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Bengt Olle Bengtsson - One of the best experts on this subject based on the ideXlab platform.
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structure of the natural transgene pgic2 in the common grass Festuca ovina
PLOS ONE, 2010Co-Authors: Pernilla Vallenback, Lena Ghatnekar, Bengt Olle BengtssonAbstract:Background: A horizontal gene transfer has brought an active nuclear gene, PgiC2, from a polyploid Poa species (P. palustris or a close relative) into the common grass sheep’s fescue (Festuca ovina). The donor and the receptor species are strictly reproductively separated, and PgiC2 occurs in a polymorphic state within F. ovina. The active gene copy is normally closely linked to a very similar pseudogene. Methodology/Principal Findings: By genome walking we have obtained the up- and downstream sequences of PgiC2 and of corresponding genes in the donor and recipient species. Comparisons of these sequences show that the complete upstream region necessary for the gene’s expression is included in the transferred segment. About 1 kb upstream of PgiC2 a fragment with transposition associated properties has been found (TAF). It is present in P. palustris and its polyploid relatives, though not at the homologous position, and is absent from many other grasses, including non-transgenic F. ovina plants. It is possible that it is a part of a transposing element involved in getting the gene into a transferring agent and/or into the recipient chromosome. Conclusions/Significance: The close similarity of the up- and downstream regions with the corresponding regions in P. palustris excludes all suggestions that PgiC2 is not a HGT but the result of a duplication within the F. ovina lineage. The small size of the genetic material transferred, the complex nature of the PgiC2 locus, and the associated fragment with transposition associated properties suggest that the horizontal transfer occurred via a vector and not via illegitimate pollination.
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origin and timing of the horizontal transfer of a pgic gene from poa to Festuca ovina
Molecular Phylogenetics and Evolution, 2008Co-Authors: Pernilla Vallenback, Lena Ghatnekar, Maarit Jaarola, Bengt Olle BengtssonAbstract:A segregating second locus, PgiC2, for the enzyme phosphoglucose isomerase (PGIC) is found in the grass sheep's fescue, Festuca ovina. We have earlier reported that a phylogenetic analysis indicates that PgiC2 has been horizontally transferred from the reproductively separated grass genus Poa. Here we extend our analysis to include intron and exon information on 27 PgiC sequences from 18 species representing five genera, and confirm our earlier finding. The origin of PgiC2 can be traced to a group of closely interrelated, polyploid and partially asexual Poa species. The sequence most similar to PgiC2 is found in Poa palustris with a divergence, based on synonymous substitutions, of only 0.67%. This value suggests that the transfer took place less than 600,000 years ago (late Pleistocene), at a time when most extant Poa and Festuca species already existed.
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the introgression of a functional nuclear gene from poa to Festuca ovina
Proceedings of The Royal Society B: Biological Sciences, 2006Co-Authors: Lena Ghatnekar, Maarit Jaarola, Bengt Olle BengtssonAbstract:In sheep's fescue, Festuca ovina, genes coding for the cytosolic enzyme phosphoglucose isomerase, PGIC, are not only found at the standard locus, PgiC1, but also at a segregating second locus, PgiC2. We have used PCR-based sequencing to characterize the molecular structure and evolution of five PgiC1 and three PgiC2 alleles in F. ovina. The three PgiC2 alleles were complex in that they carried two gene copies: either two active genes or one active and one pseudogene. All the PgiC2 sequences were very similar to each other but highly diverged from the five PgiC1 sequences. We also sequenced PgiC genes from several other grass species. Phylogenetic analysis of these sequences indicates that PgiC2 has introgressed into F. ovina from the distant genus Poa. Such an introgression may, for example, follow from a non-standard fertilization with more than one pollen grain, or a direct horizontal gene transfer mediated by a plant virus.
