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Christoph Oberprieler - One of the best experts on this subject based on the ideXlab platform.
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Lost in the hybridisation vortex: high-elevation Senecio hercynicus (Compositae, Senecioneae) is genetically swamped by its congener S. Ovatus in the Bavarian Forest National Park (SE Germany)
Evolutionary Ecology, 2017Co-Authors: Claus Bässler, Christoph OberprielerAbstract:Hybridisation is an important evolutionary process. The investigation of hybridisation along elevational gradients, with their steep abiotic and biotic clines, provides insight into the adaptation and maintenance of species in adjacent habitats. The rare Senecio hercynicus and its spreading congener S. Ovatus are vertically vicariant species that show hybridisation in their range overlaps. In the present study, we used AFLP fingerprinting of 689 individuals from 38 populations to analyse population structure and introgression patterns along four elevational transects (650–1350 m) in the Bavarian Forest National Park, Gemany. Subsequently, we searched for loci putatively under divergent selection that may maintain ‘pure’ species despite hybrid formation by identifying taxon-specific alleles. A maximum-likelihood based hybrid index shows that the overall genetic differentiation among all populations was very low with a vanishingly small number of pure parental individuals. Almost 75% of the investigated individuals were classified as backcrosses towards S. Ovatus. The highest S. hercynicus ancestry was found in the uppermost populations of two transects. Further, we found seven taxon-specific alleles being under divergent selection that correlated with climatic variables and deviating from neutral introgression. According to our results, hybridisation of S. Ovatus and S. hercynicus has reached an advanced state of genetic swamping and there seems to be no driving force that is strong enough to keep both species as different lineages. Rather, S. Ovatus appears to benefit through putatively adaptive introgression.
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Phytochemical investigations and food-choice experiments with two mollusc species in three central European Senecio L. (Asteraceae, Senecioneae) species and their hybrids
Chemoecology, 2017Co-Authors: Michael Elmer, Martin Doppel, Hans Friedrich Ehrnsberger, Till Beuerle, Jörg Heilmann, Christoph OberprielerAbstract:Differences in herbivore resistance between parental and hybrid taxa influence the trajectories of hybrid swarms and may lead to the maintenance or breakdown of species boundaries. In the present study, phytochemical patterns in terms of pyrrolizidine alkaloids (PAs) and tannins in three central European representatives of the Senecio nemorensis syngameon (i.e., S. germanicus, S. hercynicus, S. Ovatus ) were inferred and the selective consumption among the pure species and among the pure species and their reciprocal hybrids was studied in food-choice (‘cafeteria’) experiments using two mollusc species. The results show significant qualitative and quantitative differences in chemical composition among the three plant species. Artificial F _ 1 hybrids of the two investigated plant systems S. germanicus – S. Ovatus and S. hercynicus – S. Ovatus mainly expressed an additive PA pattern compared to the parental taxa. PA concentration was highest in S. hercynicus, intermediate in S. Ovatus and lowest in S. germanicus, while tannin concentration was lower in S. hercynicus compared to S. Ovatus and S. germanicus . Food-choice experiments revealed significant plant species-specific preferences exhibited by the two mollusc species (the slug Arion fuscus and the snail Trochulus striolatus danubialis ). Consistent negative correlations between the total PA concentration and the consumed leaf area were only observed for the snail, but not for the slug species. When reciprocal hybrid taxa were added to the food-choice designs, the plant taxon-specific differences in consumption disappeared. Additionally, no significant effect of tannin concentration on strength of herbivory was observed. The present results of food-choice experiments in three representatives of the S. nemorensis syngameon, therefore, demonstrate that PAs rather than tannins influence taxon-specific herbivory by molluscs. However, they also suggest that trajectories of mixed stands and hybrid swarms in the wild could be more pronouncedly determined by the local composition of mollusc communities, the frequency of intermediate chemotypes (hybrids), and other factors (e.g., morphology, other biotic and abiotic conditions).
