The indication of origin of sesame seeds and sesame oil is one of the important factors influenci... more The indication of origin of sesame seeds and sesame oil is one of the important factors influencing its price, as it is produced in many regions worldwide and certain provenances are especially sought after. We joined stable carbon and hydrogen isotope analysis with DNA based molecular marker analysis to study their combined potential for the discrimination of different origins of sesame seeds. For the stable carbon and hydrogen isotope data a positive correlation between both isotope parameters was observed, indicating a dominant combined influence of climate and water availability. This enabled discrimination between sesame samples from tropical and subtropical/moderate climatic provenances. Carbon isotope values also showed differences between oil from black and white sesame seeds from identical locations, indicating higher water use efficiency of plants producing black seeds. DNA based markers gave independent evidence for geographic variation as well as provided information on ...
Experiments were undertaken to reveal the spontaneous differentiation capacity of the nullipotent... more Experiments were undertaken to reveal the spontaneous differentiation capacity of the nullipotent F9 embryonal-carcinoma (EC) cell line in colonies derived from single cells. Culture conditions which allowed the development of neuroblasts in colonies of the multipotent EC cell line (PCC3) were worked out, and comparative studies on neuroblast differentiation in PCC3 and F9 colonies were conducted. Neural-cell-specific silver impregnation, selective staining of cells having electrically excitable membranes with merocyanine 540 and the observation of nerve processes were considered as differentiation markers. The appearance of neuroblasts in F9 and PCC3 colonies could be detected from the 6th day after seeding. The development of neuroblasts was less prevalent in high-density cultures, especially in the case of F9. By the 8th day in differentiating colonies, PCC3 cells lost much of their colony-forming activity, while F9 cells preserved their original high plating efficiency, in spite of advanced differentiation. The determination of growth parameters during differentiation in colonies led to the conclusion that F9 cells had lost certain growth-control mechanisms which normally restrict the clonal growth of EC cells. It is suggested that the phenomenon of nullipotence may be analysed in terms of the coordinated regulation of proliferation and differentiation of EC cells.
In this study a size selected genomic library from Quercus petraea was screened for (GA/CT)n-micr... more In this study a size selected genomic library from Quercus petraea was screened for (GA/CT)n-microsatellite sequences. The resulting loci were analysed by PCR for their usefulness as molecular markers in Q. petraea and Q. robur. 17 out of 52 tested primer pairs resulted in the amplification of a polymorphic single-locus pattern. The number of alleles found per locus varied from 6 to 16. Combining the genetic variation observed for the characterized loci provides a unique genotype for all the individuals tested. Using intraspecific controlled crosses of Q. robur trees Mendelian inheritance could be shown for five loci.
Proceedings of The National Academy of Sciences, 1991
A 13,863-base-pair (bp) putative centromeric DNA fragment has been isolated from a human genomic ... more A 13,863-base-pair (bp) putative centromeric DNA fragment has been isolated from a human genomic library by using a probe obtained from metaphase chromosomes of human colon carcinoma cells. The abundance of this DNA was estimated to be 16-32 copies per genome. Cotransfection of mouse cells with this sequence and a selectable marker gene (aminoglycoside 3'-phosphotransferase type II, APH-II) resulted in
Oak chloroplast DNA (cpDNA) variation was studied in a grid-based inventory in western Central Eu... more Oak chloroplast DNA (cpDNA) variation was studied in a grid-based inventory in western Central Europe, including Belgium, The Netherlands, Luxembourg, Germany, the Czech Republic, and the northern parts of Upper and Lower Austria. A total of 2155 trees representing 426 populations of Quercus robur L. and Q. petraea (Matt.) Liebl. were screened for polymorphism in up to four PCR-amplified cpDNA
A genetic map of Pedunculate oak (Quercus robur) was constructed based on one 5S rDNA, 271 RAPD, ... more A genetic map of Pedunculate oak (Quercus robur) was constructed based on one 5S rDNA, 271 RAPD, ten SCAR, 18 microsatellite, one minisatellite, and six isozyme markers. A total of 94 individuals from a full-sib family was genotyped. Two maps, including 307 markers, were constructed according to the “two-way pseudo-testcross” mapping strategy. Testcross markers segregating in the 1 : 1 ratio were
