scholarly journals Genetic variability of populations of the white-eared opossum, Didelphis albiventris Lund 1840 (Didelphimorphia; Didelphidae) in Brazil

2019 ◽  
Vol 79 (4) ◽  
pp. 594-602
Author(s):  
D. C. Nascimento ◽  
B. A. T. P. Campos ◽  
E. C. Fraga ◽  
M. C. Barros
Keyword(s):  
Gene Flow ◽  
Genetic Variability ◽  
Atlantic Forest ◽  
Population Analysis ◽  
Population Level ◽  
Haplotype Network ◽  
Mantel Test ◽  
Ancestral Polymorphism ◽  
Central Brazil ◽  
Didelphis Albiventris

Abstract Didelphis albiventris are found throughout Northeast and Central Brazil to central-southern Uruguay and it was subject of few studies in a population level. Given this, the present study investigated the genetic variability of the species using the mitochondrial molecular marker cytochrome oxidase c subunit I. We analyzed samples from the different biomes within three Brazilian regions: Northeast (Caatinga , Cerrado, and Atlantic Forest), Southeast (Cerrado , Atlantic Forest, Cerrado/Atlantic Forest, and Cerrado/Caatinga ecotones) and South (Pampa and Atlantic Forest). Software BAPs retrieved five distinct demes: dm 1, dm 2, and dm 5 that occurs in South, Northeast and Southeast regions respectively and the dm 3 and dm 4 are wide distributed in Northeast and Southeast. Population analysis performed with AMOVA, haplotype network and Mantel test estimated the veracity of the demes. The FST shows structuring for the five demes, with dm 1 (South region) isolated from the others, however the other analysis showed the Northeast/Southeast demes (dm 2-5) united, diagnosing gene flow between them, mainly at the transitional zones, in areas as far away as areas with similar latitude interval (Southeast vs South) that was not detected gene flow. In the haplotype network, the mutational steps was conclusive in split dm1 from dm 2-5 with 15 mutational steps and the Mantel test was moderated, which is explained by genetic similarity despite the great geographic distances (Northeast/Southeast). Thus, our analysis recognized two different lineages (South and Northeast/Southeast) and indicate that the biomes were not decisive in their isolation. The sharing of demes at the transitional zones and in areas with high latitudinal intervals reflects a recent ancestral polymorphism for D. albiventris. The plasticity in the occupation of the space by this species contributes in its wide dispersion capability, that is, geographical distribution. Our results revealed important implications for the management of D. albiventris in these transitional zones areas where demes were shared.

scholarly journals Isozyme and RAPD studies in Prosopis glandulosa and P. Velutina (Leguminosae, Mimosoideae)

2000 ◽  
Vol 23 (3) ◽  
pp. 639-648 ◽  
Author(s):  
Cecilia Bessega ◽  
Beatriz O. Saidman ◽  
Juan C. Vilardi
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Genetic Variability ◽  
Genetic Differentiation ◽  
Rapd Markers ◽  
Random Amplified Polymorphic Dna ◽  
Mantel Test ◽  
Prosopis Glandulosa ◽  
Geographical Distance ◽  
Taxonomic Studies

Allozyme and random amplified polymorphic DNA (RAPD) techniques have been compared for their usefulness for genetic and taxonomic studies in Prosopis glandulosa and P. velutina populations. Isozymes and RAPDs yielded similarly high estimates of genetic variability. Genetic structure and differentiation were analyzed through non-hierarchical Wright's F DT. For all populations considered, both markers produced low gene flow (Nm < 1) estimates. When only P. glandulosa populations were analyzed, isozyme data yielded higher gene flow estimates (Nm > 1), in agreement with that expected for conspecific populations. However, in RAPD data the expected reduction in F DT and the increase in Nm were not observed. Correlation between F DT and geographical distance matrices (Mantel test) for all populations was significant (P = 0.02) when based on isozymes, but not so (P = 0.33) when based on RAPDs. No significant associations among genetic and geographical or climatic variables were observed. Two isoenzyme systems (GOT and PRX) enabled us to distinguish between P. glandulosa and P. velutina, but no diagnostic band for recognition of populations or species studied here were detected by RAPD. However, RAPD markers showed higher values for genetic differentiation among conspecific populations of P. glandulosa and a lower coefficient of variation than those obtained from isozymes.

