The Experts below are selected from a list of 30849 Experts worldwide ranked by ideXlab platform

Zoltan Varga - One of the best experts on this subject based on the ideXlab platform.

  • the genetic structure of phenologically differentiated large blue maculinea arion populations lepidoptera lycaenidae in the carpathian basin
    European Journal of Endocrinology, 2011
    Co-Authors: Judit Bereczki, Janos P Toth, Andrea Toth, Edit Batori, Katalin Pecsenye, Zoltan Varga
    Abstract:

    The infraspecific taxonomy of the European populations of the Large Blue (Maculinea arion) is confusing. Several sub- species have been described mostly based on external morphological features. In the Carpathian Basin two subspecies have been dis- tinguished. Maculinea arion arion flies from mid-May to mid-June and Maculinea arion ligurica is on the wing from the end of June to mid-August. The two forms show some differentiation in habitat use, but occasionally can also share habitats with two peaks in the appearance of butterflies. Our aim was to study the level and structure of genetic variation in a set of populations of the two phe- nologically different M. arion. Imagos were collected from 8 localities between 2000 and 2006. Enzyme Polymorphism was ana- lysed at 13 Enzyme loci using polyacrylamide gel electrophoresis. In the analysis of the data, we estimated the parameters of Polymorphism. To study the pattern of genetic differentiation F-statistics, hierarchical F-statistics and AMOVA were computed. GeneClass and Structure were both applied to analyse the differentiation between the two phenologically different sets of popula- tions. Cavalli-Sforza and Edwards' arc distances were calculated and a UPGMA dendrogram was constructed on the basis of the dis- tance matrix. PCA analysis was also carried out using the allele frequencies of the individuals. The level of Polymorphism was relatively high in M. arion. The results of all analyses indicated that the differences between the two sets of phenologically different populations accounted for a low percentage of the total differentiation. In addition, a sizeable amount of variation could be attributed to the differences among the samples collected from the same population in consecutive years. Thus, we concluded that the "spring" and "summer arion" could not be considered as separate ESUs, although we could attribute conservation value to both forms on the basis of their phenological differentiation and habitat use.

  • genetic differentiation among the maculinea species lepidoptera lycaenidae in eastern central europe
    Biological Journal of The Linnean Society, 2007
    Co-Authors: Katalin Pecsenye, Judit Bereczki, Andrea Toth, Borbala Tihanyi, Laszlo Peregovits, Zoltan Varga
    Abstract:

    The present study aimed to analyse the level of genetic variation in the eastern Central European (Slovenia, Hungary, and Romania/Transylvania) populations of the Large Blues (Maculinea) to analyse the pattern of differentiation both between and within the species. One objective was to compare the level of differentiation between the two disputed species (Maculinea alcon and Maculinea rebeli) with that among the other species. Imagos were collected from 23 localities in eastern Central Europe in 2002. Enzyme Polymorphism was analysed using polyacrylamide gel electrophoresis. Fourteen Enzyme loci were studied in all samples. In the analysis of the data, F-statistics and Nei’s genetic distances were calculated and a dendrogram (unweighted pair group method with arithmetic mean) was constructed on the basis of the distance matrix. A multivariate analysis of variance was performed to study the pattern of genetic differentiation among the samples. Principal component analysis analysis was also carried out using the allele frequency data of the samples. Our results indicated that the large blues are generally less polymorphic than other European lycaenid butterflies studied. At the same time, the level of genetic differentiation was high, even among local populations within the species. A low level of genetic variation within the populations coupled with strong differentiation among them implies the effect of genetic drift. Strong genetic differentiation of four Maculinea species (M. alcon, Maculinea teleius, Maculinea nausithous, and Maculinea arion) was confirmed. Significant differentiation was not found between M. alcon and M. rebeli. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 91, 11–21.

  • pattern of genetic differentiation in the maculinea alcon species group lepidoptera lycaenidae in central europe
    Journal of Zoological Systematics and Evolutionary Research, 2005
    Co-Authors: Judit Bereczki, Katalin Pecsenye, Laszlo Peregovits, Zoltan Varga
    Abstract:

    The taxonomic status of Alcon Blues living in Central and Western Europe (conventionally: Maculinea alcon and Maculinea rebeli) is quite confused. Some authors distinguish them as separate species of the M. alcon species group, while others consider them as subspecies or simply ecological forms. Our aim was to study the pattern of genetic differentiation among several populations of these taxa with reference to their taxonomic position. Imagoes were collected from 27 localities in Central Europe between 1999 and 2003. Samples originated from four regions: northern Hungary, central Hungary, Romania: Transylvania and Slovenia. Enzyme Polymorphism was analysed using polyacrylamide gel electrophoresis. In all samples 16 Enzyme loci were studied. In the analysis of the data, F-statistics was computed and the total genetic variation was partitioned into within and between population components. Nei's genetic distances were calculated and UPGMA dendrogram was constructed on the basis of the distance matrix. Hierarchical F-statistics and amova was computed to study the pattern of genetic differentiation among the samples. Principal component analysis (PCA) was also carried out using the allele frequencies of the samples. The results of all analyses indicated a high level of differentiation among the samples. The differences among the samples collected in different years from the same population accounted for a considerable amount of the between sample variation. The distribution of the between sample variation did not exhibit a species pattern. The results of amova and PCA indicated that the geographic pattern was slightly more expressed in the between sample variation compared with the species pattern of it. These results seem to contradict with the conventional taxonomical subdivision. Zusammenfassung Die taxonomische Unterteilung der zentral- und westeuropaischen Fleckenblaulinge aus der Maculinea alcon-Gruppe (konventionelle Artbezeichnungen: Maculinea alcon und M. rebeli) ist umstritten. Die meisten Autoren unterscheiden zwei getrennte Arten, andere bezeichnen diese jedoch nur als Subspezies oder okologische Rassen einer Spezies. Unser Ziel war es, die genetischen Differenzierungsmuster in mehreren Populationen dieser Taxa zu analysieren und mit der taxonomischen Zuordnung in Bezug zu setzen. Die Schmetterlinge wurden in in den Jahren 1999–2003 an 27 Fangplatzen im sudostlichen Mitteleuropa gesammelt. Diese lassen sich in vier Grosregionen einteilen: Nordungarn (Mittelgebirge), Zentralungarn (Tiefebene und Transdanubisches Mittelgebirge), Rumanien (Siebenburgen) und Slovenien (Kamniker Alpen und slovenisches Karstgebiet). Die Allozymvariation an 16 Enzymloci wurde mittels Polyacrylamid-Gel-Elektrophorese bestimmt. Mittels F-Statistik wurde die gesamte genetische Variation in die Komponenten innerhalb der Populationen bzw. zwischen den Populationen zerteilt. Nei's genetische Distanzen wurden berechnet und aufgrund der Distanzmatrix ein UPGMA-Dendrogramm konstruiert. Die genetische Differenzierung der Populationen wurde mittels hierarchische F-Statistik und amova bestimmt, weiters wurde eine PCA-Analyse auf Basis der Allelhaufigkeiten durchgefuhrt. Samtliche Ergebnisse dieser Analysen weisen auf eine hochgradige Differenzierung zwischen den Populationsstichproben hin. Ausgepragte Unterschiede finden sich auch zwischen den verschiedenen Jahrgangen der einzelnen Populationen. Das Verteilungsmuster der Unterschiede zwischen den untersuchten Populationen ergab keinen Hinweis auf eine genetische Differenzierung der Arten. Die Ergebnisse von amova und PCA zeigten, dass die Differenzierung zwischen den Populationen etwas starker ist als jene zwischen den Arten.

Tracy E Hunley - One of the best experts on this subject based on the ideXlab platform.

  • angiotensin converting Enzyme gene Polymorphism potential silencer motif and impact on progression in iga nephropathy
    Kidney International, 1996
    Co-Authors: Tracy E Hunley, Bruce A Julian, John A Phillips, Marshall L Summar
    Abstract:

    Angiotensin converting gene Enzyme Polymorphism: Potential silencer motif and impact on progression in IgA nephropathy. Since the renin angiotensin system (RAS) is established as an important factor in renal disease progression, we determined whether RAS alleles that have been linked to variability in outcome in several cardiovascular diseases also affect progression of IgA nephropathy. These genetic variants include: (1) angiotensin I converting Enzyme deletion Polymorphism in intron 16 (ACE I/D), reported to be associated with increased risk of myocardial infarction as well as left ventricular hypertrophy; (2) a point mutation in the angiotensinogen (Agt) gene resulting in a methionine to threonine substitution at residue 235 (M235T), reported to be associated with hypertension in Caucasians; and (3) an angiotensin receptor type I (ATR) A to C transition at bp 1166 (A1166C) which shows synergy with the deleterious effects of the ACE DD genotype in myocardial infarction. We examined these Polymorphisms by PCR amplification of genomic DNA samples from 64 Caucasian patients in the USA (age 6 to 83 years) with biopsy-proven IgA nephropathy whose renal status was followed for an average of almost seven years. Patients who presented with and maintained normal serum creatinine (Cr,

James H Marden - One of the best experts on this subject based on the ideXlab platform.

