scholarly journals Quantification of Outcrossing Events in Haploid Fungi Using Microsatellite Markers

2020 ◽  
Vol 6 (2) ◽  
pp. 48
Author(s):  
Dong-Hyeon Lee ◽  
Brenda D. Wingfield ◽  
Jolanda Roux ◽  
Michael J. Wingfield
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
High Frequency ◽  
Reproductive Strategies ◽  
Mating Strategies ◽  
Mating Types ◽  
Ceratocystis Fimbriata ◽  
Mating Type Switching ◽  
High Level

Species in genera of the fungal family Ceratocystidaceae are known to have different mating strategies, including heterothallism and homothallism. Of these, species of Ceratocystis, typified by the pathogen Ceratocystis fimbriata all undergo unidirectional mating-type switching. This implies that the pathogens possess the ability to self, but also to undergo sexual outcrossing between isolates of different mating types. In this study, we extended the recently developed microsatellite-based technique to determine the extent to which outcrossing occurs in ascospore masses of haploid fungi to two field collections of Ceratocystis albifundus. In this way, the role of reproductive strategies in shaping population structure and diversity could be better understood. Results showed that a high frequency of outcrossing occurs in isolates of the pathogen from both non-native and native areas. This explains the high level of genetic diversity previously observed in this population despite the fact that this pathogen has the ability to self.

scholarly journals Genetic Diversity in the mtDNA control region and population structure of Chrysichthys nigrodigitatus from selected Nigerian rivers: Implications for conservation and aquaculture

2016 ◽  
Vol 24 (2) ◽  
pp. 85-97 ◽  
Author(s):  
Sylvanus A. Nwafili ◽  
Tian-Xiang Gao
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Control Region ◽  
Haplotype Diversity ◽  
Population Expansion ◽  
Mitochondrial Control Region ◽  
Recent Population Expansion ◽  
Base Pair Fragment ◽  
Population Structures ◽  
High Level

Abstract The genetic diversity and population structure of Chrysichthys nigrodigitatus were evaluated using a 443 base pair fragment of the mitochondrial control region. Among the eight populations collected comprising 129 individuals, a total of 89 polymorphic sites defined 57 distinct haplotypes. The mean haplotype diversity and nucleotide diversity of the eight populations were 0.966±0.006 and 0.0359±0.004, respectively. Analysis of molecular variance showed significant genetic differentiation among the eight populations (FST =0.34; P < 0.01). The present results revealed that C. nigrodigitatus populations had a high level of genetic diversity and distinct population structures. We report the existence of two monophyletic matrilineal lineages with mean genetic distance of 10.5% between them. Non-significant negative Tajima’s D and Fu’s Fs for more than half the populations suggests that the wild populations of C. nigrodigitatus underwent a recent population expansion, although a weak one since the late Pleistocene.

scholarly journals POPULATION STRUCTURE OFDIPODOMYS INGENS(HETEROMYIDAE): THE ROLE OF SPATIAL HETEROGENEITY IN MAINTAINING GENETIC DIVERSITY

Evolution ◽  
1997 ◽  
Vol 51 (4) ◽  
pp. 1296-1310 ◽  
Author(s):  
Sara V. Good ◽  
Daniel F. Williams ◽  
Katherine Ralls ◽  
Robert C. Fleischer
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Spatial Heterogeneity

scholarly journals Genetic Diversity and Population Structure of Endangered Catfish Rita rita (Hamilton, 1822) Revealed by Heterologous DNA Microsatellite Markers

2021 ◽  
Vol 34 (2) ◽  
Author(s):  
MUHAMMAD FORHAD ALI ◽  
◽  
MD. RAFIQUL ISLAM SARDER ◽  
MOHAMMAD MATIUR RAHMAN ◽  
MD. FAZLUL AWAL MOLLAH ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Diversity ◽  
Polymorphic Information Content ◽  
Genetic Difference ◽  
Information Index ◽  
Hardy Weinberg Equilibrium ◽  
High Gene ◽  
High Level ◽  
Dna Microsatellite