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the loss of alleles by sampling a study of the common outbreeding grass Festuca ovina over three geographic scales
Hereditas, 2004Co-Authors: Bengt Olle Bengtsson, Peder Weibull, Lena GhatnekarAbstract:In three investigations of the common outbreeding grass Festuca ovina The geographic variation of alleles was studied. The aim was to determine the role this variability has on the probability that an allele is lost from a particular sample, (i) In the investigation of Skane, where 35 populations were studied for 12 independent alleles, it was found that the probability of loss as a function of an allele's overall frequency was increased compared to the null-hypothesis of its frequency being the same in all populations. This implies that genes in a particular sample are only partly informative about the genetic composition of the area as a whole. A method is described how to calculate this degree of representativity, R. In the investigation of Skane, with an average of 33 analysed genes per sample, the estimated value for R was 0.68. This value can be taken as an upper estimate of R for other herbaceous plants, since the investigated system was chosen to be as homogeneous and have as high an R value as possible, (ii) From a study of 16 samples from the whole of Fennoscandia could be concluded that sampling populations with different post-glacial histories is an effective way of increasing the number of recorded alleles. (iii) A study of seeds from seven selected plants in a local population at Vomb in Skane, showed that the allele frequencies vary significantly between the pollen clouds that fertilize different individual plants. Thus, in a plant as outbreeding as Festuca ovina, genetic variability is pronounced at the smallest and the largest geographic scales, but is weak at the intermediary scale.
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a dna marker for the duplicated cytosolic pgi genes in sheep s fescue Festuca ovina l
Genetics Research, 2000Co-Authors: Lena Ghatnekar, Bengt Olle BengtssonAbstract:Active duplicate PgiC genes in sheep's fescue, Festuca ovina, are associated with a PCR marker of specific length (about 370 bp, of which 231 are in an intron). Using this marker, the frequency of plants with duplicate genes is estimated to be about 10% in a population from southern Sweden. The close molecular similarity between the electrophoretically different duplicated genes is in accordance with the conclusion reached earlier that they are indeed alleles at the same locus.
Lena Ghatnekar - One of the best experts on this subject based on the ideXlab platform.
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contrasting patterns of nucleotide polymorphism suggest different selective regimes within different parts of the pgic1 gene in Festuca ovina l
Hereditas, 2017Co-Authors: Bengt Hansson, Lena Ghatnekar, Honor C. PrenticeAbstract:Phosphoglucose isomerase (PGI, EC 5.3.1.9) is an essential metabolic enzyme in all eukaryotes. An earlier study of the PgiC1 gene, which encodes cytosolic PGI in the grass Festuca ovina L., revealed a marked difference in the levels of nucleotide polymorphism between the 5’ and 3’ portions of the gene. In the present study, we characterized the sequence polymorphism in F. ovina PgiC1 in more detail and examined possible explanations for the non-uniform pattern of nucleotide polymorphism across the gene. Our study confirms that the two portions of the PgiC1 gene show substantially different levels of DNA polymorphism and also suggests that the peptide encoded by the 3’ portion of PgiC1 is functionally and structurally more important than that encoded by the 5’ portion. Although there was some evidence of purifying selection (d N/d S test) on the 5’ portion of the gene, the signature of purifying selection was considerably stronger on the 3’ portion of the gene (d N/d S and McDonald–Kreitman tests). Several tests support the action of balancing selection within the 5’ portion of the gene. Wall’s B and Q tests were significant only for the 5’ portion of the gene. There were also marked peaks of nucleotide diversity, Tajima’s D and the d N/d S ratio at or around a PgiC1 codon site (within the 5’ portion of the gene) that a previous study had suggested was subject to positive diversifying selection. Our results suggest that the two portions of the gene have been subject to different selective regimes. Purifying selection appears to have been the main force contributing to the relatively low level of polymorphism within the 3’ portion of the sequence. In contrast, it is possible that balancing selection has contributed to the maintenance of the polymorphism within the 5’ portion of the gene.
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Contrasting patterns of nucleotide polymorphism suggest different selective regimes within different parts of the PgiC1 gene in Festuca ovina L.