scholarly journals Genetic variability of Conopophaga lineata (Conopophagidae) (Wied-Neuwied, 1831) in Atlantic Forest fragments

2007 ◽  
Vol 67 (4 suppl) ◽  
pp. 859-865 ◽  
Author(s):  
GPM. Dantas ◽  
FR. Santos ◽  
MA. Marini
Keyword(s):  
Genetic Variability ◽  
Forest Fragmentation ◽  
Atlantic Forest ◽  
Geographic Distance ◽  
Great Part ◽  
Mantel Test ◽  
Conservation Strategies ◽  
Forest Fragments ◽  
Genetic Population ◽  
Bird Populations

Forest fragmentation affects bird populations in many ways, modifying the composition of communities and favouring open country species. The Atlantic Forest is considered one of the most important biomes in the world, due to its great biodiversity, accelerated rates of deforestation, and high endemism. Despite these characteristics, few studies have evaluated the effects of forest fragmentation in the genetic structure of Atlantic forest bird populations. So, this study aims to verify the effects of forest fragmentation in the genetic population structure of Conopophaga lineata, through RAPD markers. To achieve this goal, 89 C. lineata individuals were captured in nine Atlantic Forest fragments in Minas Gerais State. The RAPD data indicate that forest fragmentation has not affected the genetic variation of C. lineata populations (Mann-Whitney U = 3.50; p = 0.11). Great part of the genetic variability of this species is found within populations and it was not observed a correlation between genetic and geographic distance (Mantel test t = 0.6250; p = 073). UPGMA analyses did not show defined clades and all branches showed low statistical support. The low population differentiation observed in this species can be due to a high gene flow among populations or a recent fragmentation. Thus, the current diversity status of C. lineata populations indicates that this species is not significantly affected by fragmentation. However, more genetic studies are essential to improve conservation strategies of Brazilian Atlantic Forest birds.

scholarly journals Phylogenetic Relationships among Populations of the Vineyard Snail Cernuella virgata (Da Costa, 1778)

ISRN Zoology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Jasna Puizina ◽  
Sanja Puljas ◽  
Željana Fredotović ◽  
Ivica Šamanić ◽  
Grgur Pleslić
Keyword(s):  
Genetic Variability ◽  
16S Rdna ◽  
Phylogenetic Relationships ◽  
Western Europe ◽  
Population Analysis ◽  
Shell Growth ◽  
Shell Height ◽  
Haplotype Network ◽  
Coi Gene ◽  
Island Population

Cernuella virgata (Da Costa, 1778) (Mollusca: Hygromiidae), commonly known as the “vineyard snail,” is endemic species in Mediterranean and Western Europe including the British Isles, but in the Eastern USA and Australia it represents an introduced invasive species. The present work examines the genetic variability and phylogenetic relationships among the four populations of this land snail sampled along the east Adriatic region of Croatia using mitochondrial markers (partial 16S rDNA and COI gene) in addition to traditional methods of shell’s shape analysis. All the three molecular-phylogenetic approaches (median joining haplotype network analysis and Bayesian analysis, as well as maximum likelihood analysis) revealed two-three major subnetworks for both 16S rDNA and COI, with a clear distinction between south Adriatic haplotypes (Pisak) and north Adriatic haplotypes (Krk and Cres). The population from Karlobag was comprised of both north and south haplotypes, thus representing a putative contact zone between these two groups. The morphometric analysis showed that individuals from Cres island population were statistically significantly wider and higher than individuals from Pisak population. Analysis of the SW/SH ratio and the relationship between shell width and shell height showed no differences in shell growth between the two examined populations, indicating equal shell growth and shape, which gives the possibility that differences in size of individuals between those two populations could be influenced by biotic (physiological) or abiotic (environmental) factors. This study represents the first analysis of genetic variability and relatedness among native populations of C. virgata.

