THE ORGANIZATION OF GENETIC DIVERSITY IN THE PARTHENOGENETIC LIZARD CNEMIDOPHORUS TESSELATUS

ABSTRACT The parthenogenetic lizard species Cnemidophorus tesselatus is composed of diploid populations formed by hybridization of the bisexual species C. tigris and C. septemvittatus, and of triploid populations derived from a cross between diploid tesselatus and a third bisexual species, C. sexlineatus. An analysis of allozymic variation in proteins encoded by 21 loci revealed that, primarily because of hybrid origin, individual heterozygosity in tesselatus is much higher (0.560 in diploids and 0.714 in triploids) than in the parental bisexual species (mean, 0.059). All triploid individuals apparently represent a single clone, but 12 diploid clones were identified on the basis of genotypic diversity occurring at six loci. From one to four clones were recorded in each population sampled. Three possible sources of clonal diversity in the diploid parthenogens were identified: mutation at three loci has produced three clones, each confined to a single locality; genotypic diversity at two loci apparently caused by multiple hybridization of the bisexual species accounts for four clones; and the remaining five clones apparently have arisen through recombination at three loci. The relatively limited clonal diversity of tesselatus suggests a recent origin. The evolutionary potential of tesselatus and of parthenogenetic forms in general may be less severely limited than has generally been supposed.

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Temporal genotypic diversity of Schizaphis graminum (Rondani 1852) (Hemiptera: Aphididae) in a black oats (Avena strigosa) field

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132010000400021 ◽

2010 ◽

Vol 53 (4) ◽

pp. 911-916 ◽

Cited By ~ 2

Author(s):

Marcelo Lopes-da-Silva ◽

Luiz Gonzaga Esteves Vieira

Keyword(s):

Rapd Markers ◽

Clonal Diversity ◽

Genotypic Diversity ◽

Schizaphis Graminum ◽

Dna Polymorphisms ◽

Information Index ◽

Avena Strigosa ◽

Geographical Scale ◽

Single Clone ◽

Phenological Cycle

The aim of this work was to analyze the clonal diversity variation in Schizaphis graminum during a complete phenological cycle of black oats (Avena strigosa). RAPD markers were used for detection of DNA polymorphisms of each clonal lineage, derived from a single clone collected weekly during a period of four months, in a crop field of black oats, Londrina, Paraná, Brazil. The monthly genotypic diversity was estimated by Shannon Information Index (H). Only four genotypes were distinguished from 122 specimens, with one of them overly predominant in all sampling dates (>60%). Another genotype, apparently a later colonizer, rapidly reached greater frequency than other genotypes on the second and third month. The results of this work suggested that temporal genotypic diversity of S. graminum assessed by RAPD markers was small and less variable than the genetic variation found at geographical scale.

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Cytotype variation and clonal diversity in polyploid apomictic populations of Pilosella (Compositeae, Cichorieae) introduced to southern Patagonia

Boletín de la Sociedad Argentina de Botánica ◽

10.31055/1851.2372.v56.n3.32767 ◽

2021 ◽

Vol 56 (3) ◽

Author(s):

Anna Krahulcová ◽

František Krahulec

Keyword(s):