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Herbivory and fitness components in an introgressive hybrid swarm of Senecio hercynicus and S. Ovatus (Compositae, Senecioneae)
Flora - Morphology Distribution Functional Ecology of Plants, 2016Co-Authors: Christoph Oberprieler, Manuela Bog, Bianca BerchtoldAbstract:Abstract Hybridization among plant species may have considerable evolutionary consequences, from the formation of new taxa to the extinction of species by genetic swamping. The evolutionary fate of a system of hybridizing species is highly dependent on fitness differences between parental and hybrid genotypes. In an introgressed hybrid swarm of the rare Senecio hercynicus and its widely distributed congener Senecio Ovatus (Compositae, Senecioneae) we assessed pollen fertility, seed set, and germination rates, along with leaf damage dynamics due to herbivory throughout the vegetation period of 2006 in order to compare intrinsic and extrinsic fitness components among genotypes. Correlation and linear regression analyses carried out with fitness components as dependent and genetic constitution, phenology, and pyrrolizidine alkaloid (PA) content as independent variables reveal that: (a) intrinsic fitness components (pollen fertility, seed set, germination rate) are not reduced in hybrid and backcross individuals, (b) the extrinsic fitness component of leaf damage caused by herbivores is significantly influenced by genetic constitution ( S. hercynicus- like individuals being more severely damaged than hybrid genotypes and S. Ovatus- like individuals), by phenology (early flowering individuals exhibiting higher damage than late-flowering ones), and PA concentration (with the astonishing result of hercynicus- like genotypes being increasingly damaged by herbivory with increasing PA concentrations and a reversed trend – decreasing damage with increasing PA content – in the hybrid and the Ovatus- like genotypes). When all surveyed fitness parameters are considered in conjunction, the present results nicely demonstrate that hybrid genotypes neither suffer from intrinsic nor from extrinsic fitness reductions and that the rare and early-flowering S. hercynicus is outperformed by hybrids and S. Ovatus- like genotypes. The present study, therefore, adds further support to the prediction that S. hercynicus will be genetically swamped by the spreading S. Ovatus.
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Introgressive hybridization of Senecio hercynicus and S. Ovatus (Compositae, Senecioneae) along an altitudinal gradient in Harz National Park (Germany)
Systematics and Biodiversity, 2007Co-Authors: Dorit Raudnitschka, Isabell Hensen, Christoph OberprielerAbstract:Abstract Introgressive hybridization of Senecio hercynicus and S. Ovatus (Compositae, Senecioneae) was studied in a hybrid zone on the southern slopes of Mt Brocken (Harz Mountains, Germany). A total of 415 plants representing 10 stands along an altitudinal gradient were investigated using multivariate statistical analyses of morphological characters and molecular markers (random amplified polymorphic DNA[RAPD]). Both types of traits detected pure S. hercynicus stands on the summit plateau, pure S. Ovatus stands at the lowest elevations, and hybrid swarms at intermediate elevations. While morphological and molecular patterns coincided, some individuals in hybrid stands combined morphological patterns typical of S. Ovatus with RAPD patterns typical of S. hercynicus, and vice versa. In general, introgression was symmetrical within stands, though one stand combined S. Ovatus characters with the glandular hair typical for S. hercynicus, and two stands combined a S. hercynicus typical RAPD genotype with morpho...
Dianchang Zhang - One of the best experts on this subject based on the ideXlab platform.
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identification of fatty acid desaturase 6 in golden pompano trachinotus Ovatus linnaeus 1758 and its regulation by the pparαb transcription factor
International Journal of Molecular Sciences, 2018Co-Authors: Ke-cheng Zhu, Shigui Jiang, Huayang Guo, Nan Zhang, Liang Guo, Bao-suo Liu, Ling Song, Dianchang ZhangAbstract:Fatty acid desaturases are rate-limiting enzymes in long-chain polyunsaturated fatty acid biosynthesis. The transcription factor peroxisome proliferator-activated receptor alpha b (PPARαb) regulates lipid metabolism in mammals, however, the mechanism whereby PPARαb regulates fatty acid desaturases is largely unknown in fish. In this study, we report the full length cDNA sequence of Trachinotus Ovatus fatty acid desaturase, which encodes a 380 amino acid polypeptide, possessing three characteristic histidine domains. Phylogenetic and gene exon/intron structure analyses showed typical phylogeny: the T. Ovatus fatty acid desaturase contained a highly conserved exon/intron architecture. Moreover, functional characterization by heterologous expression in yeast indicated that T. Ovatus desaturase was a fatty acid desaturase, with Δ4/Δ5/Δ8 Fad activity. Promoter activity assays indicated that ToFads6 desaturase transcription was positively regulated by PPARαb. Similarly, PPARαb RNA interference decreased ToPPARαb and ToFads6 expression at the mRNA and protein levels in a time-dependent manner. Mutation analyses showed that the M2 binding site of PPARαb was functionally important for protein binding, and transcriptional activity of the ToFads6 promoter was significantly decreased after targeted mutation of M2. Electrophoretic mobile shift assays confirmed that PPARαb interacted with the binding site of the ToFads6 promoter region, to regulate ToFads6 transcription. In summary, PPARαb played a vital role in ToFads6 regulation and may promote the biosynthesis of long-chain polyunsaturated fatty acids by regulating ToFads6 expression.
