Andreas Wistuba - Academia.edu (original) (raw)
Papers by Andreas Wistuba
Plant Biology, 2001
Abstract: Nepenthaceae are an exceptional family with regard to carnivory and the uniformity of c... more Abstract: Nepenthaceae are an exceptional family with regard to carnivory and the uniformity of characters. This makes it difficult to resolve phylogenetic relationships due to convergent evolution of morphological features. Using comparative sequencing of the chloroplast trnK intron, the monophyly of this complex family and hypotheses of infrageneric relationships were tested. Sequences from 71 Nepenthes taxa, representing all groups and two taxa of the closely related Ancistrocladaceae and Dioncophyllaceae as outgroup, were determined and analysed using maximum parsimony methods. Results of this analysis show that the isolated taxa N. distillatoria (Sri Lanka) and N. pervillei (Seychelles) are the most basal, clearly separated from the Madagascan taxa N. madagascariensis and N. masoalensis which are placed in a distinct subclade. This corresponds with some plesiomorphic characters shared by these taxa. N. khasiana (North India) has an intermediate position between these relic Western species and the remaining taxa. The species of the Malay Archipelago can be referred to three distinct lineages which indicate a correlation to biogeography. Thus the recent disjunct distribution of Nepenthes is interpreted as a result of an incisive extinction of progenitors, a process of migration and a subsequent diversification on the islands of Borneo, Sumatra, Sulawesi and New Guinea.Based on our molecular data, two interpretations concerning the origin of Nepenthes are possible: i) evolution in the Northern Tethys which is supported by fossil pollen records from the European Focene, or, ii) a Gondwanaland origin at a time when the Indian plate was separated from Madagascar. Molecular data indicate that colonization of SE Asia started from an ancient Indian stock. Subsequently, in the Malay Archipelago a new secondary centre of diversity developed. Madagascar, the Seychelles and New Caledonia were probably reached by migration via land bridges, starting from widespead common ancestors with subsequent extinction leaving the current taxa. There is no evidence for long-distance dispersal. Current infragenic classification of Nepenthes is only partly in accordance with the phylogeny inferred from trnK intron data.
Capsid proteins VP1, VP2 and VP3 of adenoassociated virus type 2 (AAV-2) were separately expresse... more Capsid proteins VP1, VP2 and VP3 of adenoassociated virus type 2 (AAV-2) were separately expressed by recombinant baculoviruses, purified under denaturing conditions and renatured in the presence of 0n5 M arginine, followed by dialysis against buffers of physiological ionic strength. At a protein concentration of 0n05 mg/ml, the three capsid proteins predominantly formed monomers and, to a lesser extent, oligomers, as determined by sedimentation analysis. Oligomerization increased at higher protein concentrations. The capsid protein oligomers consisted of globular, non-capsid-like structures, as detected by electron microscopy. Addition of a HeLa cell extract significantly stimulated oligomerization of the capsid proteins, probably due to interactions with HeLa cell proteins. Characterization of structures sedimenting around 0001-4637 # 1997 SGM BEFD
Adeno-associated virus type 2 (AAV-2) gene expression is tightly controlled by functions of the h... more Adeno-associated virus type 2 (AAV-2) gene expression is tightly controlled by functions of the helper virus as well as by the products of its own viral rep gene. Double-immunofluorescence studies of Rep and VP protein expression in cells coinfected with AAV-2 and adenovirus type 2 showed that a large proportion of these cells expressed Rep78 and Rep52 but no capsid proteins. The percentage of Rep78/Rep52-and capsid proteinpositive cells was strongly influenced by the relative ratio of AAV-2 to adenovirus type 2. In contrast, nearly all cells positive for Rep68/Rep40 were also positive for capsid protein expression. Examination of p40 promoter transactivation by individual Rep proteins in the presence of adenovirus, however, showed that both Rep78 and Rep68 efficiently stimulated p40 mRNA accumulation and capsid protein expression. This strong transactivation was reliant upon the presence of terminal repeats and correlated with template amplification. In replication-deficient expression constructs, transactivation was observed only with Rep68 and was dependent on the linear Rep binding site within the left terminal repeat which was detected in the presence of high adenovirus concentrations. In the absence of any terminal repeat sequences, Rep68 expression again led to a minor transactivation of capsid protein expression which was detectable only at low adenovirus concentrations. This low level of transactivation of capsid protein expression by Rep proteins in the absence of terminal repeats resulted in a lower efficiency of capsid assembly.