scholarly journals Fine-Scale Genetic Diversity of the Brazilian Pantaneiro Horse Breed Adapted To Flooded Regions

2021 ◽  
Author(s):  
Marcelo Bchara Nogueira ◽  
Concepta M Pimentel ◽  
Danielle Assis de Faria ◽  
Sandra Aparecida Oliveria Santos ◽  
Patrícia Ianella ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Variability ◽  
Genetic Distance ◽  
Animal Species ◽  
Principal Component ◽  
Mantel Test ◽  
Sampling Location ◽  
Sampling Strategies ◽  
The Impact

Abstract Among the animal species first introduced in Brazil during the country's discovery, horses (Equus caballus) stand out because of their evolutionary history and relationship with humans. Among the Brazilian horse breeds, the Pantaneiro draws attention due to its adaptative traits. Blood samples of 116 Pantaneiro horses were divided into six populations based on their sampling location, aiming to identify the existence of genetic structure and quantify genetic diversity within and between them. Populations were compared to elucidate genetic variability and differentiation better and assess the impact of Pantanal's natural geographic barriers on gene flow between populations. Data from the GGP Equine BeadChip (Geneseek-Neogen, 65.157 SNPs) was used to assess basic diversity parameters, genetic distance (FST), Principal Component Analysis (PCA) and population structure (ADMIXTURE) for the sampled animals. Mantel Test was also performed to investigate the correlation between the populations' genetic and geographic distances. Results showed high genetic variability in all populations, with elevated levels of admixture in their structure. High levels of admixture make it challenging to establish a racial pattern and, consequently, populations within the breed, being that only one of the populations differentiated itself from the others. No significant correlations between genetic and geographic distances were observed, indicating that environmental barriers did not hinder gene flow between populations. and neither farmers selection practices might have change breed genetic composition signficantly Low genetic distance and similar heterozygosity values were observed among populations, suggesting strong genetic proximity and low differentiation. Thereby, the Pantaneiro breed does not exhibit genetic subpopulations and could be considered, for conservation purposes, a single big population in the Panatnal region. This study will support sampling strategies for National genebank.

Systematics and evolution of Lentibulariaceae: III. Utricularia

2018 ◽  
Author(s):  
Richard W. Jobson ◽  
Paulo C. Baleeiro ◽  
Cástor Guisande
Keyword(s):  
Gene Flow ◽  
Species Diversity ◽  
Population Level ◽  
Oceanic Islands ◽  
Vulnerable Species ◽  
Phylogenetic Studies ◽  
Molecular Phylogenetic

Utricularia is a morphologically and ecologically diverse genus currently comprising more than 230 species divided into three subgenera—Polypompholyx, Utricularia, and Bivalvaria—and 35 sections. The genus is distributed worldwide except on the poles and most oceanic islands. The Neotropics has the highest species diversity, followed by Australia. Compared to its sister genera, Utricularia has undergone greater rates of speciation, which are linked to its extreme morphological flexibility that has resulted in the evolution of habitat-specific forms: terrestrial, rheophytic, aquatic, lithophytic, and epiphytic. Molecular phylogenetic studies have resolved relationships for 44% of the species across 80% of the sections. Scant data are available for phylogeography or population-level processes such as gene flow, hybridization, or pollination. Because nearly 90% of the species are endemics, data are urgently needed to determine how to protect vulnerable species and their habitats.