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The polymorphisms of MHCIIß gene of Trachinotus Ovatus and their association with resistance/susceptibility to Photobacterium damsela
Aquaculture, 2018Co-Authors: Ke-cheng Zhu, Huayang Guo, Shigui Jiang, Nan Zhang, Dianchang ZhangAbstract:Abstract Trachinotus Ovatus is an important economic species in China, with an annual output of over 100,000 tons (FAO). The major histocompatibility complex (MHC) genes, which are a highly polymorphic gene superfamily, play a vital role in the adaptive immune system. In our study, due to the threat caused by Photobacterium damselae, the associations between polymorphisms of exon 2 of MHC IIs and disease resistance/susceptibility were analysed in Trachinotus Ovatus. The gene structure of MHC IIs was composed of six exons and five introns in T. Ovatus, similar to Hippocampus erectus MHC IIs. Among the forty-three alleles, high levels of polymorphism were found (24.8% of nucleotide positions were variable). In the peptide-binding region (PBR) and non-PBR sites, the value of dN was 6.60 and 12.22 (> 1) times higher than the value of dS, respectively. Six alleles were chosen to calculate their distributions in the high-resistance (HR) and high-susceptibility (HS) groups. The analysis of the associations between alleles and resistance/susceptibility to P. damselae indicated that the TO-DAB-01 allele was associated with immunity to P. damselae and the TO-DAB-04, TO-DAB-05 and TO-DAB-10 alleles were associated with its sensitivity to P. damselae. The results suggest that the diversity of exon 2 of MHC IIs alleles could be used to explore the association between disease susceptibility/resistance and the multiformity of MHC IIs and to achieve the molecular-assisted selection of T. Ovatus with enhanced disease resistance.
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Genomic structure, expression pattern and polymorphisms of GILT in golden pompano Trachinotus Ovatus (Linnaeus 1758).
Gene, 2018Co-Authors: Ke-cheng Zhu, Shigui Jiang, Huayang Guo, Nan Zhang, Liang Guo, Bao-suo Liu, Dianchang ZhangAbstract:Abstract The interferon-g-inducible lysosomal thiol reductase (GILT) plays a significant character in the processing and presentation of MHC class II restricted antigen (Ag) by catalyzing disulfide bond reduction in mammals. To explore the function of GILT in the immune system of fish, we cloned a GILT gene homologue from Trachinotus Ovatus, the full-length cDNA of GILT, which consisted of 2, 747 bp with a 771 bp open reading frame, encoding a protein of 256 amino acids. Moreover, similar to other species GILT gene, 7 exons and 6 introns were identified in T. Ovatus, the deduced protein also possessed a representative characteristic of known GILT proteins. The result of real-time quantitative PCR showed that GILT mRNA was dramatically expressed in immune-associated tissues, such as spleen (p G) was identified, and the allele C was significantly associated with high-susceptibility (HS) group, nevertheless, the allele G was dramatically associated with high-resistance (HR) group, indicating potential application for disease resistant breeding selection in T. Ovatus.
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Complete mitochondrial genome sequence of golden pompano Trachinotus Ovatus.
Mitochondrial DNA, 2014Co-Authors: Liyuan Sun, Dianchang Zhang, Shigui Jiang, Huayang Guo, Caiyan ZhuAbstract:The complete mitochondrial genome of Trachinotus Ovatus was determined by the polymerase chain reaction (PCR). The mitogenome is 16,564 bp long and has the typical vertebrate mitochondrial gene arrangement, including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and one control region. The overall base composition of mitogenome is estimated to be 29.0% for A, 28.9% for C, 26.2% for T, 15.9% for G, respectively, with a high A + T content (55.2%). With the exception of ND6 and eight tRNA genes, all other mitochondrial genes are encoded on the heavy strand. The control region contains a dinucleotide repeat motif, (AT)5. This mitogenome sequence would play an important role in population genetics and the molecular taxonomy of T. Ovatus.
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Isolation and characterization of 21 polymorphic microstatellites in golden pompano Trachinotus Ovatus
Conservation Genetics Resources, 2013Co-Authors: Liyuan Sun, Dianchang Zhang, Shigui Jiang, Huayang Guo, Caiyan ZhuAbstract:The golden pompano Trachinotus Ovatus is a most important marine fish in South China, and the wild population of T. Ovatus has been rapidly decreasing owing to overfishing recently, to understand the genetic status for the conservation, we isolated and characterized twenty-one polymorphic microsatellites from a (GT)13 enriched genomic library. The number of alleles ranged from 2 to 10. The observed and expected heterozygosities ranged from 0.083 to 0.792 and from 0.081 to 0.886, respectively. The PIC value ranged from 0.0767 to 0.8623. Six loci deviated from Hardy-Weinberg equilibrium. Finally, the 21 novel informative microsatellite markers could be used in future population genetic study of T. Ovatus that might be useful in a context of marine biodiversity conservation.
