Chromosomal size variation in Trypanosoma cruzi is mainly progressive and is evolutionarily informative

Parasitology ◽  
2002 ◽  
Vol 124 (3) ◽  
pp. 277-286 ◽  
Author(s):  
J. HENRIKSSON ◽  
J. C. DUJARDIN ◽  
C. BARNABÉ ◽  
S. BRISSE ◽  
G. TIMPERMAN ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Random Amplified Polymorphic Dna ◽  
Clonal Evolution ◽  
Size Variation ◽  
Evolutionary Significance ◽  
Size Difference ◽  
Enzyme Electrophoresis ◽  
Chromosome Size ◽  
Size Polymorphism ◽  
Branching Points

The evolutionary significance of chromosome size polymorphism was explored in a representative panel of 26 Trypanosoma cruzi stocks. We tested a progressive model (aCSDI) assuming that the larger the size difference between homologous chromosomes, the more divergent the parasites are. This was contrasted with a non-progressive model (Jaccard's distance), in which any chromosome size difference has the same weight. ACSDI-based dendrograms were very similar to those built-up from multilocus enzyme electrophoresis (MLEE) and random amplified polymorphic DNA (RAPD) data: structuring in 2 major lineages (T. cruzi I and T. cruzi II) and 5 small subdivisions within T. cruzi II was identical, and branching was very similar. Furthermore, a significant correlation (P<0·001) was observed between aCSDI and phenetic distances calculated from MLEE and RAPD data. In contrast, analysis of chromosome size polymorphism with Jaccard's distance generated dendrograms with relatively long branches, causing most branching points to cluster close together, which generates statistically uncertain branching points. Our results thus support a model of progressive chromosome size-variation and show that despite an extensive polymorphism, chromosomal sizes constitute valuable characters for evolutionary analyses. Furthermore, our data are consistent with the clonal evolution model previously proposed for T. cruzi.

scholarly journals Differential Gene Expression in Benznidazole-Resistant Trypanosoma cruzi Parasites

2005 ◽  
Vol 49 (7) ◽  
pp. 2701-2709 ◽  
Author(s):  
Diana Villarreal ◽  
Philippe Nirdé ◽  
Mallorie Hide ◽  
Christian Barnabé ◽  
Michel Tibayrenc
Keyword(s):  
Gene Expression ◽  
Trypanosoma Cruzi ◽  
Differential Gene Expression ◽  
Drug Exposure ◽  
Dna Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Enzyme Electrophoresis ◽  
Wild Type ◽  
Resistance Level ◽  
Differential Gene

ABSTRACT We analyzed the differential gene expression among representative Trypanosoma cruzi stocks in relation to benznidazole exposures using a random differentially expressed sequences (RADES) technique. Studies were carried out with drug pressure both at the natural susceptibility level of the wild-type parasite (50% inhibitory concentration for the wild type) and at different resistance levels. The pattern of differential gene expression performed with resistant stocks was compared to the population structure of this parasite, established by random amplified polymorphic DNA analysis and multilocus enzyme electrophoresis. A RADES band polymorphism was observed, and over- or underexpression was linked to the resistance level of the stock. The analysis of RADES bands suggested that different products may be involved in benznidazole resistance mechanisms. No significant association was found between phylogenetic clustering and benznidazole susceptibility. Benznidazole resistance may involve several mechanisms, depending on the level of drug exposure.

scholarly journals Patterns of genome size variation in snapping shrimp

Genome ◽  
2016 ◽  
Vol 59 (6) ◽  
pp. 393-402 ◽  
Author(s):  
Nicholas W. Jeffery ◽  
Kristin Hultgren ◽  
Solomon Tin Chi Chak ◽  
T. Ryan Gregory ◽  
Dustin R. Rubenstein
Keyword(s):  
Genome Size ◽  
Phylogenetic Signal ◽  
Size Variation ◽  
Diverse Group ◽  
Chromosome Size ◽  
Genome Size Variation ◽  
Large Genome ◽  
Large Genome Size ◽  
Single Genus ◽  
Geographic Regions

Although crustaceans vary extensively in genome size, little is known about how genome size may affect the ecology and evolution of species in this diverse group, in part due to the lack of large genome size datasets. Here we investigate interspecific, intraspecific, and intracolony variation in genome size in 39 species of Synalpheus shrimps, representing one of the largest genome size datasets for a single genus within crustaceans. We find that genome size ranges approximately 4-fold across Synalpheus with little phylogenetic signal, and is not related to body size. In a subset of these species, genome size is related to chromosome size, but not to chromosome number, suggesting that despite large genomes, these species are not polyploid. Interestingly, there appears to be 35% intraspecific genome size variation in Synalpheus idios among geographic regions, and up to 30% variation in Synalpheus duffyi genome size within the same colony.

scholarly journals Genome size variation in the North American sunfish genus Lepomis (Pisces: Centrarchidae)

