochondrial DNA and microsatellite compared to other avian species. However, there were high levels of gene flow and minimal genetic structuring, among the fragmented breeding populations of E. jankowskii in Inner Mongolia. These findings suggest that E. jankowskii in Inner Mongolia is a metapopulation. Despite the high genetic diversity of E. jankowskii, local populations in each small patch remain at risk of extinction due to habitat loss. In addition, the E. jankowskii population has a high risk of inbreeding. Conclusions To minimize further loss of genetic diversity of this endangered species, we suggest that the E. jankowskii in Inner Mongolia should be considered as a protected species for management purposes. Conservation efforts should concentrate on E. jankowskii habitat management. This may be most effectively achieved by protecting the current breeding habitats and prohibiting over-grazing.

scholarly journals Spatio-temporal processes drive fine-scale genetic structure in an otherwise panmictic seabird population

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lucy J. H. Garrett ◽  
Julia P. Myatt ◽  
Jon P. Sadler ◽  
Deborah A. Dawson ◽  
Helen Hipperson ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Gene Pools ◽  
Fine Scale ◽  
Island Populations ◽  
Individual Fitness ◽  
Animal Populations ◽  
Spatio Temporal ◽  
Genetic Structure And Diversity ◽  
The Impact

AbstractWhen and where animals breed can shape the genetic structure and diversity of animal populations. The importance of drivers of genetic diversity is amplified in island populations that tend to have more delineated gene pools compared to continental populations. Studies of relatedness as a function of the spatial distribution of individuals have demonstrated the importance of spatial organisation for individual fitness with outcomes that are conditional on the overall genetic diversity of the population. However, few studies have investigated the impact of breeding timing on genetic structure. We characterise the fine-scale genetic structure of a geographically-isolated population of seabirds. Microsatellite markers provide evidence for largely transient within-breeding season temporal processes and limited spatial processes, affecting genetic structure in an otherwise panmictic population of sooty terns Onychoprion fuscatus. Earliest breeders had significantly different genetic structure from the latest breeders. Limited evidence was found for localised spatial structure, with a small number of individuals being more related to their nearest neighbours than the rest of the population. Therefore, population genetic structure is shaped by heterogeneities in collective movement in time and to a lesser extent space, that result in low levels of spatio-temporal genetic structure and the maintenance of genetic diversity.

scholarly journals Impact of cyclones on hard coral and metapopulation structure, connectivity and genetic diversity of coral reef fish

Coral Reefs ◽  
2021 ◽  
Author(s):  
Gabriele Gerlach ◽  
Philipp Kraemer ◽  
Peggy Weist ◽  
Laura Eickelmann ◽  
Michael J. Kingsford
Keyword(s):  
Genetic Diversity ◽  
Coral Reef ◽  
Genetic Structure ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Population Genetic Study ◽  
Hard Coral ◽  
Great Loss ◽  
Metapopulation Structure ◽  
The Impact

AbstractCyclones have one of the greatest effects on the biodiversity of coral reefs and the associated species. But it is unknown how stochastic alterations in habitat structure influence metapopulation structure, connectivity and genetic diversity. From 1993 to 2018, the reefs of the Capricorn Bunker Reef group in the southern part of the Great Barrier Reef were impacted by three tropical cyclones including cyclone Hamish (2009, category 5). This resulted in substantial loss of live habitat-forming coral and coral reef fish communities. Within 6–8 years after cyclones had devastated, live hard corals recovered by 50–60%. We show the relationship between hard coral cover and the abundance of the neon damselfish (Pomacentrus coelestis), the first fish colonizing destroyed reefs. We present the first long-term (2008–2015 years corresponding to 16–24 generations of P. coelestis) population genetic study to understand the impact of cyclones on the meta-population structure, connectivity and genetic diversity of the neon damselfish. After the cyclone, we observed the largest change in the genetic structure at reef populations compared to other years. Simultaneously, allelic richness of genetic microsatellite markers dropped indicating a great loss of genetic diversity, which increased again in subsequent years. Over years, metapopulation dynamics were characterized by high connectivity among fish populations associated with the Capricorn Bunker reefs (2200 km2); however, despite high exchange, genetic patchiness was observed with annual strong genetic divergence between populations among reefs. Some broad similarities in the genetic structure in 2015 could be explained by dispersal from a source reef and the related expansion of local populations. This study has shown that alternating cyclone-driven changes and subsequent recovery phases of coral habitat can greatly influence patterns of reef fish connectivity. The frequency of disturbances determines abundance of fish and genetic diversity within species.

