The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform
Liwang Cui - One of the best experts on this subject based on the ideXlab platform.
-
Molecular evolution and Intragenic Recombination of the merozoite surface protein MSP-3α from the malaria parasite Plasmodium vivax in Thailand
Parasitology, 2005Co-Authors: C. N. Mascorro, Ananias A Escalante, K. Zhao, Benjawan Khuntirat, Jetsumon Sattabongkot, Guiyun Yan, Liwang CuiAbstract:Abstract The merozoite surface antigens of malaria parasites are prime anti-morbidity/mortality vaccine candidates. However, their highly polymorphic nature requires extensive surveys of parasite populations to validate vaccine designs. Previous studies have found 3 molecular types (A, B and C) of the Plasmodium vivax merozoite surface protein 3a (PvMSP-3alpha) among parasite field populations. Here we analysed complete PvMSP-3alpha sequences from 17 clinical P. vivax isolates from Thailand and found that the nucleotide diversity was as high as that from samples widely separated by time and space. The polymorphic sites were not randomly distributed but concentrated in the N-terminal Ala-rich domain (block 2A), which is partially deleted in type B and C sequences. The size variations among type A sequences were due to small indels occurring in block 2A, whereas type B and C sequences were uniform in length with each type having a different large deletion. Analysis of synonymous and non-synonymous substitutions suggested that different selection forces were operating on different regions of the molecule. The numerous Recombination sites detected within the Ala-rich domain suggested that Intragenic Recombination was at least partially responsible for the observed genetic diversity of the PvMSP-3alpha gene. Phylogenetic analysis failed to link any alleles to a specific geographical origin, even when different domains of PvMSP-3alpha were used for analysis. The highly polymorphic nature and lack of geographical clustering of isolates suggest that more systematic investigations of the PvMSP-3alpha gene are needed to explore its evolution and vaccine potential.
-
Molecular evolution and Intragenic Recombination of the merozoite surface protein MSP-3alpha from the malaria parasite Plasmodium vivax in Thailand.
Parasitology, 2005Co-Authors: C. N. Mascorro, K. Zhao, Benjawan Khuntirat, Jetsumon Sattabongkot, Guiyun Yan, A A Escalante, Liwang CuiAbstract:The merozoite surface antigens of malaria parasites are prime anti-morbidity/mortality vaccine candidates. However, their highly polymorphic nature requires extensive surveys of parasite populations to validate vaccine designs. Previous studies have found 3 molecular types (A, B and C) of the Plasmodium vivax merozoite surface protein 3a (PvMSP-3alpha) among parasite field populations. Here we analysed complete PvMSP-3alpha sequences from 17 clinical P. vivax isolates from Thailand and found that the nucleotide diversity was as high as that from samples widely separated by time and space. The polymorphic sites were not randomly distributed but concentrated in the N-terminal Ala-rich domain (block 2A), which is partially deleted in type B and C sequences. The size variations among type A sequences were due to small indels occurring in block 2A, whereas type B and C sequences were uniform in length with each type having a different large deletion. Analysis of synonymous and non-synonymous substitutions suggested that different selection forces were operating on different regions of the molecule. The numerous Recombination sites detected within the Ala-rich domain suggested that Intragenic Recombination was at least partially responsible for the observed genetic diversity of the PvMSP-3alpha gene. Phylogenetic analysis failed to link any alleles to a specific geographical origin, even when different domains of PvMSP-3alpha were used for analysis. The highly polymorphic nature and lack of geographical clustering of isolates suggest that more systematic investigations of the PvMSP-3alpha gene are needed to explore its evolution and vaccine potential.
Jürgen Horst - One of the best experts on this subject based on the ideXlab platform.
-
A deletion/insertion leading to the generation of a direct repeat as a result of slipped mispairing and Intragenic Recombination in the factor VIII gene.
Human genetics, 1999Co-Authors: Kamiab Tavassoli, Antonin Eigel, Jürgen HorstAbstract:A deletion/insertion in the human factor VIII gene was found in a patient with severe hemophilia A; 316 bp were removed, viz., those enclosing part of intron 15 and the first 7 bp of exon 16. In addition to the deletion, 6 bp were added to the deletion breakpoints; this resulted in the duplication of an existing 13-bp unit. Thus, an overlapping 13-bp direct repeat was generated at the deletion junction. Moreover, the deleted fragment itself was flanked by two homologous 6-bp sequences, one unit being lost by the deletion. A combination of slipped mispairing during replication and an Intragenic Recombination is discussed to describe this deletion/insertion process.
