scholarly journals Novel microsatellite DNA markers indicate strict parthenogenesis and few genotypes in the invasive willow sawfly Nematus oligospilus

2012 ◽  
Vol 103 (1) ◽  
pp. 74-88 ◽  
Author(s):  
V. Caron ◽  
M. Norgate ◽  
F.J. Ede ◽  
T. Nyman ◽  
P. Sunnucks
Keyword(s):  
Microsatellite Markers ◽  
Southern Hemisphere ◽  
Genetic Recombination ◽  
Phenotypic Diversity ◽  
Natural Populations ◽  
Population Expansion ◽  
Evolutionary Genetics ◽  
Reproductive Mode ◽  
Invasive Range ◽  
Invasive Organisms

AbstractInvasive organisms can have major impacts on the environment. Some invasive organisms are parthenogenetic in their invasive range and, therefore, exist as a number of asexual lineages (=clones). Determining the reproductive mode of invasive species has important implications for understanding the evolutionary genetics of such species, more especially, for management-relevant traits. The willow sawfly Nematus oligospilus Förster (Hymenoptera: Tenthredinidae) has been introduced unintentionally into several countries in the Southern Hemisphere where it has subsequently become invasive. To assess the population expansion, reproductive mode and host-plant relationships of this insect, microsatellite markers were developed and applied to natural populations sampled from the native and expanded range, along with sequencing of the cytochrome-oxidase I mitochondrial DNA (mtDNA) region. Other tenthredinids across a spectrum of taxonomic similarity to N. oligospilus and having a range of life strategies were also tested. Strict parthenogenesis was apparent within invasive N. oligospilus populations throughout the Southern Hemisphere, which comprised only a small number of genotypes. Sequences of mtDNA were identical for all individuals tested in the invasive range. The microsatellite markers were used successfully in several sawfly species, especially Nematus spp. and other genera of the Nematini tribe, with the degree of success inversely related to genetic divergence as estimated from COI sequences. The confirmation of parthenogenetic reproduction in N. oligospilus and the fact that it has a very limited pool of genotypes have important implications for understanding and managing this species and its biology, including in terms of phenotypic diversity, host relationships, implications for spread and future adaptive change. It would appear to be an excellent model study system for understanding evolution of invasive parthenogens that diverge without sexual reproduction and genetic recombination.

Strong genetic differentiation among populations of Fosterella rusbyi (Bromeliaceae) in Bolivia

2019 ◽  
Vol 192 (4) ◽  
pp. 744-759 ◽  
Author(s):  
Tina Wöhrmann ◽  
Ingo Michalak ◽  
Georg Zizka ◽  
Kurt Weising
Keyword(s):  
Genetic Differentiation ◽  
Microsatellite Markers ◽  
Haplotype Diversity ◽  
Natural Populations ◽  
Population Expansion ◽  
Genetic Distances ◽  
Allopatric Speciation ◽  
Seasonally Dry ◽  
Nuclear Microsatellite ◽  
Suitable Habitats

Abstract The terrestrial bromeliad Fosterella rusbyi is endemic to the Bolivian Andes, where it mainly grows on steep, exposed slopes along roadsides and riverbeds in the seasonally dry tropical forest (SDTF) and the mesic montane forest (Yungas) biomes. We hypothesize that allopatric speciation may have been a main driver of diversification in Fosterella since the Miocene and that the scattered distribution of suitable habitats fostered the evolution of the high degree of endemism observed today. To provide further information relating to this hypothesis, we analysed the partition of genetic diversity and the extent of gene flow among natural populations of F. rusbyi using plastid and nuclear microsatellite markers. Nineteen plastid haplotypes were found, but the mean haplotype diversity per population was low. Nuclear microsatellite markers revealed 177 different multilocus genotypes (MLGs), of which 31 occurred in more than one plant. Recurrent MLGs were found in 76 plants that were therefore identified as clones. A considerable deficit of heterozygotes was detected at all nuclear loci. Geographical and genetic distances between populations were only weakly correlated with each other. Genetic divergence between populations was extremely high for both marker classes, suggesting that seed and pollen flow are low, even over short distances. The observed patterns are consistent with our hypothesis that newly available sites are sporadically colonized by one or a few founders, followed by in situ population expansion via vegetative propagation, self-pollination and/or biparental inbreeding, genetic differentiation among persistent populations and, ultimately, allopatric speciation.