  • Enzyme Polymorphism oxygen and injury a lipidomic analysis of flight induced oxidative damage in a succinate dehydrogenase d sdhd polymorphic insect
    The Journal of Experimental Biology, 2018
    Co-Authors: Julianne E Pekny, Philip B Smith, James H Marden
    Abstract:

    ABSTRACT When active tissues receive insufficient oxygen to meet metabolic demand, succinate accumulates and has two fundamental effects: it causes ischemia–reperfusion injury while also activating the hypoxia-inducible factor pathway (HIF). The Glanville fritillary butterfly ( Melitaea cinxia ) possesses a balanced Polymorphism in Sdhd , shown previously to affect HIF pathway activation and tracheal morphology and used here to experimentally test the hypothesis that variation in succinate dehydrogenase affects oxidative injury . We stimulated butterflies to fly continuously in a respirometer (3 min duration), which typically caused episodes of exhaustion and recovery, suggesting a potential for cellular injury from hypoxia and reoxygenation in flight muscles. Indeed, flight muscle from butterflies flown on consecutive days had lipidome profiles similar to those of rested paraquat-injected butterflies, but distinct from those of rested untreated butterflies. Many butterflies showed a decline in flight metabolic rate (FMR) on day 2, and there was a strong inverse relationship between the ratio of day 2 to day 1 FMR and the abundance of sodiated adducts of phosphatidylcholines and co-Enzyme Q (CoQ). This result is consistent with elevation of sodiated lipids caused by disrupted intracellular ion homeostasis in mammalian tissues after hypoxia–reperfusion. Butterflies carrying the Sdhd M allele had a higher abundance of lipid markers of cellular damage, but the association was reversed in field-collected butterflies, where focal individuals typically flew for seconds at a time rather than continuously. These results indicate that Glanville fritillary flight muscles can be injured by episodes of high exertion, but injury severity appears to be determined by an interaction between SDH genotype and behavior (prolonged versus intermittent flight).

John A Phillips - One of the best experts on this subject based on the ideXlab platform.

  • angiotensin converting Enzyme gene Polymorphism potential silencer motif and impact on progression in iga nephropathy
    Kidney International, 1996
    Co-Authors: Tracy E Hunley, Bruce A Julian, John A Phillips, Marshall L Summar
    Abstract:

    Angiotensin converting gene Enzyme Polymorphism: Potential silencer motif and impact on progression in IgA nephropathy. Since the renin angiotensin system (RAS) is established as an important factor in renal disease progression, we determined whether RAS alleles that have been linked to variability in outcome in several cardiovascular diseases also affect progression of IgA nephropathy. These genetic variants include: (1) angiotensin I converting Enzyme deletion Polymorphism in intron 16 (ACE I/D), reported to be associated with increased risk of myocardial infarction as well as left ventricular hypertrophy; (2) a point mutation in the angiotensinogen (Agt) gene resulting in a methionine to threonine substitution at residue 235 (M235T), reported to be associated with hypertension in Caucasians; and (3) an angiotensin receptor type I (ATR) A to C transition at bp 1166 (A1166C) which shows synergy with the deleterious effects of the ACE DD genotype in myocardial infarction. We examined these Polymorphisms by PCR amplification of genomic DNA samples from 64 Caucasian patients in the USA (age 6 to 83 years) with biopsy-proven IgA nephropathy whose renal status was followed for an average of almost seven years. Patients who presented with and maintained normal serum creatinine (Cr,

Bruce A Julian - One of the best experts on this subject based on the ideXlab platform.

  • angiotensin converting Enzyme gene Polymorphism potential silencer motif and impact on progression in iga nephropathy
    Kidney International, 1996
    Co-Authors: Tracy E Hunley, Bruce A Julian, John A Phillips, Marshall L Summar
    Abstract:

    Angiotensin converting gene Enzyme Polymorphism: Potential silencer motif and impact on progression in IgA nephropathy. Since the renin angiotensin system (RAS) is established as an important factor in renal disease progression, we determined whether RAS alleles that have been linked to variability in outcome in several cardiovascular diseases also affect progression of IgA nephropathy. These genetic variants include: (1) angiotensin I converting Enzyme deletion Polymorphism in intron 16 (ACE I/D), reported to be associated with increased risk of myocardial infarction as well as left ventricular hypertrophy; (2) a point mutation in the angiotensinogen (Agt) gene resulting in a methionine to threonine substitution at residue 235 (M235T), reported to be associated with hypertension in Caucasians; and (3) an angiotensin receptor type I (ATR) A to C transition at bp 1166 (A1166C) which shows synergy with the deleterious effects of the ACE DD genotype in myocardial infarction. We examined these Polymorphisms by PCR amplification of genomic DNA samples from 64 Caucasian patients in the USA (age 6 to 83 years) with biopsy-proven IgA nephropathy whose renal status was followed for an average of almost seven years. Patients who presented with and maintained normal serum creatinine (Cr,