The proteins encoded by the adeno-associated virus type 2 (AAV-2) rep and cap genes obtained duri... more The proteins encoded by the adeno-associated virus type 2 (AAV-2) rep and cap genes obtained during a productive infection of HeLa cells with AAV-2 and adenovirus type 2 were fractionated according to solubility, cellular localization, and sedimentation properties. The majority of Rep and Cap proteins accumulated in the nucleus, where they distributed into a soluble and an insoluble fraction. Analysis of the soluble nuclear fraction of capsid proteins by sucrose density gradients showed that they formed at least three steady-state pools: a monomer pool sedimenting at about 6S, a pool of oligomeric intermediates sedimenting between 10 and 15S, and a broad pool of assembly products with a peak between 60 and 110S, the known sedimentation positions of empty and full capsids. While the soluble nuclear monomer and oligomer pool contained predominantly only two capsid proteins, the 30 to 180S assembly products contained VP1, VP2, and VP3 in a stoichiometry similar to that of purified virions. They probably represent different intermediates in capsid assembly, DNA encapsidation, and capsid maturation. In contrast, the cytoplasmic fraction of capsid proteins showed a pattern of oligomers continuously increasing in size without a defined peak, suggesting that assembly of 60S particles occurs in the nucleus. Soluble nuclear Rep proteins were distributed over the whole sedimentation range, probably as a result of association with AAV DNA. Subfractions of the Rep proteins with defined sedimentation values were obtained in the soluble nuclear and cytoplasmic fractions. We were able to coimmunoprecipitate capsid proteins sedimenting between 60 and 110S with antibodies against Rep proteins, suggesting that they exist in common complexes possibly involved in AAV DNA packaging. Antibodies against the capsid proteins, however, precipitated Rep78 and Rep68 predominantly with a peak around 30S representing a second complex containing Rep and Cap proteins.
Using immunofluorescence and in situ hybridization techniques, we studied the intracellular local... more Using immunofluorescence and in situ hybridization techniques, we studied the intracellular localization of adeno-associated virus type 2 (AAV-2) Rep proteins, VP proteins, and DNA during the course of an AAV-2/ adenovirus type 2 coinfection. In an early stage, the Rep proteins showed a punctate distribution pattern over the nuclei of infected cells, reminiscent of replication foci. At this stage, no capsid proteins were detectable. At later stages, the Rep proteins were distributed more homogeneously over the nuclear interior and finally became redistributed into clusters slightly enriched at the nuclear periphery. During an intermediate stage, they also appeared at an interior part of the nucleolus for a short period, whereas most of the time the nucleoli were Rep negative. AAV-2 DNA colocalized with the Rep proteins. All three capsid proteins were strongly enriched in the nucleolus in a transient stage of infection, when the Rep proteins homogeneously filled the nucleoplasm. Thereafter, they became distributed over the whole nucleus and colocalized in nucleoplasmic clusters with the Rep proteins and AAV-2 DNA. While VP1 and VP2 strongly accumulated in the nucleus, VP3 was almost equally distributed between the nucleus and cytoplasm. Capsids, visualized by a conformationspecific antibody, were first detectable in the nucleoli and then spread over the whole nucleoplasm. This suggests that nucleolar components are involved in initiation of capsid assembly whereas DNA packaging occurs in the nucleoplasm. Expression of a transfected full-length AAV-2 genome followed by adenovirus infection showed all stages of an AAV-2/adenovirus coinfection, whereas after expression of the cap gene alone, capsids were restricted to the nucleoli and did not follow the nuclear redistribution observed in the presence of the whole AAV-2 genome. Coexpression of Rep proteins released the restriction of capsids to the nucleolus, suggesting that the Rep proteins are involved in nuclear redistribution of AAV capsids during viral infection. Capsid formation was dependent on the concentration of expressed capsid protein.