scholarly journals Reproduction in Trypanosomatids: Past and Present

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 471
Author(s):  
Camino Gutiérrez-Corbo ◽  
Bárbara Domínguez-Asenjo ◽  
María Martínez-Valladares ◽  
Yolanda Pérez-Pertejo ◽  
Carlos García-Estrada ◽  
...  
Keyword(s):  
Low Income ◽  
Phenotypic Diversity ◽  
Natural Populations ◽  
Genetic Exchange ◽  
Health Concern ◽  
Current Debate ◽  
Naturally Occurring ◽  
Experimental Works ◽  
Genomic Recombination ◽  
The Impact

Diseases caused by trypanosomatids (Sleeping sickness, Chagas disease, and leishmaniasis) are a serious public health concern in low-income endemic countries. These diseases are produced by single-celled parasites with a diploid genome (although aneuploidy is frequent) organized in pairs of non-condensable chromosomes. To explain the way they reproduce through the analysis of natural populations, the theory of strict clonal propagation of these microorganisms was taken as a rule at the beginning of the studies, since it partially justified their genomic stability. However, numerous experimental works provide evidence of sexual reproduction, thus explaining certain naturally occurring events that link the number of meiosis per mitosis and the frequency of mating. Recent techniques have demonstrated genetic exchange between individuals of the same species under laboratory conditions, as well as the expression of meiosis specific genes. The current debate focuses on the frequency of genomic recombination events and its impact on the natural parasite population structure. This paper reviews the results and techniques used to demonstrate the existence of sex in trypanosomatids, the inheritance of kinetoplast DNA (maxi- and minicircles), the impact of genetic exchange in these parasites, and how it can contribute to the phenotypic diversity of natural populations.

scholarly journals The Regulatory Properties of Autonomous Subtelomeric P Elements Are Sensitive to a Suppressor of variegation in Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 143 (4) ◽  
pp. 1663-1674 ◽  
Author(s):  
Stéphane Ronsseray ◽  
Monique Lehmann ◽  
Danielle Nouaud ◽  
Dominique Anxolabéhère
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Recombination ◽  
Natural Populations ◽  
P Element ◽  
Single Element ◽  
Heterochromatin Protein 1 ◽  
X Chromosomes ◽  
P Elements ◽  
Associated Sequences ◽  
Regulatory Properties

Abstract Genetic recombination was used in Drosophila melanogaster to isolate P elements, inserted at the telomeres of X chromosomes (cytological site 1A) from natural populations, in a genetic background devoid of other P elements. We show that complete maternally inherited P repression in the germline (P cytotype) can be elicited by only two autonomous P elements at 1A and that a single element at this site has partial regulatory properties. The analysis of the surrounding chromosomal regions of the P elements at 1A shows that in all cases these elements are flanked by Telomeric Associated Sequences, tandemly repetitive noncoding sequences that have properties of heterochromatin. In addition, we show that the regulatory properties of P elements at 1A can be inhibited by some of the mutant alleles of the Su(var)205 gene and by a deficiency of this gene. However, the regulatory properties of reference P strains (Harwich and Texas 007) are not impaired by Su(var)205 mutations. Su(var)205 encodes Heterochromatin Protein 1 (HP1). These results suggest that the HP1 dosage effect on the P element properties is sitedependent and could involve the structure of the chromatin.

scholarly journals Evolutionary Genetics and Biogeography of Galaxiid Fishes (Teleostei: Galaxiiformes: Galaxiidae)

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 153
Author(s):  
Graham P. Wallis
Keyword(s):  
Southern Hemisphere ◽  
Evolutionary Genetics ◽  
Widespread Distribution

Since the dawn of the discipline, biogeographers have wondered at the widespread distribution of galaxiid fishes throughout temperate regions of the Southern Hemisphere [...]