Clonal Diversity ◽

Hybrid Origin ◽

Cultivated Plants ◽

Increased Risk ◽

Southern Patagonia ◽

Clonal Identity ◽

Species Population ◽

Residual Sexuality ◽

Two Populations ◽

A New Species

Introduction and objectives: The members of the genus Pilosella are native in Europe and Asia, but they are successful invasive species on most continents. These species form an agamic complex with common apomixis. Apomictic species hybridize, they have different degree of residual sexuality. Main aim of this paper was to determine if the interspecific hybridization already occurred in Patagonia. M&M: This study is based on analysis of seed progeny collected at thirteen populations of Pilosella in southern Argentina and Chile. The plants were examined for their taxonomic identity, DNA ploidy level (using flow cytometry), chromosome number, reproduction, formation of parthenogenetic seeds and clonal identity (using isozyme phenotypes). Results: No mixed-species population was recorded. Two apomictic clones of P. officinarum (one pentaploid and the other hexaploid) were found in populations: eight were hexaploid and one was mixed in cytotype composition. A new species for Patagonia, the apomictic pentaploid P. caespitosa, was represented by plants from two populations in Argentina. Some of the progeny plants cultivated from seeds sampled at three localities represented seed-fertile aneuploids the morphology of which implied a hybrid origin and indicated P. officinarum as one of the parents. Conclusions: The presence of seed-fertile, aneuploid and parthenogenetic hybrids among the cultivated plants signifies an increased risk of the formation of new hybridogeneous genotypes of Pilosella in southern Patagonia.

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Reciprocal hybridization between diploid Ficaria calthifolia and tetraploid Ficaria verna subsp. verna: evidence from experimental crossing, genome size and molecular markers

Botanical Journal of the Linnean Society ◽

10.1093/botlinnean/boy085 ◽

2019 ◽

Vol 189 (3) ◽

pp. 293-310 ◽

Cited By ~ 1

Author(s):

Ondřej Popelka ◽

Michal Sochor ◽

Martin Duchoslav

Keyword(s):

Genome Size ◽

Morphological Variability ◽

Plastid Dna ◽

Genotypic Diversity ◽

Hybrid Origin ◽

Aflp Analysis ◽

Sympatric Populations ◽

Aflp Data ◽

Evolutionary Forces ◽

Genetic Clusters

Abstract Ficaria is a taxonomically intriguing polyploid complex with high morphological variability. Both hybridization and polyploidization have been suggested as the main evolutionary forces behind the high morphological variability in this genus; however, detailed studies are lacking. In Central Europe, two Ficaria taxa (diploid F. calthifolia and tetraploid F. verna subsp. verna) occasionally co-occur in local sympatry, which might result in hybridization. We investigated sympatric populations of the two Ficaria taxa using flow cytometry, chromosome counts, AFLP analysis and plastid DNA sequencing; we also performed experimental homoploid and heteroploid crosses to determine the frequency and direction of hybrid triploid formation, an alternative route of triploid origin (autopolyploidy) and the possibility of a one-step neoallotetraploid origin. Sympatric populations were composed of three genetic clusters corresponding to diploid F. calthifolia (2n = 16), tetraploid F. verna subsp. verna (2n = 32) and triploid plants (2n = 24). The holoploid genome size and AFLP data suggest a hybrid origin of the triploids, thereby making their formation via autopolyploidization in F. calthifolia unlikely. The triploid populations are monoclonal and of independent origin. In contrast, the parental populations exhibit high genotypic diversity and frequent sexual reproduction, including those of predominantly asexual F. verna subsp. verna. Experimental crossing confirmed that both parental taxa produce fertile seeds via a sexual pathway, but not by apomixis, and that both serve as pollen acceptors in heteroploid crosses, which is consistent with the plastid sequencing. However, hybridization is asymmetric, with maternal-excess crosses being significantly more successful. No signs of neoautotetraploidization or neoallotetraploidization were detected. In summary, recent gene flow between the studied Ficaria taxa is either limited or absent.

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Speciation by hybridization in phasmids and other insects

Canadian Journal of Zoology ◽

10.1139/z90-256 ◽

1990 ◽

Vol 68 (8) ◽

pp. 1747-1760 ◽

Cited By ~ 50

Author(s):

Luciano Bullini ◽

Giuseppe Nascetti

Keyword(s):