Available evidence shows that sweetpotato originated from either Central or South American lowlan... more Available evidence shows that sweetpotato originated from either Central or South American lowlands with subsequent dispersal to North America, Europe, Africa, Asia and the pacific islands. A total of 71 polymorphic RAPD molecular markers were used to assess the genetic relationships amongst 74 sweetpotato varieties originating from a total of 23 sweetpotato producing countries within six geographical regions, namely, South
RNaseH-LTR regions of the Ty1-copia retrotransposon were amplified and cloned from the sweetpotat... more RNaseH-LTR regions of the Ty1-copia retrotransposon were amplified and cloned from the sweetpotato genome using RNaseH gene-specific degenerate primers and restriction site-specific adaptor primers. Ninety clones out of the 240 sequenced were identified with a variable degree of homology to the Ty1-copia RNaseH gene. Three ( Str6, Str85, Str187) of the 90 had characteristic RNaseH-gene, stop codon, polypurine track and putative 3' LTR sequence elements. Analysis of nine selected genotypes representing Africa, South and Central America, as well as Papua New Guinea, by the established S-SAP technique revealed that the majority of the Ty1-copia transposon insertions were unique (33 to 64%) and only few common bands were detected. Analysis of 177 East African varieties further supported this finding and showed that most of the copia retrotransposon locations were represented only by some genotypes. Considering that sweetpotato has been present in the East African region for only about 500 years, and the number of genotypes introduced was possibly limited, a surprisingly high level of genetic variability of the transposon insertion sites was detected. These findings may indicate the putative activity of the retrotransposon in sweetpotato in the recent past. Comparison of the copia retrotransposon insertion-based S-SAP method to AFLP and RAPD showed that the majority of the markers were more polymorphic (97-99%) in the case of S-SAP in comparison to AFLP (70-90%) and RAPD (88%). Thus demonstrating the transposon-based molecular marker system was very efficient for genotyping.
The indication of origin of sesame seeds and sesame oil is one of the important factors influenci... more The indication of origin of sesame seeds and sesame oil is one of the important factors influencing its price, as it is produced in many regions worldwide and certain provenances are especially sought after. We joined stable carbon and hydrogen isotope analysis with DNA based molecular marker analysis to study their combined potential for the discrimination of different origins of sesame seeds. For the stable carbon and hydrogen isotope data a positive correlation between both isotope parameters was observed, indicating a dominant combined influence of climate and water availability. This enabled discrimination between sesame samples from tropical and subtropical/moderate climatic provenances. Carbon isotope values also showed differences between oil from black and white sesame seeds from identical locations, indicating higher water use efficiency of plants producing black seeds. DNA based markers gave independent evidence for geographic variation as well as provided information on ...
Experiments were undertaken to reveal the spontaneous differentiation capacity of the nullipotent... more Experiments were undertaken to reveal the spontaneous differentiation capacity of the nullipotent F9 embryonal-carcinoma (EC) cell line in colonies derived from single cells. Culture conditions which allowed the development of neuroblasts in colonies of the multipotent EC cell line (PCC3) were worked out, and comparative studies on neuroblast differentiation in PCC3 and F9 colonies were conducted. Neural-cell-specific silver impregnation, selective staining of cells having electrically excitable membranes with merocyanine 540 and the observation of nerve processes were considered as differentiation markers. The appearance of neuroblasts in F9 and PCC3 colonies could be detected from the 6th day after seeding. The development of neuroblasts was less prevalent in high-density cultures, especially in the case of F9. By the 8th day in differentiating colonies, PCC3 cells lost much of their colony-forming activity, while F9 cells preserved their original high plating efficiency, in spite of advanced differentiation. The determination of growth parameters during differentiation in colonies led to the conclusion that F9 cells had lost certain growth-control mechanisms which normally restrict the clonal growth of EC cells. It is suggested that the phenomenon of nullipotence may be analysed in terms of the coordinated regulation of proliferation and differentiation of EC cells.