Hereditas, 2017Co-Authors: Bengt Hansson, Lena Ghatnekar, Honor C. PrenticeAbstract:Background Phosphoglucose isomerase (PGI, EC 5.3.1.9) is an essential metabolic enzyme in all eukaryotes. An earlier study of the PgiC1 gene, which encodes cytosolic PGI in the grass Festuca ovina L., revealed a marked difference in the levels of nucleotide polymorphism between the 5’ and 3’ portions of the gene. Methods In the present study, we characterized the sequence polymorphism in F. ovina PgiC1 in more detail and examined possible explanations for the non-uniform pattern of nucleotide polymorphism across the gene. Results Our study confirms that the two portions of the PgiC1 gene show substantially different levels of DNA polymorphism and also suggests that the peptide encoded by the 3’ portion of PgiC1 is functionally and structurally more important than that encoded by the 5’ portion. Although there was some evidence of purifying selection ( d _N/ d _S test) on the 5’ portion of the gene, the signature of purifying selection was considerably stronger on the 3’ portion of the gene ( d _N/ d _S and McDonald–Kreitman tests). Several tests support the action of balancing selection within the 5’ portion of the gene. Wall’s B and Q tests were significant only for the 5’ portion of the gene. There were also marked peaks of nucleotide diversity, Tajima’s D and the d _N/ d _S ratio at or around a PgiC1 codon site (within the 5’ portion of the gene) that a previous study had suggested was subject to positive diversifying selection. Conclusions Our results suggest that the two portions of the gene have been subject to different selective regimes. Purifying selection appears to have been the main force contributing to the relatively low level of polymorphism within the 3’ portion of the sequence. In contrast, it is possible that balancing selection has contributed to the maintenance of the polymorphism within the 5’ portion of the gene.
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Ghatnekar L. Geographic and molecular variation in a natural plant transgene
2016Co-Authors: Pernilla Vallenback, Bengt O. Bengtsson, Lena GhatnekarAbstract:Abstract A PCR based survey of Festuca ovina plants from populations around the southern part of the Baltic Sea demonstrates both geographic and molecular variation in the enzyme gene PgiC2, horizontally transferred from a Poa-species. Our results show that PgiC2—a natural functional nuclear transgene—is not a local ephemeral phenomenon but is present in a very large number of individuals. We find also that its frequency is geographi-cally variable and that it appears in more than one molecular form. The chloroplast variation in the region does not indicate any distinct subdivision due to different colonization routes after the last glaciation. Our data illustrate the geographic and molecular variation that may occur in natural populations with a polymorphic, unfixed transgene affected by diverse kinds of mutational and evolutionary processes
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structure of the natural transgene pgic2 in the common grass Festuca ovina
PLOS ONE, 2010Co-Authors: Pernilla Vallenback, Lena Ghatnekar, Bengt Olle BengtssonAbstract:Background: A horizontal gene transfer has brought an active nuclear gene, PgiC2, from a polyploid Poa species (P. palustris or a close relative) into the common grass sheep’s fescue (Festuca ovina). The donor and the receptor species are strictly reproductively separated, and PgiC2 occurs in a polymorphic state within F. ovina. The active gene copy is normally closely linked to a very similar pseudogene. Methodology/Principal Findings: By genome walking we have obtained the up- and downstream sequences of PgiC2 and of corresponding genes in the donor and recipient species. Comparisons of these sequences show that the complete upstream region necessary for the gene’s expression is included in the transferred segment. About 1 kb upstream of PgiC2 a fragment with transposition associated properties has been found (TAF). It is present in P. palustris and its polyploid relatives, though not at the homologous position, and is absent from many other grasses, including non-transgenic F. ovina plants. It is possible that it is a part of a transposing element involved in getting the gene into a transferring agent and/or into the recipient chromosome. Conclusions/Significance: The close similarity of the up- and downstream regions with the corresponding regions in P. palustris excludes all suggestions that PgiC2 is not a HGT but the result of a duplication within the F. ovina lineage. The small size of the genetic material transferred, the complex nature of the PgiC2 locus, and the associated fragment with transposition associated properties suggest that the horizontal transfer occurred via a vector and not via illegitimate pollination.