Plants, 2014
Together with the islands of Sumatra (Indonesia) and Borneo (Indonesia, Malaysia), the Philippine... more Together with the islands of Sumatra (Indonesia) and Borneo (Indonesia, Malaysia), the Philippines are the main center of diversity for carnivorous pitcher plants of the genus, Nepenthes L. Nepenthes are the largest of all carnivorous plants, and the species with the biggest pitchers are capable of trapping and digesting small amphibians and even mammals. The central cordillera of Mindanao Island in the south of the Philippines is mostly covered with old, primary forest and is the largest remaining cohesive, untouched area of wilderness in the Philippines. In a recent field exploration of two areas of the central cordillera, namely Mount Sumagaya and a section of the Pantaron range, four new taxa of Nepenthes were discovered. These four remarkable new species, N. pantaronensis, N. cornuta, N. talaandig and N. amabilis, are described, illustrated and assessed.
Willdenowia, 2009
Fleischmann A., Wistuba A. & Nerz J.: Three new species of Heliamphora (Sarraceniaceae) f... more Fleischmann A., Wistuba A. & Nerz J.: Three new species of Heliamphora (Sarraceniaceae) from the Guayana Highlands of Venezuela. Willdenowia 39: 273283. Online ISSN 1868-6397; © 2009 BGBM Berlin-Dahlem. doi:10.3372/wi.39.39206 (available via ...
Willdenowia, 2007
Page 1. Willdenowia 37 - 2007 551 ANDREAS FLEISCHMANN, ANDREAS WISTUBA & STEWART MCPHERSON Dr... more Page 1. Willdenowia 37 - 2007 551 ANDREAS FLEISCHMANN, ANDREAS WISTUBA & STEWART MCPHERSON Drosera solaris (Droseraceae), a new sundew from the Guayana High lands Abstract Fleischmann, A., Wistuba ...
Fleischmann, A., Wistuba, A. & McPherson, S.: Drosera solaris (Droseraceae), a new sundew from th... more Fleischmann, A., Wistuba, A. & McPherson, S.: Drosera solaris (Droseraceae), a new sundew from the Guayana Highlands. -Willdenowia 37: 551-555. -ISSN 0511-9618; © 2007 BGBM Berlin-Dahlem. doi:10.3372/wi.37.37214 (available via http://dx.doi.org/)
Willdenowia, 2007
Page 1. Willdenowia 37 - 2007 551 ANDREAS FLEISCHMANN, ANDREAS WISTUBA & STEWART MCPHERSON Dr... more Page 1. Willdenowia 37 - 2007 551 ANDREAS FLEISCHMANN, ANDREAS WISTUBA & STEWART MCPHERSON Drosera solaris (Droseraceae), a new sundew from the Guayana High lands Abstract Fleischmann, A., Wistuba ...
Willdenowia, 2009
Fleischmann A., Wistuba A. & Nerz J.: Three new species of Heliamphora (Sarraceniaceae) f... more Fleischmann A., Wistuba A. & Nerz J.: Three new species of Heliamphora (Sarraceniaceae) from the Guayana Highlands of Venezuela. Willdenowia 39: 273283. Online ISSN 1868-6397; © 2009 BGBM Berlin-Dahlem. doi:10.3372/wi.39.39206 (available via ...
Blumea - Biodiversity, Evolution and Biogeography of Plants, 2007
Nepenthes flava Wistuba, nerz & A. Fleischm. is described as a new species from northern suma... more Nepenthes flava Wistuba, nerz & A. Fleischm. is described as a new species from northern sumatra. it is described and illustrated, including a comparison with the supposed relatives N. inermis danser, N. ovata nerz & Wistuba and N. jacquelineae c. clarke, troy davis & ...