scholarly journals Intraspecific divergences and phylogeography of Panzerina lanata (Lamiaceae) in Northwest China

2018 ◽  
Author(s):  
Yanfen Zhao ◽  
Hongxiang Zhang ◽  
Borong Pan ◽  
Mingli Zhang
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Genetic ◽  
Divergence Time ◽  
Northwest China ◽  
Northwestern China ◽  
Intraspecific Diversity ◽  
Early Pleistocene ◽  
Helan Mountains ◽  
The Impact

Climactic fluctuations during the Quaternary played a crucial role in genetic diversity and population genetic structure of many plant species in northwestern China. In order to understand the impact of climate change on herbaceous plants, we studied Panzerina lanata (Lamiaceae), a widely distributed species. Two chloroplast DNA intergenic spacers (trnH-psbA and rpoB-trnC) were used to sequence 269 individuals from 27 populations and seven haplotypes were identified. Genetic structure and demographic characteristics were estimated using AMOVA, neutrality tests, and mismatch distribution analyses. The divergence times between the seven haplotypes were estimated using Beast. Our results revealed high levels of total genetic diversity (HT = 0.673±0.0869) and low levels of average within-population genetic diversity (HS = 0.033±0.0214). The analysis of molecular variance indicated major genetic differentiation among the three groups: northern, central, and eastern group. The species distribution modeling and demographic analysis indicated that P. lanata has not experience a recent range expansion. The divergence time within P. lanata occurred between the early Pleistocene and the late Pleistocene, which coincides with aridification and the expansion of the deserts in northwestern China that resulted in species diversification and habitat fragmentation. In addition, we speculate that the deserts and the Helan Mountains acted as effective geographic barriers that led to intraspecific diversity.

scholarly journals Spectrum of genetic diversity and networks of clonal organisms

2007 ◽  
Vol 4 (17) ◽  
pp. 1093-1102 ◽  
Author(s):  
Alejandro F Rozenfeld ◽  
Sophie Arnaud-Haond ◽  
Emilio Hernández-García ◽  
Víctor M Eguíluz ◽  
Manuel A Matías ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Genetics ◽  
Genetic Structure ◽  
Small World ◽  
Clonal Plants ◽  
Posidonia Oceanica ◽  
Genetic Distances ◽  
Wide Range ◽  
Clonal Organisms ◽  
Genetic Structure And Diversity

Clonal reproduction characterizes a wide range of species including clonal plants in terrestrial and aquatic ecosystems, and clonal microbes such as bacteria and parasitic protozoa, with a key role in human health and ecosystem processes. Clonal organisms present a particular challenge in population genetics because, in addition to the possible existence of replicates of the same genotype in a given sample, some of the hypotheses and concepts underlying classical population genetics models are irreconcilable with clonality. The genetic structure and diversity of clonal populations were examined using a combination of new tools to analyse microsatellite data in the marine angiosperm Posidonia oceanica . These tools were based on examination of the frequency distribution of the genetic distance among ramets, termed the spectrum of genetic diversity (GDS), and of networks built on the basis of pairwise genetic distances among genets. Clonal growth and outcrossing are apparently dominant processes, whereas selfing and somatic mutations appear to be marginal, and the contribution of immigration seems to play a small role in adding genetic diversity to populations. The properties and topology of networks based on genetic distances showed a ‘small-world’ topology, characterized by a high degree of connectivity among nodes, and a substantial amount of substructure, revealing organization in subfamilies of closely related individuals. The combination of GDS and network tools proposed here helped in dissecting the influence of various evolutionary processes in shaping the intra-population genetic structure of the clonal organism investigated; these therefore represent promising analytical tools in population genetics.