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origin and timing of the horizontal transfer of a pgic gene from poa to Festuca ovina
Molecular Phylogenetics and Evolution, 2008Co-Authors: Pernilla Vallenback, Lena Ghatnekar, Maarit Jaarola, Bengt Olle BengtssonAbstract:A segregating second locus, PgiC2, for the enzyme phosphoglucose isomerase (PGIC) is found in the grass sheep's fescue, Festuca ovina. We have earlier reported that a phylogenetic analysis indicates that PgiC2 has been horizontally transferred from the reproductively separated grass genus Poa. Here we extend our analysis to include intron and exon information on 27 PgiC sequences from 18 species representing five genera, and confirm our earlier finding. The origin of PgiC2 can be traced to a group of closely interrelated, polyploid and partially asexual Poa species. The sequence most similar to PgiC2 is found in Poa palustris with a divergence, based on synonymous substitutions, of only 0.67%. This value suggests that the transfer took place less than 600,000 years ago (late Pleistocene), at a time when most extant Poa and Festuca species already existed.
R Haveman - One of the best experts on this subject based on the ideXlab platform.
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het Festuca ovina complex in nederland 3 de smalbladige schapengrassen
Gorteria, 2015Co-Authors: R HavemanAbstract:After a reply to De Wilde-Duyfjes, who commented on an earlier published treatment of the relatively broad-leaved sheep fescues, the Dutch small-leaved sheep fescues are discussed. Taxonomy and nomenclature of the small-leaved sheep fescues closely related to Festuca ovina is confusing. Until 2005, Dutch literature only recognised two taxa: F. filiformis Pourr. and F. ovina L. In Belgium, Great-Britain and Germany at least four taxa have been recognised: F. ovina subsp. hirtula (Hack. ex Travis) M.J.Wilk. and F. ovina subsp. ophioliticola (Kerguelen) M.J.Wilk. (= F. guestfalica Boenn. ex Reichb), as well as the two taxa already mentioned. In this paper, it is argued that the tetraploid taxa are best considered as subspecies of F. guestfalica Boenn. ex Reichb. and separate from F. ovina. Morphometric analysis of a part of the collection of the herbarium of Naturalis in Leiden (L) and the herbarium of the author revealed that all four taxa can be distiguished in the Netherlands as well. Festuca filiformis is the most common one and occurs on acidic and mostly sandy soils all over the country. Festuca guestfalica subsp. hirtula is quite common on acidic sandy soil of the lateral moraines and blown outs in the central part of the country (Veluwe). Festuca guestfalica subsp. guestfalica occurs in South Limburg, where it grows on heavy metal soils in the floodplain of the River Geul. The subspecies is extremely rare and in such decline there that it has locally become almost extinct. Recently, however, it was found on chalk outcrops in South Limburg and at a single locality in the Veluwe. Possibly, the subspecies may occur at other localities outside its known distribution area as well. Two collections from Apeldoorn, collected in the 19th century, probably belong to Festuca ovina. No recent collections of this species are known.
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het Festuca ovina complex in nederland 4 Festuca csikhegyensis simonk op het harskampse zand
Gorteria, 2015Co-Authors: R HavemanAbstract:During the inventory of the military firing range east of the village of Harskamp on the Veluwe, Province of Gelderland, in 2003, Festuca csikhegyensis Simonk. was discovered. This species includes the tetraploid populations formerly included in F. pallens Host. In this paper, F. csikhegyensis is briefly described. Based on a phytosociological releve it is shown that F. csikhegyensis grows in somewhat disturbed shifting sand communities belonging to the Cetrario aculetae-Corynephoretum. Probably, the population of Festuca csikhegyensis at the Harskamp finds its origin in an unintended anthropogeneous introduction.