Hybrid Origin ◽

Clonal Variation ◽

Female Reproduction ◽

Bisexual Species ◽

Hybrid Species ◽

Carausius Morosus ◽

Origin And Evolution ◽

Parthenogenetic Development ◽

Hybrid Genome ◽

Disturbed Habitats

Speciation by hybridization in insects has been recently recognized on the basis of isozyme and chromosome studies showing that several species, either diploid or polyploid, have genomes that combine the genes and chromosome sets of two (or more) bisexual species. Until this evidence became available, thelytokous invertebrates were all considered uniparental derivatives of bisexual species. In this paper, we review examples including the stick insects Bacillus whitei, B. atticus, B. lynceorum, Leptynia hispanica D, Clonopsis gallica, Carausius morosus; the grasshopper Warramaba virgo; some Otiorrhynchus weevils; the planthopper Muellerianella 2-fairmairei–brevipennis; and black flies of the genera Gymnopais and Prosimulium. For several species (e.g., Warramaba virgo and Bacillus whitei), both parental taxa have been recognized, and their hybrid origin has been genetically assessed. In others (e.g., B. atticus), only one of the bisexual parental species has been detected; but their hybrid origin is supported by strong evidence, at both the isozyme and chromosome levels. For other supposed hybrid species (e.g., Clonopsis gallica, Carausius morosus), no bisexual ancestors have been detected, possibly because competition with their hybrid derivatives has made them rare or extinct. Insect hybrid species may differ in their mode of reproduction (apomictic or automictic thelytokous parthenogenesis, gynogenesis), degree of ploidy, and genetic structure (level of heterozygosity, clonal variation). The parallels between insect and vertebrate hybrid species, in which this phenomenon has been recognized and widely studied in the past 50 years, are drawn. The main problems involved in the origin and evolution of hybrid species are discussed, with particular regard to (i) changes in the maturation divisions allowing the transmission of the hybrid genome to the next generation, and (ii) their successful adaptation. The "spontaneous" and "hybrid" theories for the origin of unisexual forms are compared, with regard to hybrid species. An origin of hybrid species from occasional parthenogenetic development of hybrid eggs produced in areas of extensive interspecific hybridization (e.g., disturbed habitats) is suggested. Hybridization would not itself cause changes in the maturation divisions (which are controlled by genes of tychoparthenogenetic eggs) but only favour their selection through heterosis. The role of the so-called "heterotic" advantage (resulting from high levels of heterozygosity) and "demographic" advantage (resulting from all-female reproduction) in the evolutionary success of hybrid species is discussed. It is concluded that habitat disturbance by man is favouring both the onset of hybrid species and their successful spread.

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Spatial Distribution of Rhodopseudomonas palustris Ecotypes on a Local Scale

Applied and Environmental Microbiology ◽

10.1128/aem.69.9.5192-5197.2003 ◽

2003 ◽

Vol 69 (9) ◽

pp. 5192-5197 ◽

Cited By ~ 29

Author(s):

S. J. Bent ◽

C. L. Gucker ◽

Y. Oda ◽

L. J. Forney

Keyword(s):

Spatial Distribution ◽

Rhodopseudomonas Palustris ◽

Sampling Site ◽

Clonal Diversity ◽

Genotypic Diversity ◽

Rrna Gene ◽

Similarity Coefficients ◽

16S Rrna Gene Sequences ◽

Multiple Strains ◽

Rank Abundance

ABSTRACT The number, spatial distribution, and significance of genetically distinguishable ecotypes of prokaryotes in the environment are poorly understood. Oda et al. (Y. Oda, B. Star, L. A. Huisman, J. C. Gottschal, and L. J. Forney, Appl. Environ. Microbiol. 69:xxx-xxx, 2003) have shown that Rhodopseudomonas palustris ecotypes were lognormally distributed along a 10-m transect and that multiple strains of the species could coexist in 0.5-g sediment samples. To extend these observations, we investigated the clonal diversity of R. palustris in 0.5-g samples taken from the corners and center of a 1-m square. A total of 35 or 36 clones were recovered by direct plating from each sample and were characterized by BOX A1R repetitive element-PCR genomic DNA fingerprinting. Isolates with fingerprint images that were ≥80% similar to each other were defined as the same genotype. Among the 178 isolates studied, 32 genotypes were identified, and each genotype contained between 1 and 40 isolates. These clusters were consistent with minor variations found in 16S rRNA gene sequences. The Shannon indices of the genotypic diversity within each location ranged from 1.08 (5 genotypes) to 2.18 (13 genotypes). Comparison of the rank abundance of genotypes found in pairs of locations showed that strains from three locations were similar to each other, with Morisita-Horn similarity coefficients ranging from 0.59 to 0.71. All comparisons involving the remaining two locations resulted in coefficients between 0 and 0.12. From these results we inferred that the patterns of ecotype diversity at the sampling site are patchy at a 1-m scale and postulated that factors such as mixing, competitive interactions, and microhabitat variability are likely to be responsible for the maintenance of the similarities between some locations and the differences between others.