Acta Botanica Gallica, 2005
Plant Biology, 2001
Abstract: Nepenthaceae are an exceptional family with regard to carnivory and the uniformity of c... more Abstract: Nepenthaceae are an exceptional family with regard to carnivory and the uniformity of characters. This makes it difficult to resolve phylogenetic relationships due to convergent evolution of morphological features. Using comparative sequencing of the chloroplast trnK intron, the monophyly of this complex family and hypotheses of infrageneric relationships were tested. Sequences from 71 Nepenthes taxa, representing all groups and two taxa of the closely related Ancistrocladaceae and Dioncophyllaceae as outgroup, were determined and analysed using maximum parsimony methods. Results of this analysis show that the isolated taxa N. distillatoria (Sri Lanka) and N. pervillei (Seychelles) are the most basal, clearly separated from the Madagascan taxa N. madagascariensis and N. masoalensis which are placed in a distinct subclade. This corresponds with some plesiomorphic characters shared by these taxa. N. khasiana (North India) has an intermediate position between these relic Western species and the remaining taxa. The species of the Malay Archipelago can be referred to three distinct lineages which indicate a correlation to biogeography. Thus the recent disjunct distribution of Nepenthes is interpreted as a result of an incisive extinction of progenitors, a process of migration and a subsequent diversification on the islands of Borneo, Sumatra, Sulawesi and New Guinea.Based on our molecular data, two interpretations concerning the origin of Nepenthes are possible: i) evolution in the Northern Tethys which is supported by fossil pollen records from the European Focene, or, ii) a Gondwanaland origin at a time when the Indian plate was separated from Madagascar. Molecular data indicate that colonization of SE Asia started from an ancient Indian stock. Subsequently, in the Malay Archipelago a new secondary centre of diversity developed. Madagascar, the Seychelles and New Caledonia were probably reached by migration via land bridges, starting from widespead common ancestors with subsequent extinction leaving the current taxa. There is no evidence for long-distance dispersal. Current infragenic classification of Nepenthes is only partly in accordance with the phylogeny inferred from trnK intron data.
Capsid proteins VP1, VP2 and VP3 of adenoassociated virus type 2 (AAV-2) were separately expresse... more Capsid proteins VP1, VP2 and VP3 of adenoassociated virus type 2 (AAV-2) were separately expressed by recombinant baculoviruses, purified under denaturing conditions and renatured in the presence of 0n5 M arginine, followed by dialysis against buffers of physiological ionic strength. At a protein concentration of 0n05 mg/ml, the three capsid proteins predominantly formed monomers and, to a lesser extent, oligomers, as determined by sedimentation analysis. Oligomerization increased at higher protein concentrations. The capsid protein oligomers consisted of globular, non-capsid-like structures, as detected by electron microscopy. Addition of a HeLa cell extract significantly stimulated oligomerization of the capsid proteins, probably due to interactions with HeLa cell proteins. Characterization of structures sedimenting around 0001-4637 # 1997 SGM BEFD
Adeno-associated virus type 2 (AAV-2) gene expression is tightly controlled by functions of the h... more Adeno-associated virus type 2 (AAV-2) gene expression is tightly controlled by functions of the helper virus as well as by the products of its own viral rep gene. Double-immunofluorescence studies of Rep and VP protein expression in cells coinfected with AAV-2 and adenovirus type 2 showed that a large proportion of these cells expressed Rep78 and Rep52 but no capsid proteins. The percentage of Rep78/Rep52-and capsid proteinpositive cells was strongly influenced by the relative ratio of AAV-2 to adenovirus type 2. In contrast, nearly all cells positive for Rep68/Rep40 were also positive for capsid protein expression. Examination of p40 promoter transactivation by individual Rep proteins in the presence of adenovirus, however, showed that both Rep78 and Rep68 efficiently stimulated p40 mRNA accumulation and capsid protein expression. This strong transactivation was reliant upon the presence of terminal repeats and correlated with template amplification. In replication-deficient expression constructs, transactivation was observed only with Rep68 and was dependent on the linear Rep binding site within the left terminal repeat which was detected in the presence of high adenovirus concentrations. In the absence of any terminal repeat sequences, Rep68 expression again led to a minor transactivation of capsid protein expression which was detectable only at low adenovirus concentrations. This low level of transactivation of capsid protein expression by Rep proteins in the absence of terminal repeats resulted in a lower efficiency of capsid assembly.