In this study a size selected genomic library from Quercus petraea was screened for (GA/CT)n-micr... more In this study a size selected genomic library from Quercus petraea was screened for (GA/CT)n-microsatellite sequences. The resulting loci were analysed by PCR for their usefulness as molecular markers in Q. petraea and Q. robur. 17 out of 52 tested primer pairs resulted in the amplification of a polymorphic single-locus pattern. The number of alleles found per locus varied from 6 to 16. Combining the genetic variation observed for the characterized loci provides a unique genotype for all the individuals tested. Using intraspecific controlled crosses of Q. robur trees Mendelian inheritance could be shown for five loci.
Proceedings of The National Academy of Sciences, 1991
A 13,863-base-pair (bp) putative centromeric DNA fragment has been isolated from a human genomic ... more A 13,863-base-pair (bp) putative centromeric DNA fragment has been isolated from a human genomic library by using a probe obtained from metaphase chromosomes of human colon carcinoma cells. The abundance of this DNA was estimated to be 16-32 copies per genome. Cotransfection of mouse cells with this sequence and a selectable marker gene (aminoglycoside 3'-phosphotransferase type II, APH-II) resulted in
Oak chloroplast DNA (cpDNA) variation was studied in a grid-based inventory in western Central Eu... more Oak chloroplast DNA (cpDNA) variation was studied in a grid-based inventory in western Central Europe, including Belgium, The Netherlands, Luxembourg, Germany, the Czech Republic, and the northern parts of Upper and Lower Austria. A total of 2155 trees representing 426 populations of Quercus robur L. and Q. petraea (Matt.) Liebl. were screened for polymorphism in up to four PCR-amplified cpDNA
A genetic map of Pedunculate oak (Quercus robur) was constructed based on one 5S rDNA, 271 RAPD, ... more A genetic map of Pedunculate oak (Quercus robur) was constructed based on one 5S rDNA, 271 RAPD, ten SCAR, 18 microsatellite, one minisatellite, and six isozyme markers. A total of 94 individuals from a full-sib family was genotyped. Two maps, including 307 markers, were constructed according to the “two-way pseudo-testcross” mapping strategy. Testcross markers segregating in the 1 : 1 ratio were
Available evidence shows that sweetpotato originated from either Central or South American lowlan... more Available evidence shows that sweetpotato originated from either Central or South American lowlands with subsequent dispersal to North America, Europe, Africa, Asia and the pacific islands. A total of 71 polymorphic RAPD molecular markers were used to assess the genetic relationships amongst 74 sweetpotato varieties originating from a total of 23 sweetpotato producing countries within six geographical regions, namely, South
RNaseH-LTR regions of the Ty1-copia retrotransposon were amplified and cloned from the sweetpotat... more RNaseH-LTR regions of the Ty1-copia retrotransposon were amplified and cloned from the sweetpotato genome using RNaseH gene-specific degenerate primers and restriction site-specific adaptor primers. Ninety clones out of the 240 sequenced were identified with a variable degree of homology to the Ty1-copia RNaseH gene. Three ( Str6, Str85, Str187) of the 90 had characteristic RNaseH-gene, stop codon, polypurine track and putative 3' LTR sequence elements. Analysis of nine selected genotypes representing Africa, South and Central America, as well as Papua New Guinea, by the established S-SAP technique revealed that the majority of the Ty1-copia transposon insertions were unique (33 to 64%) and only few common bands were detected. Analysis of 177 East African varieties further supported this finding and showed that most of the copia retrotransposon locations were represented only by some genotypes. Considering that sweetpotato has been present in the East African region for only about 500 years, and the number of genotypes introduced was possibly limited, a surprisingly high level of genetic variability of the transposon insertion sites was detected. These findings may indicate the putative activity of the retrotransposon in sweetpotato in the recent past. Comparison of the copia retrotransposon insertion-based S-SAP method to AFLP and RAPD showed that the majority of the markers were more polymorphic (97-99%) in the case of S-SAP in comparison to AFLP (70-90%) and RAPD (88%). Thus demonstrating the transposon-based molecular marker system was very efficient for genotyping.
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