scholarly journals Genetic structure and diversity of the endangered growling grass frog in a rapidly urbanizing region

2015 ◽  
Vol 2 (8) ◽  
pp. 140255 ◽  
Author(s):  
Claire C. Keely ◽  
Joshua M. Hale ◽  
Geoffrey W. Heard ◽  
Kirsten M. Parris ◽  
Joanna Sumner ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Dna Sequences ◽  
Nuclear Dna ◽  
Urban Expansion ◽  
Nuclear Gene ◽  
Management Approach ◽  
Natural Habitats ◽  
High Genetic Diversity ◽  
Genetic Structure And Diversity

Two pervasive and fundamental impacts of urbanization are the loss and fragmentation of natural habitats. From a genetic perspective, these impacts manifest as reduced genetic diversity and ultimately reduced genetic viability. The growling grass frog ( Litoria raniformis ) is listed as vulnerable to extinction in Australia, and endangered in the state of Victoria. Remaining populations of this species in and around the city of Melbourne are threatened by habitat loss, degradation and fragmentation due to urban expansion. We used mitochondrial DNA (mtDNA) and microsatellites to study the genetic structure and diversity of L. raniformis across Melbourne's urban fringe, and also screened four nuclear gene regions (POMC, RAG-1, Rhod and CRYBA1). The mtDNA and nuclear DNA sequences revealed low levels of genetic diversity throughout remnant populations of L. raniformis . However, one of the four regions studied, Cardinia, exhibited relatively high genetic diversity and several unique haplotypes, suggesting this region should be recognized as a separate Management Unit. We discuss the implications of these results for the conservation of L. raniformis in urbanizing landscapes, particularly the potential risks and benefits of translocation, which remains a contentious management approach for this species.

scholarly journals Genetic structure and diversity of a collection of Brassica rapa subsp. rapa L. revealed by simple sequence repeat markers

2011 ◽  
Vol 149 (5) ◽  
pp. 617-624 ◽  
Author(s):  
P. SOENGAS ◽  
M. E. CARTEA ◽  
M. FRANCISCO ◽  
M. LEMA ◽  
P. VELASCO
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Brassica Rapa ◽  
Genetic Relationships ◽  
Population Level ◽  
Research Centre ◽  
Breeding Programmes ◽  
Western Spain ◽  
Genetic Structure And Diversity ◽  
Simple Sequence

SUMMARYBrassica rapa subsp. rapa L. includes three different crops: turnips (roots), turnip greens (leaves) and turnip tops (inflorescences). A collection of B. rapa subsp. rapa from north-western Spain is currently kept at ‘Misión Biológica de Galicia’ (a research centre of the Consejo Superior de Investigaciones Científicas (CSIC), Spain). This collection has been characterized based on morphological and agronomical traits. A better understanding of the genetic diversity present in the collection is necessary in order to optimize its use and maintenance. The objectives of the present work were to assess the genetic diversity present in the B. rapa subsp. rapa collection, to establish genetic relationships among populations and to study the genetic structure of the collection. Eighty populations were analysed based on 18 simple sequence repeats (SSRs). Populations showed a broad range of genetic diversity, thus offering good potential for further genetic improvement. Most of the variability was found within the population level, probably due to high rates of allogamy, to migration and/or interchange of seed among local growers. Populations showed a low level of differentiation, grouping in just one cluster, and therefore they can be considered as samples of a highly variable metapopulation that can be used for B. rapa breeding programmes.