1989 ◽  
Vol 53 (3) ◽  
pp. 173-182 ◽  
Author(s):  
Chara J. Ragland ◽  
John R. Gold
Keyword(s):  
Genome Size ◽  
North American ◽  
Size Variation ◽  
Hierarchical Level ◽  
Size Difference ◽  
Similar Data ◽  
Genome Size Variation ◽  
The North ◽  
Essentially Normal ◽  
Genome Size Evolution

SummaryGenome sizes (nuclear DNA contents) were documented spectrophotometrically from individuals of each of nine species of the North American centrarchid (sunfish) genus Lepomis. The distributions of DNA values within and among the nine species were essentially normal and continuous, suggesting that changes in DNA quantity in Lepomis are small in amount, involve both gains and losses of DNA, and are cumulative and independent in effect. Significant differences in mean genome size were found between individuals within populations in all nine species and between species. Nested analysis of variance and comparisons of average genome size difference or distance between individuals drawn from different levels of taxonomic organization revealed that the majority of genome size divergence in Lepomis occurs above the hierarchical level of individuals within populations. The Lepomis data when compared to similar data from North American cyprinid fishes appear to suggest that: (i) genome size evolution in these fishes at least follows a continuous rather than a discontinuous mode; (ii) the general predictions of hypothetical models relating genome size variation as a function of organismal position along adaptive continua may be oversimplified, or not applicable to complex, higher eukaryotes; and (iii) changes in genome size in these fishes may be concentrated in speciation episodes.

Impact of clonal evolution on the biological diversity of Trypanosoma cruzi

Parasitology ◽  
1997 ◽  
Vol 114 (3) ◽  
pp. 213-218 ◽  
Author(s):  
J.-P. LAURENT ◽  
C. BARNABE ◽  
V. QUESNEY ◽  
S. NOEL ◽  
M. TIBAYRENC
Keyword(s):  
Trypanosoma Cruzi ◽  
Biological Diversity ◽  
Clonal Evolution ◽  
Evolutionary Divergence ◽  
Biological Variability ◽  
Profound Impact ◽  
Applied Study ◽  
Biological Differences

Trypanosoma cruzi, the agent of Chagas' disease, exhibits considerable biological variability. Moreover, it has been postulated that populations of this protozoan are subdivided into natural clones, which can be separated from each other by considerable levels of evolutionary divergence. The authors have proposed that this long-term clonal evolution may have a profound impact on Trypanosoma cruzi biological diversity. In order to test this hypothesis, 16 T. cruzi stocks representing 3 major clonal genotypes of the parasite were analysed for 8 different in vitro biological parameters. The overall results show a strong statistical linkage between genetic and biological differences. This is in agreement with the working hypothesis, although a notable biological variability is observable among the stocks of each of the 3 major clonal genotypes. The authors propose that T. cruzi genetic variability must be taken into account in any applied study dealing with this parasite.

scholarly journals Molecular characterization of Trypanosoma cruzi Mexican strains and their behavior in the mouse experimental model

2011 ◽  
Vol 44 (6) ◽  
pp. 684-690 ◽  
Author(s):  
César Gómez-Hernández ◽  
Karine Rezende-Oliveira ◽  
Gabriel Antônio Nogueira Nascentes ◽  
Lara Rocha Batista ◽  
Henrique Borges Kappel ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Random Amplified Polymorphic Dna ◽  
Geographic Origin ◽  
Pcr Amplification ◽  
Biological Characterization ◽  
Long Time ◽  
Intergenic Regions ◽  
Mexican Strains

INTRODUCTION: For a long time, the importance of Chagas disease in Mexico, where many regarded it as an exotic malady, was questioned. Considering the great genetic diversity among isolates of Trypanosoma cruzi, the importance of this biological characterization, and the paucity of information on the clinical and biological aspects of Chagas disease in Mexico, this study aimed to identify the molecular and biological characterization of Trypanosoma cruzi isolates from different endemic areas of this country, especially of the State of Jalisco. METHODS: Eight Mexican Trypanosoma cruzi strains were biologically and genetically characterized (PCR specific for Trypanosoma cruzi, multiplex-PCR, amplification of space no transcript of the genes of the mini-exon, amplification of polymorphic regions of the mini-exon, classification by amplification of intergenic regions of the spliced leader genes, RAPD - (random amplified polymorphic DNA). RESULTS: Two profiles of parasitaemia were observed, patent (peak parasitaemia of 4.6×10(6) to 10(7) parasites/mL) and subpatent. In addition, all isolates were able to infect 100% of the animals. The isolates mainly displayed tropism for striated (cardiac and skeletal) muscle. PCR amplification of the mini-exon gene classified the eight strains as TcI. The RAPD technique revealed intraspecies variation among isolates, distinguishing strains isolated from humans and triatomines and according to geographic origin. CONCLUSIONS: The Mexican T. cruzi strains are myotrophic and belong to group TcI.

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