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 Divergent sorting of a balanced ancestral polymorphism underlies the establishment of gene-flow barriers in Capsella

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Adrien Sicard ◽  
Christian Kappel ◽  
Emily B. Josephs ◽  
Young Wha Lee ◽  
Cindy Marona ◽  
...  
Keyword(s):  
Gene Flow ◽  
Ancestral Polymorphism

scholarly journals Genetic structure and gene flow of Eugenia dysenterica natural populations

2005 ◽  
Vol 40 (10) ◽  
pp. 975-980 ◽  
Author(s):  
Maria Imaculada Zucchi ◽  
José Baldin Pinheiro ◽  
Lázaro José Chaves ◽  
Alexandre Siqueira Guedes Coelho ◽  
Mansuêmia Alves Couto ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Variability ◽  
Pearson Correlation ◽  
Natural Populations ◽  
Similarity Index ◽  
Genetic Distances ◽  
Strong Positive Correlation ◽  
Randomly Amplified Polymorphic Dna ◽  
Jaccard Similarity ◽  
Eugenia Dysenterica

This study was carried out to assess the genetic variability of ten "cagaita" tree (Eugenia dysenterica) populations in Southeastern Goiás. Fifty-four randomly amplified polymorphic DNA (RAPD) loci were used to characterize the population genetic variability, using the analysis of molecular variance (AMOVA). A phiST value of 0.2703 was obtained, showing that 27.03% and 72.97% of the genetic variability is present among and within populations, respectively. The Pearson correlation coefficient (r) among the genetic distances matrix (1 - Jaccard similarity index) and the geographic distances were estimated, and a strong positive correlation was detected. Results suggest that these populations are differentiating through a stochastic process, with restricted and geographic distribution dependent gene flow.

scholarly journals Genetic structure and historical and contemporary gene flow of Astyanaxmexicanus in the Gulf of Mexico slope: a microsatellite-based analysis

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10784
Author(s):  
Rodolfo Pérez-Rodríguez ◽  
Sarai Esquivel-Bobadilla ◽  
Adonaji Madeleine Orozco-Ruíz ◽  
José Luis Olivas-Hernández ◽  
Francisco Javier García-De León
Keyword(s):  
Gene Flow ◽  
Gulf Of Mexico ◽  
Microsatellite Loci ◽  
Evolutionary History ◽  
Population Analysis ◽  
Morphological Variability ◽  
High Capacity ◽  
Genetic Population ◽  
Contemporary Gene Flow ◽  
Taxonomic Uncertainty

Background Astyanax mexicanus from the river basins of the Gulf of Mexico slope are small freshwater fish that usually live in large groups in different freshwater environments. The group is considered successful due to its high capacity for dispersal and adaptation to different habitats, and the species present high morphological variability throughout their distribution in Mexico. This has produced the most extreme morphotype of the group; the hypogeous or troglobite, which has no eyes or coloration, and is probably the cause of taxonomic uncertainty in the recognition of species across the entire range. Most studies of A. mexicanus have mainly focused on cave individuals, as well as their adjacent surface locations, providing an incomplete evolutionary history, particularly in terms of factors related to dispersal and the potential corridors used, barriers to gene flow, and distribution of genetic variability. The aim of the present study is to determine the population structure and the degree and direction of genetic flow in this complex taxonomic group, incorporating geographic locations not previously included in analyses using microsatellite loci. Our aim is to contribute to the knowledge of the intricate evolutionary history of A. mexicanus throughout most of its range. Methods The present study included a set of several cave and surface locations of A. mexicanus, which have been widely sampled along the Gulf of Mexico slope, in a genetic population analysis using 10 microsatellite loci. Results Ten genetic populations or lineages were identified. In these populations, gene flow was recorded at two time periods. Historical gene flow, both inter and intra-basin, was observed among surface populations, from surface to cave populations, and among cave populations, whereas recording of contemporary gene flow was limited to intra-basin exchanges and observed among surface populations, surface to cave populations, and cave populations.

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