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het Festuca ovina complex in nederland 2 f lemanii bast en f brevipila tracey
Gorteria, 2005Co-Authors: R HavemanAbstract:In de Nederlandse flora’s worden de grofbladige schapengrassen met lange naalden samengevat onder Festuca cinerea Vill. Dit taxon blijkt echter een klein areaal te hebben dat beperkt is tot Zuidoost-Frankrijk. Andere namen die in de literatuur worden genoemd voor deze grofbladige schapengrassen in Nederland zijn F. guestfalica Boenn. ex Reichenb., F. ovina L. subsp. ophioliticola (Kerguelen) M.J. Wilkinson, F. lemanii Bast. en F. brevipila Tracey. Onderzoek aan herbariummateriaal (Nationaal Herbarium Nederland te Leiden (L), Natuurmuseum Nijmegen en het herbarium van de auteur) toonde aan dat F. lemanii en F. brevipila in Nederland te onderscheiden zijn. Ook F. psammophila en F. glauca werden in het materiaal aangetoond; het betreft geintroduceerde soorten. Het onderscheid tussen F. brevipila en F. lemanii wordt besproken en toegelicht met een figuur. Wellicht dat ook F. guestfalica in Nederland onderscheiden kan worden, maar hiervoor is meer onderzoek nodig aan de overige taxa van het F. ovina-complex. In the Dutch Floras, Festuca cinerea Vill. encompasses the relatively broad-leaved taxa of the Festuca ovina-complex with long awned lemmas. However, as was shown by Paul Auquier, the real F. cinerea is a species from south-eastern France. Other names which are mentioned in the literature for these broad-leaved sheep-fescues in the Netherlands are F. guestfalica Boenn. ex Reichenb., F. ovina L subsp. ophioliticola (Kerguelen) M.J. Wilkinson, F. lemanii Bast. and F. brevipila Tracey. A morphometrical study revealed the real identity of the Dutch F. cinerea in the collections of the Nationaal Herbarium Nederland at Leiden (L), the herbarium of the Natuurmuseum at Nijmegen and the authors herbarium. From this study, the occurence of F. lemanii Bast. and F. brevipila Tracey could be ascertained. Beside this, also F. psammophila and F. glauca appeared to have been found once, probably as a result of human introduction. An overview of the characteristics of the first two species is given. Some of the studied specimens show a close resemblance to F. guestfalica; however, the true identity of these individuals can only be revealed after a thorough study of the other members of the F. ovina-group (F. ovina and F. filiformis). Festuca brevipila is very common, especially along roadsides and other antropogenous sites, where it has been sown. It remains unclear whether this taxon originally belonged to the Dutch flora. Festuca lemanii is a rather rare taxon wich can be found in dry grasslands (Sedo-Cerastion) along the river system of the Meuse and Rhine Rivers.
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het Festuca ovina complex in nederland 1 f pallens host kalkzwenkgras een veronachtzaamde soort uit zuid limburg
Gorteria, 2005Co-Authors: R HavemanAbstract:Dit artikel vermeldt de ontdekking van Festuca pallens in herbariummateriaal van Nederlandse bodem in de collectie van het Nationaal Herbarium Nederland (NHN) te Leiden. In de eerste helft van de vorige eeuw zijn twee planten van deze soort verzameld in Zuid-Limburg op de Sint Pietersberg en bij Bunde. Het is onbekend of F. pallens nog steeds in Nederland voorkomt aangezien recente collecties ontbreken. De Wilde-Duyfjes rekende de planten, die door de verzamelaars destijds waren gedetermineerd als “F. ovina subsp. eu-ovina var. glauca subvar. pallens”, tot haar ondersoort F. ovina subsp. cinerea (= F. lemanii sensu Flora Europaea p. max. p.). In het voorliggende artikel wordt een beschrijving gegeven van F. pallens en worden de verspreiding en de ecologie van deze soort kort bediscussieerd. The discovery of Dutch specimens of Festuca pallens in the collection of the Nationaal Herbarium Nederland (NHN) in Leiden is reported. In the first half of the last century, two specimens were collected from different places in the western part of South Limburg, Province of Limburg, the Netherlands. It is unknown whether F. pallens still exists in the Netherlands, because more recently collected specimens were not found. The collections were determined as “F. ovina ssp. eu-ovina var. glauca subvar. pallens” by the collectors. De Wilde-Duyfjes considered these plants to belong to her subspecies F. ovina subsp. cinerea (mainly F. lemanii sensu Flora Europaea). A description of F. pallens is given, accompanied with a picture. Furthermore, the distribution and ecology of the species is discussed.