-
a deletion insertion leading to the generation of a direct repeat as a result of slipped mispairing and Intragenic Recombination in the factor viii gene
Human Genetics, 1999Co-Authors: Kamiab Tavassoli, Antonin Eigel, Jürgen HorstAbstract:A deletion/insertion in the human factor VIII gene was found in a patient with severe hemophilia A; 316 bp were removed, viz., those enclosing part of intron 15 and the first 7 bp of exon 16. In addition to the deletion, 6 bp were added to the deletion breakpoints; this resulted in the duplication of an existing 13-bp unit. Thus, an overlapping 13-bp direct repeat was generated at the deletion junction. Moreover, the deleted fragment itself was flanked by two homologous 6-bp sequences, one unit being lost by the deletion. A combination of slipped mispairing during replication and an Intragenic Recombination is discussed to describe this deletion/insertion process.
Jorge A Gomez - One of the best experts on this subject based on the ideXlab platform.
-
Evidence of rotavirus Intragenic Recombination between two sublineages of the same genotype.
The Journal of general virology, 2004Co-Authors: Gabriel I Parra, Karin Bok, Magaly Martínez, Jorge A GomezAbstract:Rotavirus G4 prevalence increased during the past decade, with one of the highest prevalences reported during rotavirus surveillance in Argentina. Intragenotype diversity analysis has led to its subdivision into lineages (I and II) and sublineages (Ia-Id). On analysis of Argentine and G4 VP7 sequences from other locations, one Argentine strain (ArgRes1723) appeared to be an intermediate between G4 sublineages Ib and Ic. Similarity and bootscanning analyses and Sawyer's test were carried out to demonstrate the recombinant nature of this strain. It was concluded that Intragenic Recombination occurred between sequences of sublineages Ib and Ic, with a crossover point between nucleotide positions 336 and 387. This study constitutes the first report of a mechanism of evolution in rotaviruses that is currently considered unusual - a Recombination event between two strains of the same rotavirus genotype. These results will help increase current knowledge about rotavirus evolution and divergence, improving our understanding of the adaptation mechanisms used by these viruses.
C. N. Mascorro - One of the best experts on this subject based on the ideXlab platform.
-
Molecular evolution and Intragenic Recombination of the merozoite surface protein MSP-3α from the malaria parasite Plasmodium vivax in Thailand
Parasitology, 2005Co-Authors: C. N. Mascorro, Ananias A Escalante, K. Zhao, Benjawan Khuntirat, Jetsumon Sattabongkot, Guiyun Yan, Liwang CuiAbstract:Abstract The merozoite surface antigens of malaria parasites are prime anti-morbidity/mortality vaccine candidates. However, their highly polymorphic nature requires extensive surveys of parasite populations to validate vaccine designs. Previous studies have found 3 molecular types (A, B and C) of the Plasmodium vivax merozoite surface protein 3a (PvMSP-3alpha) among parasite field populations. Here we analysed complete PvMSP-3alpha sequences from 17 clinical P. vivax isolates from Thailand and found that the nucleotide diversity was as high as that from samples widely separated by time and space. The polymorphic sites were not randomly distributed but concentrated in the N-terminal Ala-rich domain (block 2A), which is partially deleted in type B and C sequences. The size variations among type A sequences were due to small indels occurring in block 2A, whereas type B and C sequences were uniform in length with each type having a different large deletion. Analysis of synonymous and non-synonymous substitutions suggested that different selection forces were operating on different regions of the molecule. The numerous Recombination sites detected within the Ala-rich domain suggested that Intragenic Recombination was at least partially responsible for the observed genetic diversity of the PvMSP-3alpha gene. Phylogenetic analysis failed to link any alleles to a specific geographical origin, even when different domains of PvMSP-3alpha were used for analysis. The highly polymorphic nature and lack of geographical clustering of isolates suggest that more systematic investigations of the PvMSP-3alpha gene are needed to explore its evolution and vaccine potential.
