scholarly journals Genomic Organization and Generation of Genetic Variability in the RHS (Retrotransposon Hot Spot) Protein Multigene Family in Trypanosoma cruzi

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1085
Author(s):  
Werica P. Bernardo ◽  
Renata T. Souza ◽  
André G. Costa-Martins ◽  
Eden R. Ferreira ◽  
Renato A. Mortara ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Genomic Organization ◽  
Hot Spot ◽  
Crossing Over ◽  
Target Sequence ◽  
Nuclear Region ◽  
Monophyletic Origin ◽  
Ectopic Recombination ◽  
Transcribed Sequences ◽  
Shed Light

Retrotransposon Hot Spot (RHS) is the most abundant gene family in Trypanosoma cruzi, with unknown function in this parasite. The aim of this work was to shed light on the organization and expression of RHS in T. cruzi. The diversity of the RHS protein family in T. cruzi was demonstrated by phylogenetic and recombination analyses. Transcribed sequences carrying the RHS domain were classified into ten distinct groups of monophyletic origin. We identified numerous recombination events among the RHS and traced the origins of the donors and target sequences. The transcribed RHS genes have a mosaic structure that may contain fragments of different RHS inserted in the target sequence. About 30% of RHS sequences are located in the subtelomere, a region very susceptible to recombination. The evolution of the RHS family has been marked by many events, including gene duplication by unequal mitotic crossing-over, homologous, as well as ectopic recombination, and gene conversion. The expression of RHS was analyzed by immunofluorescence and immunoblotting using anti-RHS antibodies. RHS proteins are evenly distributed in the nuclear region of T. cruzi replicative forms (amastigote and epimastigote), suggesting that they could be involved in the control of the chromatin structure and gene expression, as has been proposed for T. brucei.

scholarly journals Benznidazole Treatment following Acute Trypanosoma cruzi Infection Triggers CD8+ T-Cell Expansion and Promotes Resistance to Reinfection

2002 ◽  
Vol 46 (12) ◽  
pp. 3790-3796 ◽  
Author(s):  
Bianca Perdigão Olivieri ◽  
Vinícius Cotta-de-Almeida ◽  
Tania Araújo-Jorge
Keyword(s):  
T Lymphocytes ◽  
Trypanosoma Cruzi ◽  
Immune Regulation ◽  
Immune Dysregulation ◽  
Direct Role ◽  
Parasite Replication ◽  
The Impact ◽  
Shed Light ◽  
Cruzi Infection

ABSTRACT Many studies have shed light on the mechanisms underlying both immunoprotection and immune dysregulation arising after Trypanosoma cruzi infection. However, little is known about the impact of benznidazole (N-benzyl-2-nitroimidazole acetamide), the drug available for clinical treatment of the infection, on the immune system in the infected host. In the present study we investigated the effect of benznidazole therapy on the lymphoid compartment during the course of experimental T. cruzi infection. Although amelioration of a variety of clinical and parasitological signs was observed in treated mice, amelioration of splenocyte expansion was not detected. Interestingly, this sustained splenomegaly observed in benznidazole-treated mice showed a preferential expansion of CD8+ T lymphocytes. Moreover, although benznidazole treatment blocked the expansion of recently activated CD4+ and CD8+ T cells seen in infected hosts, benznidazole treatment led to a selective expansion of effector and memory CD8+ T lymphocytes in association with a lower rate of apoptosis. In addition, the surviving treated animals were protected from reinfection. Together, these data suggest that, in addition to its well-known direct role in blocking parasite replication in vivo, benznidazole appears to directly affect immune regulation in T. cruzi-infected hosts.

scholarly journals The M26 Hotspot of Schizosaccharomyces pombe Stimulates Meiotic Ectopic Recombination and Chromosomal Rearrangements

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1191-1204 ◽  
Author(s):  
Jeffrey B Virgin ◽  
Jeffrey P Bailey
Keyword(s):  
Homologous Recombination ◽  
Schizosaccharomyces Pombe ◽  
Dna Sequences ◽  
Chromosomal Rearrangements ◽  
Low Frequency ◽  
Repeated Sequences ◽  
Crossing Over ◽  
Ectopic Recombination ◽  
Recombination Hotspots ◽  
Integration Sites