Genetic information is essential for conservation and future aquaculture development of the endangered catfish Rita rita (Hamilton, 1822). Two hundred catfish, R. rita, 50 from four rivers, the Old Brahmaputra, Jamuna, Meghna and Kangsa were collected and analysed to evaluate the genetic diversity and population structure using five microsatellite primers (Cba06-KUL, Cba08-KUL, Cba09-KUL, Phy03-KUL and Phy07-KUL). Four of the five amplified loci were found polymorphic (P95) in all the populations and 46 alleles were recorded with 9 to 14 alleles per locus. Differences were observed in the total number of alleles ranging from 41 to 44, effective number of alleles from 29.96 to 37.46, observed heterozygosity from 0.57 to 0.76, Shannon’s information index from 2.09 to 2.30 and polymorphic information content from 0.84 to 0.88 among the four populations. Results exposed the highest levels of genetic diversity in the Meghna population while the lowest in the Kangsa population of R. rita. All the populations were significantly deviated (P < 0.001) from the Hardy-Weinberg equilibrium for all the loci. Nei’s genetic distance between populations ranged 0.007 to 0.017 with low overall genetic difference FST = 0.011 and high gene flow Nm = 24.333, indicating that R. rita populations were not subdivided. This study revealed a high level of gene diversity with deficiency in genetic heterogeneity in all the populations of R. rita, emphasising natural management, conservation and rehabilitation measures of this species.

scholarly journals Chloroplast microsatellites reveal genetic diversity and population structure in natural populations of Himalayan Cedar (Cedrus deodara (Roxb.) G. Don) in India

2020 ◽  
Vol 69 (1) ◽  
pp. 86-93
Author(s):  
H. S. Ginwal ◽  
Rajesh Sharma ◽  
Priti Chauhan ◽  
Kirti Chamling Rai ◽  
Santan Barthwal
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Natural Populations ◽  
Conservation Strategies ◽  
Restricted Gene Flow ◽  
Chloroplast Microsatellites ◽  
Timber Species ◽  
Western Himalayas ◽  
Cedrus Deodara ◽  
High Level

AbstractHimalayan cedar (Cedrus deodara) is one of the most important temperate timber species of Western Himalayas and is considered to be among the endangered conifer species in the region. Knowledge of genetic diversity and population structure will help guide gene conservation strategies for this species. Ten polymorphic chloroplast microsatellites (cpSSR) were used to study genetic diversity and population structure in twenty one natural populations of C. deodara throughout its entire distribution range in Western Himalayas. When alleles at each of the 10 loci were jointly analysed, 254 different haplotypes were identified among 1050 individuals. The cpSSRs indicate that C. deodara forests maintain a moderately high level of genetic diversity (mean h = 0.79 ). AMOVA analysis showed that most of the diversity in C. deodara occurs within populations. Bayesian analysis for population structure (BAPS) revealed spatial structuration of the variation (22 % of the total variation) and substructuring captured nineteen genetic clusters in the entire divisions of the populations. Most of the populations were clustered independently with minor admixtures. The distribution of genetic diversity and sub-structuring of C. deodara may be due to restricted gene flow due to geographic isolation, genetic drift, and natural selection. These findings indicated existence of genetically distinct and different high diversity and low diversity clusters, which are potential groups of populations that require attention for their conservation and management. The results are interpreted in context of future conservation plans for C. deodara.

scholarly journals Genetic Diversity and Population Structure Revealed by SSR Markers on Endemic Species Osmanthus serrulatus Rehder from Southwestern Sichuan Basin, China

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1365
Author(s):  
Lin Chen ◽  
Tingting Pan ◽  
Huirong Qian ◽  
Min Zhang ◽  
Guodong Yang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Ssr Markers ◽  
Sichuan Basin ◽  
Polymorphic Information Content ◽  
Population Decline ◽  
Natural Populations ◽  
Genetic Population ◽  
Endangered Status ◽  
High Level

Osmanthus serrulatus Rehder (Oleaceae) is an endemic spring-flowering species in China. It is narrowly distributed in the southwestern Sichuan Basin, and is facing the unprecedented threat of extinction due to problems associated with natural regeneration, habitat fragmentation and persistent and serious human interference. Here, the genetic diversity and population structure of 262 individuals from ten natural populations were analyzed using 18 microsatellites (SSR) markers. In total, 465 alleles were detected across 262 individuals, with a high polymorphic information content (PIC = 0.893). A high level of genetic diversity was inferred from the genetic diversity parameters (He = 0.694, I = 1.492 and PPL = 98.33%). AMOVA showed that a 21.55% genetic variation existed among populations and the mean pairwise Fst (0.215) indicated moderate genetic population differentiation. The ten populations were basically divided into three groups, including two obviously independent groups. Our results indicate that multiple factors were responsible for the complicated genetic relationship and endangered status of O. serrulatus. The concentrated distribution seems to be the key factor causing endangerment, and poor regeneration, human-induced habitat loss and fragmentation seem to be the primary factors in the population decline and further genetic diversity loss. These findings will assist in future conservation management and the scientific breeding of O. serrulatus.