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Clonal Structure of Some Weevil Species (Coleoptera, Curculionidae) From Central Ukraine

Vestnik Zoologii ◽

10.2478/vzoo-2018-0033 ◽

2018 ◽

Vol 52 (4) ◽

pp. 313-322

Author(s):

V. Yu. Nazarenko ◽

S. Yu. Morozov-Leonov

Keyword(s):

Clonal Diversity ◽

Hybrid Origin ◽

Clonal Variation ◽

Clonal Structure ◽

Weevil Species ◽

Electrophoretic Spectra

Abstract The clonal structure of the populations of nine weevil species (family Curculionidae) from central Ukraine was analyzed. Clonal diversity varied extensively among studied species. Th e level of clonal variation of some species (Otiorhynchus ligustici, O. raucus, Liophloeus tessulatus) is high, within some other species (O. tristis, Tropiphorus micans) it is low. Th e constant heterozygosity of lot of genes has been demonstrated that it may be a proof of the hybrid origin of the studied weevil populations. Th e asymmetry of some obtained electrophoretic spectra was observed. Th is can be a consequence of their polyploid nature. Th e signifi cant interpopulation diff erentiation of most of the species studied was demonstrated.

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Histocompatibility analysis of clonal diversity in unisexual hybrids of the killifishes Fundulus heteroclitus and Fundulus diaphanus

Canadian Journal of Zoology ◽

10.1139/z00-018 ◽

2000 ◽

Vol 78 (6) ◽

pp. 923-930 ◽

Cited By ~ 7

Author(s):

Robert M Dawley ◽

Amy M Yeakel ◽

Keith A Beaulieu ◽

Kristen L Phiel

Keyword(s):

Nova Scotia ◽

Fundulus Heteroclitus ◽

Atlantic Coast ◽

Clonal Diversity ◽

Immune Systems ◽

Single Clone ◽

Individual Scale ◽

Fundulus Diaphanus

Hybrids of the killifishes Fundulus diaphanus and Fundulus heteroclitus, found at two sites on the Atlantic coast of Nova Scotia, are unisexual diploid gynogens. Because there seemed to be many opportunities for the sexual progenitor species to hybridize and form new clones at these sites, we initially had expected that clonal diversity might be high among the hybrids. However, examination of their histocompatibility genomes, via inter-individual scale grafting, provides evidence, albeit not conclusive, that most of the hybrids at the two sites, which are separated by 125 km, comprise a single clone. Grafts made among F. diaphanus were rejected within an average of 16-20 days, establishing that sufficient diversity exists within the histocompatibility genomes of these fish to permit their immune systems to reject foreign melanophores. Grafts made from F. diaphanus to the hybrids were also rejected, within an average of 17-26 days, demonstrating that the hybrids possessed competent immune systems. Grafts made between hybrids were nearly always accepted. Those few that appeared to be rejected were usually accepted when regrafted. Melanophores carried on the graft remained visible for the duration of the study (90-180 days) or, if they slowly disappeared, they did so at a rate comparable with that of autograft scales.