The proteins encoded by the adeno-associated virus type 2 (AAV-2) rep and cap genes obtained duri... more The proteins encoded by the adeno-associated virus type 2 (AAV-2) rep and cap genes obtained during a productive infection of HeLa cells with AAV-2 and adenovirus type 2 were fractionated according to solubility, cellular localization, and sedimentation properties. The majority of Rep and Cap proteins accumulated in the nucleus, where they distributed into a soluble and an insoluble fraction. Analysis of the soluble nuclear fraction of capsid proteins by sucrose density gradients showed that they formed at least three steady-state pools: a monomer pool sedimenting at about 6S, a pool of oligomeric intermediates sedimenting between 10 and 15S, and a broad pool of assembly products with a peak between 60 and 110S, the known sedimentation positions of empty and full capsids. While the soluble nuclear monomer and oligomer pool contained predominantly only two capsid proteins, the 30 to 180S assembly products contained VP1, VP2, and VP3 in a stoichiometry similar to that of purified virions. They probably represent different intermediates in capsid assembly, DNA encapsidation, and capsid maturation. In contrast, the cytoplasmic fraction of capsid proteins showed a pattern of oligomers continuously increasing in size without a defined peak, suggesting that assembly of 60S particles occurs in the nucleus. Soluble nuclear Rep proteins were distributed over the whole sedimentation range, probably as a result of association with AAV DNA. Subfractions of the Rep proteins with defined sedimentation values were obtained in the soluble nuclear and cytoplasmic fractions. We were able to coimmunoprecipitate capsid proteins sedimenting between 60 and 110S with antibodies against Rep proteins, suggesting that they exist in common complexes possibly involved in AAV DNA packaging. Antibodies against the capsid proteins, however, precipitated Rep78 and Rep68 predominantly with a peak around 30S representing a second complex containing Rep and Cap proteins.
Using immunofluorescence and in situ hybridization techniques, we studied the intracellular local... more Using immunofluorescence and in situ hybridization techniques, we studied the intracellular localization of adeno-associated virus type 2 (AAV-2) Rep proteins, VP proteins, and DNA during the course of an AAV-2/ adenovirus type 2 coinfection. In an early stage, the Rep proteins showed a punctate distribution pattern over the nuclei of infected cells, reminiscent of replication foci. At this stage, no capsid proteins were detectable. At later stages, the Rep proteins were distributed more homogeneously over the nuclear interior and finally became redistributed into clusters slightly enriched at the nuclear periphery. During an intermediate stage, they also appeared at an interior part of the nucleolus for a short period, whereas most of the time the nucleoli were Rep negative. AAV-2 DNA colocalized with the Rep proteins. All three capsid proteins were strongly enriched in the nucleolus in a transient stage of infection, when the Rep proteins homogeneously filled the nucleoplasm. Thereafter, they became distributed over the whole nucleus and colocalized in nucleoplasmic clusters with the Rep proteins and AAV-2 DNA. While VP1 and VP2 strongly accumulated in the nucleus, VP3 was almost equally distributed between the nucleus and cytoplasm. Capsids, visualized by a conformationspecific antibody, were first detectable in the nucleoli and then spread over the whole nucleoplasm. This suggests that nucleolar components are involved in initiation of capsid assembly whereas DNA packaging occurs in the nucleoplasm. Expression of a transfected full-length AAV-2 genome followed by adenovirus infection showed all stages of an AAV-2/adenovirus coinfection, whereas after expression of the cap gene alone, capsids were restricted to the nucleoli and did not follow the nuclear redistribution observed in the presence of the whole AAV-2 genome. Coexpression of Rep proteins released the restriction of capsids to the nucleolus, suggesting that the Rep proteins are involved in nuclear redistribution of AAV capsids during viral infection. Capsid formation was dependent on the concentration of expressed capsid protein.