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recente vondsten van genaald schapengras Festuca ovina l op de veluwe
Gorteria, 2003Co-Authors: R Haveman, Marije Van RavensbergAbstract:In the Netherlands, Festuca ovina s. str. (= F. ovina subsp. hirtula) is a very rare taxon, which has often been overlooked. A number of new records is reported from the Veluwe area, all on military ranges, growing in pioneer grasslands (Spergulo-Corynephoretum), dense grasslands on sand (Trifolio-Festucetalia), heathlands (Genisto anglicae-Callunetum), mesophylous fringes (Melampyro-Holcetea), and Scotch Pine forests (LeucobryoPinetum empetretosum).
Zhuo Huang - One of the best experts on this subject based on the ideXlab platform.
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tolerance performance of the cool season turfgrass species Festuca ovina lolium perenne agrostis tenuis and poa trivialis to sulfur dioxide stress
Journal of Plant Interactions, 2015Co-Authors: Huameng Cen, Lingli Peng, Lingxia Sun, Shizhen Cai, Zhuo HuangAbstract:Tolerance of four cool-season turfgrass species sheep fescue (Festuca ovina), perennial ryegrass (Lolium perenne), colonial bentgrass (Agrostis tenuis) and rough bluegrass (Poa trivialis) to SO2 was studied by investigating their injury and physiological responses under SO2 stress for 14 days. Results showed that sheep fescue and perennial ryegrass had better SO2 tolerance than rough bluegrass and colonial bentgrass. Chlorophyll a and carotenoid contents were significantly higher in the SO2-tolerant turfgrass species (sheep fescue and perennial ryegrass) than in the SO2-sensitive turfgrass species (rough bluegrass and colonial bentgrass). Relatively lower levels of reactive oxygen species (ROS), malondialdehyde, and electrolyte leakage (EL) were observed in SO2-tolerant turfgrass species. Gradually increased antioxidant enzyme activities and proline content in SO2-tolerant turfgrass species could counteract such damages and harmful effects caused by ROS and EL, respectively. Sulfite reductase played an im...
Yürüm Yuda - One of the best experts on this subject based on the ideXlab platform.
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Characterization of bio-oils and bio-char obtained from the pyrolysis of a mixture of Lolium perenne, Festuca ovina, Festuca rubra and Poa pratensis grasses
'Informa UK Limited', 2016Co-Authors: Baysal Mustafa, Yürüm YudaAbstract:In this work, the yield and chemical characterization of products obtained from the pyrolysis of a mixture of Lolium perenne, Festuca ovina, Festuca rubra and Poa pratensis grasses under an inert atmosphere at 600 degrees C with a heating rate of 50 degrees C/min was studied. Distribution of the products of pyrolysis grass sample was: moisture: 8 +/- 2%, total volatiles: 78 +/- 7%, char: 14 +/- 5%. Bio-oils were acidic and dark brown liquids and they were separated into oils, asphaltenes and asphaltols by solvent extraction procedures prior to gas chromatography-mass spectrometry (GC-MS) analyses. GC-MS results showed that the bio-oils contained complex mixtures of organic compounds, including acetic acid and a large variety of oxygenated and nitrogenated compounds such as phenols, pyridines, pyrazoles, imidazoles, amines, and ketones. SEM micrographs of the bio-chars indicated amorphous, porous and heterogeneous structure of the bio-char obtained from the grass sample. EDX analysis of the bio-char revealed that bio-char contained K, Ca, P and Mg elements