Comparative assessment of SCoT and ISSR markers for analysis of genetic diversity and population structure in some Aegilops tauschii Coss. accessions

2021 ◽  
pp. 1-9
Author(s):  
Atefeh Nouri ◽  
Maryam Golabadi ◽  
Alireza Etminan ◽  
Abdolmajid Rezaei ◽  
Ali Ashraf Mehrabi
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Aegilops Tauschii ◽  
Inter Simple Sequence Repeat ◽  
Issr Markers ◽  
Start Codon ◽  
D Genome ◽  
Breeding Programmes ◽  
High Level ◽  
Effective Multiplex Ratio

Abstract Aegilops tauschii, the diploid progenitor of the wheat D-genome, is a valuable genetic resource for wheat breeders. In this study, we compared the efficiency of inter-simple sequence repeat (ISSR) (as an arbitrary technique) and start codon targeted (SCoT) (as a gene-targeting technique) markers in determining the genetic diversity and population structure of 90 accessions of Ae. tauschii. SCoT markers indicated the highest values for polymorphism information content, marker index and effective multiplex ratio compared to ISSR markers. The total genetic diversity (Ht) and genetic diversity within populations (Hs) parameters were comparably modest for the two marker systems. The results of the analysis of molecular variance showed that the genetic variation within populations was significantly higher than among them (ISSR: 92 versus 8%; SCoT: 88 versus 12%). Furthermore, SCoT markers discovered a high level of genetic differentiation among populations than ISSRs (0.19 versus 0.05), while the amount of gene flow detected by ISSR was higher than SCoT (2.13 versus 8.62). Cluster analysis and population structure of SCoT and ISSR data divided all investigated accessions into two and four main clusters, respectively. Our results revealed that SCoT and ISSR fingerprinting could be used to further molecular analysis in Ae. tauschii and other wild species. The high-genetic variability found in this study also indicates the valuable genetic potential present in the investigated Ae. tauschii germplasm, which could be utilized for future genetic analysis and linkage mapping in breeding programmes.

scholarly journals PSVIII-23 High-density SNP marker based genetic diversity and population structure study of reindeer populations

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 265-266
Author(s):  
Veronika R Kharzinova ◽  
Arsen V Dotsev ◽  
Anastasiya Solovieva ◽  
Klaus Wimmers ◽  
Henry Reyer ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Structure Study ◽  
Snp Markers ◽  
Negative Effects ◽  
Russian Science ◽  
Data Set ◽  
Northern Territories ◽  
High Level ◽  
Wild Reindeer

Abstract Wild reindeer populations form the basis of the traditional activities of indigenous peoples of the northern territories of Siberia, the main part of which is concentrated in two large regions: Taimyr and Northern Yakutia. Currently, there is a sharp decline in the number of wild reindeer, which leads to a loss of the genetic diversity necessary for survival in the changing habitat conditions. To infer the population structure and genome-wide diversity of wild reindeer, the Taymyr (TAI, n = 33) and Yakut populations including Tundra Leno-Olenek (LNO, n = 20), the Island (ISL, n = 6), the Sundrun (SUN, n = 6) and the Taiga (TGA, n = 5) were genotyped with the Illumina Bovine HD BeadChip. Data set consisting of 8801 polymorphic SNP markers was used to calculate population genetic parameters in PLINK 1.9, SplitsTree 4.14.6. software, R packages “diveRsity” and “StAMMP.” We detected the similar level of observed heterozygosity across the TAI, ISL, SUN and LNO: 0.187, 0.188, 0.184, and 0.189 respectively. Meanwhile, allelic richness was slightly higher in Taimyr population compared to the Yakut groups. The lowest level of genetic diversity was recorded in the Taiga reindeer (Ho=0.168; Ar = 1.476). All populations showed heterozygotes deficiency (uFIS 95%, CI &gt; 0) with higher uFIS values in TGA (0.079). MDS analysis revealed the high level of genetic similarity of TAI, ISL and LNO and placed SUN in close proximity to them. The first and the second MDS components (2.36% and 2.15% of the genetic variability) clearly divided the Taiga reindeer, the genetic apartness of which was also confirmed by the results of the Neighbour-Net tree analysis. Information obtained here, might be helpful for further effective use and maintenance of the reindeer populations as well as for overcoming the negative effects of decreasing their number. The study was supported by Russian Science Foundation within Pr. no. 16-16-10068.