Genetic characterization of novel polymorphic microsatellite markers for Epilobium nankotaizanense (Onagraceae), an endemic and threatened herb in Taiwan

2021 ◽  
pp. 1-4
Author(s):  
Yu-Wei Tseng ◽  
Chi-Chun Huang ◽  
Chih-Chiang Wang ◽  
Chiuan-Yu Li ◽  
Kuo-Hsiang Hung
Keyword(s):  
Microsatellite Markers ◽  
Natural Populations ◽  
Conservation Strategy ◽  
Sequencing Data ◽  
Germplasm Collections ◽  
The Family ◽  
Conservation Genetic ◽  
Population Sizes ◽  
Polymorphic Microsatellite

Abstract Epilobium belongs to the family Onagraceae, which consists of approximately 200 species distributed worldwide, and some species have been used as medicinal plants. Epilobium nankotaizanense is an endemic and endangered herb that grows in the high mountains in Taiwan at an elevation of more than 3300 m. Alpine herbs are severely threatened by climate change, which leads to a reduction in their habitats and population sizes. However, only a few studies have addressed genetic diversity and population genetics. In the present study, we developed a new set of microsatellite markers for E. nankotaizanense using high-throughput genome sequencing data. Twenty polymorphic microsatellite markers were developed and tested on 30 individuals collected from three natural populations. These loci were successfully amplified, and polymorphisms were observed in E. nankotaizanense. The number of alleles per locus (A) ranged from 2.000 to 3.000, and the observed (Ho) and expected (He) heterozygosities ranged from 0.000 to 0.929 and from 0.034 to 0.631, respectively. The developed polymorphic microsatellite markers will be useful in future conservation genetic studies of E. nankotaizanense as well as for developing an effective conservation strategy for this species and facilitating germplasm collections and sustainable utilization of other Epilobium species.

Genomic and phenotypic diversity for adaption to future climate in natural populations of perennial ryegrass

2021 ◽  
Author(s):  
José Luis Blanco-Pastor ◽  
Thomas Keep ◽  
Philippe Barre ◽  
Abraham Escobar-Gutiérrez ◽  
Evelin Willner ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Phenotypic Diversity ◽  
Natural Populations ◽  
Future Climate

To what extent do microsatellite markers reflect genome-wide genetic diversity in natural populations?

2008 ◽  
Vol 17 (17) ◽  
pp. 3808-3817 ◽  
Author(s):  
ÜLO VÄLI ◽  
ANNIKA EINARSSON ◽  
LISETTE WAITS ◽  
HANS ELLEGREN
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Markers ◽  
Natural Populations ◽  
Genome Wide

scholarly journals A mechanism for migrating bacterial populations to non-genetically adapt to new environments

2021 ◽  
Author(s):  
Henry H Mattingly ◽  
Thierry Emonet
Keyword(s):  
Collective Behavior ◽  
Group Composition ◽  
Phenotypic Diversity ◽  
Population Expansion ◽  
Migration Speed ◽  
Diverse Population ◽  
Genetic Inheritance ◽  
Bacterial Populations ◽  
Physical Environments ◽  
Varying Environments

Populations of chemotactic bacteria can rapidly expand into new territory by consuming and chasing an attractant cue in the environment, increasing the population's overall growth in nutrient-rich environments. Although the migrating fronts driving this expansion contain cells of multiple swimming phenotypes, the consequences of non-genetic diversity for population expansion are unknown. Here, through theory and simulations, we predict that expanding populations non-genetically adapt their phenotype composition to migrate effectively through multiple physical environments. Swimming phenotypes in the migrating front are spatially sorted by chemotactic performance, but the mapping from phenotype to performance depends on the environment. Therefore, phenotypes that perform poorly localize to the back of the group, causing them to selectively fall behind. Over cell divisions, the group composition dynamically enriches for high-performers, enhancing migration speed and overall growth. Furthermore, non-genetic inheritance controls a trade-off between large composition shifts and slow responsiveness to new environments, enabling a diverse population to out-perform a non-diverse one in varying environments. These results demonstrate that phenotypic diversity and collective behavior can synergize to produce emergent functionalities. Non-genetic inheritance may generically enable bacterial populations to transiently adapt to new situations without mutations, emphasizing that genotype-to-phenotype mappings are dynamic and context-dependent.