scholarly journals Genetic structure and diversity among individuals of Copaifera langsdorffii Desf. from Mato Grosso, Brazilian Amazon, using ISSR markers

2021 ◽  
Vol 10 (16) ◽  
pp. e187101623025
Author(s):  
Daniele Paula Maltezo ◽  
Julliane Dutra Medeiros ◽  
Ana Aparecida Bandini Rossi
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Genetic Variability ◽  
Polymorphic Information Content ◽  
Issr Markers ◽  
Group Method ◽  
Mato Grosso ◽  
Copaifera Langsdorffii ◽  
Genetic Structure And Diversity ◽  
Issr Primers

The Amazon is the largest tropical forest in the world and is home to around 20% of all the biodiversity on the planet, among the species present in the Amazon is Copaifera langsdorffii, exploited mainly for the extraction of oil-resin and wood, often in ways incorrect, which can cause the loss of genetic variability. The aim of this study was to evaluate the genetic structure and diversity among individuals of C. langsdorffii located in Mato Grosso, Brazil, using ISSR markers. We sampled leaves from 27 adult individuals of C. langsdorffii, whose total genomic DNA was extracted. A total of 12 ISSR primers were used for the molecular characterization of the individuals. A grouping analysis was performed using the unweighted pair group method, Bayesian analysis and characterized by the genetic diversity. The genetic diversity among and within the groups was demonstrated by the AMOVA. As a result, 106 fragments were amplified and 98.11% were polymorphic. The polymorphic information content of each primer ranged from 0.45 to 0.81.  The dendrogram showed the formation of 4 distinct groups. The greatest genetic variability is found within the groups and not between them. The percentage of polymorphism, genetic dissimilarity values and genetic diversity indexes indicate that there is high genetic variability among Copaifera langsdorffii individuals, suggesting that ISSR primers were efficient in detecting polymorphism in this species and that the individuals have potential for compose programs aimed at the preservation of the species and the ability to integrate germplasm banks.

scholarly journals Genetic variation and cryptic lineage diversity of the Nigerian red-headed rock agama Agama agama associate with eco-geographic zones

2019 ◽  
Vol 65 (6) ◽  
pp. 713-724 ◽  
Author(s):  
Lotanna M Nneji ◽  
Adeniyi C Adeola ◽  
Fang Yan ◽  
Agboola O Okeyoyin ◽  
Ojo C Oladipo ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Geographic Distance ◽  
Climatic Conditions ◽  
Population Divergence ◽  
Geographic Isolation ◽  
Genetic Structuring ◽  
Derived Savanna ◽  
Wide Range ◽  
Conservation Actions ◽  
The Impact

AbstractNigeria is an Afrotropical region with considerable ecological heterogeneity and levels of biotic endemism. Among its vertebrate fauna, reptiles have broad distributions, thus, they constitute a compelling system for assessing the impact of ecological variation and geographic isolation on species diversification. The red-headed rock agama, Agama agama, lives in a wide range of habitats and, thus, it may show genetic structuring and diversification. Herein, we tested the hypothesis that ecology affects its genetic structure and population divergence. Bayesian inference phylogenetic analysis of a mitochondrial DNA (mtDNA) gene recovered four well-supported matrilines with strong evidence of genetic structuring consistent with eco-geographic regions. Genetic differences among populations based on the mtDNA also correlated with geographic distance. The ecological niche model for the matrilines had a good fit and robust performance. Population divergence along the environmental axes was associated with climatic conditions, and temperature ranked highest among all environmental variables for forest specialists, while precipitation ranked highest for the forest/derived savanna, and savanna specialists. Our results cannot reject the hypothesis that niche conservatism promotes geographic isolation of the western populations of Nigerian A. agama. Thus, ecological gradients and geographic isolation impact the genetic structure and population divergence of the lizards. This species might be facing threats due to recent habitat fragmentation, especially in western Nigeria. Conservation actions appear necessary.

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