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Genotypic diversity and virulence traits of Streptococcus mutans in caries-free and caries-active individuals

Journal of Medical Microbiology ◽

10.1099/jmm.0.05512-0 ◽

2004 ◽

Vol 53 (7) ◽

pp. 697-703 ◽

Cited By ~ 59

Author(s):

Marcelo Henrique Napimoga ◽

Regianne Umeko Kamiya ◽

Rosimeire Takaki Rosa ◽

Edvaldo AntonioR. Rosa ◽

José Francisco Höfling ◽

...

Keyword(s):

Streptococcus Mutans ◽

Glass Surface ◽

Genetic Relatedness ◽

Clonal Diversity ◽

Genotypic Diversity ◽

Pcr Analysis ◽

Enzyme Electrophoresis ◽

Bacterial Cells ◽

Virulence Traits ◽

Significant Difference

The present study evaluated the relationship between clonal diversity and some virulence traits of Streptococcus mutans isolated from eight caries-free and eight caries-active subjects. A total of 155 S. mutans isolates from caries-free subjects and 144 isolates from caries-active subjects were obtained from samples of saliva, dental plaque and tongue surface and identified by PCR. The isolates were submitted to arbitrarily primed (AP)-PCR (OPA-2 and OPA-13) and multilocus enzyme electrophoresis (MLEE) to establish the genotypic diversity. Production of water-insoluble glucan (WIG) (monitored by SDS-PAGE), final pH of cultures and the ability of bacterial cells to adhere to smooth glass in the presence of sucrose were measured. High and comparable abilities of MLEE and AP-PCR were found to distinguish S. mutans genotypes, using Simpson's index of discrimination (0.971 and 0.968, respectively). The results showed a significant difference (P < 0.01) in the number of genotypes when caries-free and caries-active groups were compared by both fingerprinting methods used. Final pH (P = 0.32) and the percentage of adherence to a glass surface (P = 0.62) did not show differences between the two groups; however, the intensities of WIG bands from the caries-active group were greater than those from the caries-free group (P < 0.01). In addition, WIG was positively correlated with the ability of S. mutans to adhere to a glass surface (r = 0.34, P = 0.02) from caries-active subjects. These data showed that AP-PCR analysis and MLEE are both effective methods for assessing the genetic relatedness of S. mutans. Using these techniques, it was found that there is a larger number of genotypes of S. mutans with increased ability to synthesize WIG in caries-active individuals.

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Spatial patterns of tumour growth impact clonal diversification: computational modelling and evidence in the TRACERx Renal study

10.21203/rs.3.rs-244285/v1 ◽

2021 ◽

Author(s):

Xiao Fu ◽

Yue Zhao ◽

Jose Lopez ◽

Andrew Rowan ◽

Lewis Au ◽

...

Keyword(s):

Spatial Patterns ◽

Time Course ◽

Tumour Growth ◽

Early Stage ◽

Parallel Evolution ◽

Computational Modelling ◽

Clonal Diversity ◽

Cancer Evolution ◽

Evolutionary Potential ◽

Spatially Resolved

Abstract Intra-tumour genetic heterogeneity (ITH) fuels cancer evolution. The role of clonal diversity and genetic complexity in the progression of clear-cell renal cell carcinomas (ccRCCs) has been characterised, but the ability to predict clinically relevant evolutionary trajectories remains limited. Here, towards enhancing this ability, we investigated spatial features of clonal diversification through a combined computational modelling and experimental analysis in the TRACERx Renal study. We observe through modelling that spatial patterns of tumour growth impact the extent and trajectory of subclonal diversification. Moreover, subpopulations with high clonal diversity, and parallel evolution events, are frequently observed near the tumour margin. In-silico time-course studies further showed that budding structures on the tumour surface could indicate future steps of subclonal evolution. Such structures were evident radiologically in 15 early-stage ccRCCs, raising the possibility that spatially resolved sampling of these regions, when combined with sequencing, may enable identification of evolutionary potential in early-stage tumours.

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