scholarly journals Genetic diversity and differentiation in reef-buildingMilleporaspecies, as revealed by cross-species amplification of fifteen novel microsatellite loci

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2936 ◽  
Author(s):  
Caroline E. Dubé ◽  
Serge Planes ◽  
Yuxiang Zhou ◽  
Véronique Berteaux-Lecellier ◽  
Emilie Boissin
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Markers ◽  
Microsatellite Loci ◽  
Natural Populations ◽  
454 Sequencing ◽  
Genetic Distances ◽  
Null Alleles ◽  
Future Research ◽  
Significant Linkage ◽  
Pacific Species

Quantifying the genetic diversity in natural populations is crucial to address ecological and evolutionary questions. Despite recent advances in whole-genome sequencing, microsatellite markers have remained one of the most powerful tools for a myriad of population genetic approaches. Here, we used the 454 sequencing technique to develop microsatellite loci in the fire coralMillepora platyphylla, an important reef-builder of Indo-Pacific reefs.We tested the cross-species amplification of these loci in five other species of the genusMilleporaand analysed its success in correlation with the genetic distances between species using mitochondrial 16S sequences. We succeeded in discovering fifteen microsatellite loci in our target speciesM. platyphylla,among which twelve were polymorphic with 2–13 alleles and a mean observed heterozygosity of 0.411. Cross-species amplification in the five otherMilleporaspecies revealed a high probability of amplification success (71%) and polymorphism (59%) of the loci. Our results show no evidence of decreased heterozygosity with increasing genetic distance. However, only one locus enabled measures of genetic diversity in the Caribbean speciesM. complanatadue to high proportions of null alleles for most of the microsatellites. This result indicates that our novel markers may only be useful for the Indo-Pacific species ofMillepora.Measures of genetic diversity revealed significant linkage disequilibrium, moderate levels of observed heterozygosity (0.323–0.496) and heterozygote deficiencies for the Indo-Pacific species. The accessibility to new polymorphic microsatellite markers for hydrozoanMilleporaspecies creates new opportunities for future research on processes driving the complexity of their colonisation success on many Indo-Pacific reefs.

scholarly journals Molecular population genetics of sequence length diversity in the Adh region of Drosophila pseudoobscura

2002 ◽  
Vol 80 (3) ◽  
pp. 163-175 ◽  
Author(s):  
STEPHEN W. SCHAEFFER
Keyword(s):  
Negative Selection ◽  
Genome Rearrangement ◽  
Rare Variants ◽  
Natural Populations ◽  
Population Expansion ◽  
Purifying Selection ◽  
Sequence Length ◽  
Nucleotide Sequence Analysis ◽  
Drosophila Pseudoobscura ◽  
Indel Variation

Positive and negative selection on indel variation may explain the correlation between intron length and recombination levels in natural populations of Drosophila. A nucleotide sequence analysis of the 3·5 kilobase sequence of the alcohol dehydrogenase (Adh) region from 139 Drosophila pseudoobscura strains and one D. miranda strain was used to determine whether positive or negative selection acts on indel variation in a gene that experiences high levels of recombination. A total of 30 deletion and 36 insertion polymorphisms were segregating within D. pseudoobscura populations and no indels were fixed between D. pseudoobscura and its two sibling species D. miranda and D. persimilis. The ratio of Tajima's D to its theoretical minimum value (Dmin) was proposed as a metric to assess the heterogeneity in D among D. pseudoobscura loci when the number of segregating sites differs among loci. The magnitude of the D/Dmin ratio was found to increase as the rate of population expansion increases, allowing one to assess which loci have an excess of rare variants due to population expansion versus purifying selection. D. pseudoobscura populations appear to have had modest increases in size accounting for some of the observed excess of rare variants. The D/Dmin ratio rejected a neutral model for deletion polymorphisms. Linkage disequilibrium among pairs of indels was greater than between pairs of segregating nucleotides. These results suggest that purifying selection removes deletion variation from intron sequences, but not insertion polymorphisms. Genome rearrangement and size-dependent intron evolution are proposed as mechanisms that limit runaway intron expansion.

Sign in / Sign up

Export Citation Format

Share Document