-
Molecular evolution and Intragenic Recombination of the merozoite surface protein MSP-3alpha from the malaria parasite Plasmodium vivax in Thailand.
Parasitology, 2005Co-Authors: C. N. Mascorro, K. Zhao, Benjawan Khuntirat, Jetsumon Sattabongkot, Guiyun Yan, A A Escalante, Liwang CuiAbstract:The merozoite surface antigens of malaria parasites are prime anti-morbidity/mortality vaccine candidates. However, their highly polymorphic nature requires extensive surveys of parasite populations to validate vaccine designs. Previous studies have found 3 molecular types (A, B and C) of the Plasmodium vivax merozoite surface protein 3a (PvMSP-3alpha) among parasite field populations. Here we analysed complete PvMSP-3alpha sequences from 17 clinical P. vivax isolates from Thailand and found that the nucleotide diversity was as high as that from samples widely separated by time and space. The polymorphic sites were not randomly distributed but concentrated in the N-terminal Ala-rich domain (block 2A), which is partially deleted in type B and C sequences. The size variations among type A sequences were due to small indels occurring in block 2A, whereas type B and C sequences were uniform in length with each type having a different large deletion. Analysis of synonymous and non-synonymous substitutions suggested that different selection forces were operating on different regions of the molecule. The numerous Recombination sites detected within the Ala-rich domain suggested that Intragenic Recombination was at least partially responsible for the observed genetic diversity of the PvMSP-3alpha gene. Phylogenetic analysis failed to link any alleles to a specific geographical origin, even when different domains of PvMSP-3alpha were used for analysis. The highly polymorphic nature and lack of geographical clustering of isolates suggest that more systematic investigations of the PvMSP-3alpha gene are needed to explore its evolution and vaccine potential.
Gabriel I Parra - One of the best experts on this subject based on the ideXlab platform.
-
Evidence of rotavirus Intragenic Recombination between two sublineages of the same genotype.
The Journal of general virology, 2004Co-Authors: Gabriel I Parra, Karin Bok, Magaly Martínez, Jorge A GomezAbstract:Rotavirus G4 prevalence increased during the past decade, with one of the highest prevalences reported during rotavirus surveillance in Argentina. Intragenotype diversity analysis has led to its subdivision into lineages (I and II) and sublineages (Ia-Id). On analysis of Argentine and G4 VP7 sequences from other locations, one Argentine strain (ArgRes1723) appeared to be an intermediate between G4 sublineages Ib and Ic. Similarity and bootscanning analyses and Sawyer's test were carried out to demonstrate the recombinant nature of this strain. It was concluded that Intragenic Recombination occurred between sequences of sublineages Ib and Ic, with a crossover point between nucleotide positions 336 and 387. This study constitutes the first report of a mechanism of evolution in rotaviruses that is currently considered unusual - a Recombination event between two strains of the same rotavirus genotype. These results will help increase current knowledge about rotavirus evolution and divergence, improving our understanding of the adaptation mechanisms used by these viruses.
-
Short Communication Evidence of rotavirus Intragenic Recombination between two sublineages of the same genotype
2004Co-Authors: Gabriel I Parra, Karin Bok, Jorge GomezAbstract:Rotavirus G4 prevalence increased during the past decade, with one of the highest prevalencesreported during rotavirus surveillance in Argentina. Intragenotype diversity analysis has led toits subdivision into lineages (I and II) and sublineages (Ia–Id). On analysis of Argentine and G4VP7 sequences from other locations, one Argentine strain (ArgRes1723) appeared to bean intermediate between G4 sublineages Ib and Ic. Similarity and bootscanning analyses andSawyer’s test were carried out to demonstrate the recombinant nature of this strain. It wasconcluded that Intragenic Recombination occurred between sequences of sublineages Ib and Ic,with a crossover point between nucleotide positions 336 and 387. This study constitutes thefirst report of a mechanism of evolution in rotaviruses that is currently considered unusual – aRecombination event between two strains of the same rotavirus genotype. These results willhelp increase current knowledge about rotavirus evolution and divergence, improving ourunderstanding of the adaptation mechanisms used by these viruses.