scholarly journals Genetics of Host Protection against Helicobacter pylori Infections

2021 ◽  
Vol 22 (6) ◽  
pp. 3192 ◽  
Author(s):  
Rosanna Capparelli ◽  
Domenico Iannelli
Keyword(s):  
Genetic Diversity ◽  
Helicobacter Pylori ◽  
T Regulatory Cells ◽  
Protective Role ◽  
Disease Genes ◽  
Nucleotide Polymorphisms ◽  
High Genetic Diversity ◽  
Host Protection ◽  
High Level

This narrative review discusses the genetics of protection against Helicobacter pylori (Hp) infection. After a brief overview of the importance of studying infectious disease genes, we provide a detailed account of the properties of Hp, with a view to those relevant for our topic. Hp displays a very high level of genetic diversity, detectable even between single colonies from the same patient. The high genetic diversity of Hp can be evaded by stratifying patients according to the infecting Hp strain. This approach enhances the power and replication of the study. Scanning for single nucleotide polymorphisms is generally not successful since genes rarely work alone. We suggest selecting genes to study from among members of the same family, which are therefore inclined to cooperate. Further, extending the analysis to the metabolism would significantly enhance the power of the study. This combined approach displays the protective role of MyD88, TIRAP, and IL1RL1 against Hp infection. Finally, several studies in humans have demonstrated that the blood T cell levels are under the genetic control of the CD39+ T regulatory cells (TREGS).

scholarly journals Genetic variation and population structure of clonal Zingiber zerumbet at a fine geographic scale: a comparison with two closely related selfing and outcrossing Zingiber species

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rong Huang ◽  
Yu Wang ◽  
Kuan Li ◽  
Ying-Qiang Wang
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Plant Species ◽  
Population Genetic ◽  
Clonal Plants ◽  
Zingiber Zerumbet ◽  
Population Genetic Diversity ◽  
Local Populations ◽  
High Level

Abstract Background There has always been controversy over whether clonal plants have lower genetic diversity than plants that reproduce sexually. These conflicts could be attributed to the fact that few studies have taken into account the mating system of sexually reproducing plants and their phylogenetic distance. Moreover, most clonal plants in these previous studies regularly produce sexual progeny. Here, we describe a study examining the levels of genetic diversity and differentiation within and between local populations of fully clonal Zingiber zerumbet at a microgeographical scale and compare the results with data for the closely related selfing Z. corallinum and outcrossing Z. nudicarpum. Such studies could disentangle the phylogenetic and sexually reproducing effect on genetic variation of clonal plants, and thus contribute to an improved understanding in the clonally reproducing effects on genetic diversity and population structure. Results The results revealed that the level of local population genetic diversity of clonal Z. zerumbet was comparable to that of outcrossing Z. nudicarpum and significantly higher than that of selfing Z. corallinum. However, the level of microgeographic genetic diversity of clonal Z. zerumbet is comparable to that of selfing Z. corallinum and even slightly higher than that of outcrossing Z. nudicarpum. The genetic differentiation among local populations of clonal Z. zerumbet was significantly lower than that of selfing Z. corallinum, but higher than that of outcrossing Z. nudicarpum. A stronger spatial genetic structure appeared within local populations of Z. zerumbet compared with selfing Z. corallinum and outcrossing Z. nudicarpum. Conclusions Our study shows that fully clonal plants are able not only to maintain a high level of within-population genetic diversity like outcrossing plants, but can also maintain a high level of microgeographic genetic diversity like selfing plant species, probably due to the accumulation of somatic mutations and absence of a capacity for sexual reproduction. We suggest that conservation strategies for the genetic diversity of clonal and selfing plant species should be focused on the protection of all habitat types, especially fragments within ecosystems, while maintenance of large populations is a key to enhance the genetic diversity of outcrossing species.

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