Iva Hodálová - One of the best experts on this subject based on the ideXlab platform.
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Sympatric populations of Senecio Ovatus subsp. Ovatus, S. germanicus subsp. germanicus (Compositae) and their hybrid in the Carpathians and the adjacent part of Pannonia: II. Synecological differentiation and distribution
Flora, 1996Co-Authors: Iva Hodálová, Milan ValachovičAbstract:Summary A synecological study of two sympatric taxa - S. Ovatus subsp. Ovatus and S. germanicus subsp. germanicus , based on 49 releyes, made during years 1987-1993 in the Carpathians, is presented. Numerical classification (cluster analysis) and ordination (principal components analysis, PCA), were used. Existing published releves obtained from representative phytocoenological tables from the region studied were compared to the results of the numerical classification and ordination. S. germanicus subsp. germanicus was encountered in the whole Carpathians and prefers sunny or semi-shady mesophilous or subxerophilous places (e.g. natural forest fringes) of the submontane and montane belt. S. Ovatus subsp. Ovatus and S. × futakii ( S. germanicus subsp. germanicus × S. Ovatus subsp. Ovatus ) is distributed mainly in the West Carpathians in shady, semi-shady mesophilous or hygrophilous places of the submontane and montane belt.
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Sympatric populations of Senecio Ovatus subsp. Ovatus, S. germanicus subsp. germanicus (Compositae) and their hybrid in the Carpathians and the adjacent part of Pannonia
Flora, 1996Co-Authors: Iva Hodálová, Karol MarholdAbstract:Summary A multivariate morphometric study of Senecio germanicus subsp. germanicus, Senecio Ovatus subsp. Ovatus and their hybrid, Senecio × futakii based on 19 population samples, collected throughout the Carpathians in Slovakia, Ukraine and Romania, is presented. Multivariate methods used include principal components analysis, cluster analysis, classificatory and canonical discriminant analysis. As a complementary evidence, the hybrid indices were calculated. In spite of possible problems in classification of certain plants into “pure” types or hybrids, the existence of parental species and hybrids in the area studied was proven.
Luis Caraballo - One of the best experts on this subject based on the ideXlab platform.
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mite allergy in the tropics sensitization to six domestic mite species in cartagena colombia
Journal of Investigational Allergology and Clinical Immunology, 1993Co-Authors: Leonardo Puerta, Enrique Fernandezcaldas, Richard F. Lockey, Luis CaraballoAbstract:: Sensitization to the domestic mites Blomia tropicalis, Chortoglyphus arcuatus, Lepidoglyphus destructor and Aleuroglyphus Ovatus was investigated in 77 subjects with clinical symptoms of asthma and/or allergic rhinitis and a positive skin prick test (wheal > or = 3 mm) to Dermatophagoides pteronyssinus and/or D. farinae. Seventy patients were skin test-positive to D. pteronyssinus and 73 to D. farinae. Serum samples from 29 nonallergic, skin test-negative individuals were used as negative controls. Specific IgE was determined by RAST and the results expressed as the % of the total counts bound (% TCB). A positive result (> or = 1% TCB) to D. farinae was detected in 89.6% of subjects, to B. tropicalis in 80.5%, to D. pteronyssinus in 75.3%, to C. arcuatus in 71.4%, to A. Ovatus in 68.8% and to L. destructor in 59.7%. None of the controls had a positive RAST to any of the mite species. Different IgE binding patterns were observed among these subjects, suggesting sensitization to unique as well as common allergens in the different mite species. Sensitization to Pyroglyphidae (D. pteronyssinus and D. farinae) and non-Pyroglyphidae mites (B. tropicalis, C. arcuatus, L. destructor and A. Ovatus) is common among allergic individuals in Cartagena. Extracts of these mites may be needed for a more accurate diagnosis and effective treatment of respiratory diseases due to mite allergy in tropical environments.
Karol Marhold - One of the best experts on this subject based on the ideXlab platform.
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Sympatric populations of Senecio Ovatus subsp. Ovatus, S. germanicus subsp. germanicus (Compositae) and their hybrid in the Carpathians and the adjacent part of Pannonia
Flora, 1996Co-Authors: Iva Hodálová, Karol MarholdAbstract:Summary A multivariate morphometric study of Senecio germanicus subsp. germanicus, Senecio Ovatus subsp. Ovatus and their hybrid, Senecio × futakii based on 19 population samples, collected throughout the Carpathians in Slovakia, Ukraine and Romania, is presented. Multivariate methods used include principal components analysis, cluster analysis, classificatory and canonical discriminant analysis. As a complementary evidence, the hybrid indices were calculated. In spite of possible problems in classification of certain plants into “pure” types or hybrids, the existence of parental species and hybrids in the area studied was proven.