Plants, 2014
Together with the islands of Sumatra (Indonesia) and Borneo (Indonesia, Malaysia), the Philippine... more Together with the islands of Sumatra (Indonesia) and Borneo (Indonesia, Malaysia), the Philippines are the main center of diversity for carnivorous pitcher plants of the genus, Nepenthes L. Nepenthes are the largest of all carnivorous plants, and the species with the biggest pitchers are capable of trapping and digesting small amphibians and even mammals. The central cordillera of Mindanao Island in the south of the Philippines is mostly covered with old, primary forest and is the largest remaining cohesive, untouched area of wilderness in the Philippines. In a recent field exploration of two areas of the central cordillera, namely Mount Sumagaya and a section of the Pantaron range, four new taxa of Nepenthes were discovered. These four remarkable new species, N. pantaronensis, N. cornuta, N. talaandig and N. amabilis, are described, illustrated and assessed.
Willdenowia, 2009
Fleischmann A., Wistuba A. & Nerz J.: Three new species of Heliamphora (Sarraceniaceae) f... more Fleischmann A., Wistuba A. & Nerz J.: Three new species of Heliamphora (Sarraceniaceae) from the Guayana Highlands of Venezuela. Willdenowia 39: 273283. Online ISSN 1868-6397; © 2009 BGBM Berlin-Dahlem. doi:10.3372/wi.39.39206 (available via ...
Willdenowia, 2007
Page 1. Willdenowia 37 - 2007 551 ANDREAS FLEISCHMANN, ANDREAS WISTUBA & STEWART MCPHERSON Dr... more Page 1. Willdenowia 37 - 2007 551 ANDREAS FLEISCHMANN, ANDREAS WISTUBA & STEWART MCPHERSON Drosera solaris (Droseraceae), a new sundew from the Guayana High lands Abstract Fleischmann, A., Wistuba ...
Fleischmann, A., Wistuba, A. & McPherson, S.: Drosera solaris (Droseraceae), a new sundew from th... more Fleischmann, A., Wistuba, A. & McPherson, S.: Drosera solaris (Droseraceae), a new sundew from the Guayana Highlands. -Willdenowia 37: 551-555. -ISSN 0511-9618; © 2007 BGBM Berlin-Dahlem. doi:10.3372/wi.37.37214 (available via http://dx.doi.org/)
Willdenowia, 2007
Page 1. Willdenowia 37 - 2007 551 ANDREAS FLEISCHMANN, ANDREAS WISTUBA & STEWART MCPHERSON Dr... more Page 1. Willdenowia 37 - 2007 551 ANDREAS FLEISCHMANN, ANDREAS WISTUBA & STEWART MCPHERSON Drosera solaris (Droseraceae), a new sundew from the Guayana High lands Abstract Fleischmann, A., Wistuba ...
Willdenowia, 2009
Fleischmann A., Wistuba A. & Nerz J.: Three new species of Heliamphora (Sarraceniaceae) f... more Fleischmann A., Wistuba A. & Nerz J.: Three new species of Heliamphora (Sarraceniaceae) from the Guayana Highlands of Venezuela. Willdenowia 39: 273283. Online ISSN 1868-6397; © 2009 BGBM Berlin-Dahlem. doi:10.3372/wi.39.39206 (available via ...
Blumea - Biodiversity, Evolution and Biogeography of Plants, 2007
Nepenthes flava Wistuba, nerz & A. Fleischm. is described as a new species from northern suma... more Nepenthes flava Wistuba, nerz & A. Fleischm. is described as a new species from northern sumatra. it is described and illustrated, including a comparison with the supposed relatives N. inermis danser, N. ovata nerz & Wistuba and N. jacquelineae c. clarke, troy davis & ...
Acta Botanica Gallica, 2005