Abstract Homologous recombination is increased during meiosis between DNA sequences at the same chromosomal position (allelic recombination) and at different chromosomal positions (ectopic recombination). Recombination hotspots are important elements in controlling meiotic allelic recombination. We have used artificially dispersed copies of the ade6 gene in Schizosaccharomyces pombe to study hotspot activity in meiotic ectopic recombination. Ectopic recombination was reduced 10–1000-fold relative to allelic recombination, and was similar to the low frequency of ectopic recombination between naturally repeated sequences in S. pombe. The M26 hotspot was active in ectopic recombination in some, but not all, integration sites, with the same pattern of activity and inactivity in ectopic and allelic recombination. Crossing over in ectopic recombination, resulting in chromosomal rearrangements, was associated with 35–60% of recombination events and was stimulated 12-fold by M26. These results suggest overlap in the mechanisms of ectopic and allelic recombination and indicate that hotspots can stimulate chromosomal rearrangements.

scholarly journals The genomic organization and transcription of the ubiquitin genes of Trypanosoma cruzi.

1988 ◽  
Vol 7 (4) ◽  
pp. 1121-1127 ◽  
Author(s):  
J. Swindle ◽  
J. Ajioka ◽  
H. Eisen ◽  
B. Sanwal ◽  
C. Jacquemot ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Genomic Organization

Genomic organization and transcription analysis of the 195-bp satellite DNA in Trypanosoma cruzi

2008 ◽  
Vol 160 (1) ◽  
pp. 60-64 ◽  
Author(s):  
Camila Martins ◽  
Cassio Silva Baptista ◽  
Susan Ienne ◽  
Gustavo C. Cerqueira ◽  
Daniella C. Bartholomeu ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Satellite Dna ◽  
Genomic Organization ◽  
Transcription Analysis

Infrared array imaging and spectrophotometry of the nuclear region of the 'hot-spot' galaxy NGC 2903

1988 ◽  
Vol 335 ◽  
pp. 126 ◽  
Author(s):  
D. A. Simons ◽  
D. L. Depoy ◽  
E. E. Becklin ◽  
R. W. Capps ◽  
K.-W. Hodapp ◽  
...  
Keyword(s):  
Hot Spot ◽  
Nuclear Region ◽  
Array Imaging ◽  
Infrared Array

Predicted amino acid sequence and genomic organization of Trypanosoma cruzi hsp 60 genes

1993 ◽  
Vol 58 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Marcia Giambiagi-de Marval ◽  
Keith Gottesdiener ◽  
Edson Rondinelli ◽  
Lex H.T. Van der Ploeg
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Trypanosoma Cruzi ◽  
Genomic Organization ◽  
Predicted Amino Acid Sequence

Identification of the first duplication in MYH9-related disease: A hot spot for unequal crossing-over within exon 24 of the MYH9 gene

2009 ◽  
Vol 52 (4) ◽  
pp. 191-194 ◽  
Author(s):  
Daniela De Rocco ◽  
Nuria Pujol-Moix ◽  
Alessandro Pecci ◽  
Flavio Faletra ◽  
Valeria Bozzi ◽  
...  
Keyword(s):  
Hot Spot ◽  
Crossing Over ◽  
Unequal Crossing Over ◽  
Related Disease ◽  
Myh9 Gene

scholarly journals Repertoire, Genealogy and Genomic Organization of Cruzipain and Homologous Genes in Trypanosoma cruzi, T. cruzi-Like and Other Trypanosome Species

PLoS ONE ◽  
2012 ◽  
Vol 7 (6) ◽  
pp. e38385 ◽  
Author(s):  
Luciana Lima ◽  
Paola A. Ortiz ◽  
Flávia Maia da Silva ◽  
João Marcelo P. Alves ◽  
Myrna G. Serrano ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Genomic Organization ◽  
Trypanosome Species ◽  
Homologous Genes

scholarly journals Detection of avian oncogenic Marek’s disease herpesvirus DNA in human sera

2001 ◽  
Vol 82 (1) ◽  
pp. 233-240 ◽  
Author(s):  
S. Laurent ◽  
E. Esnault ◽  
G. Dambrine ◽  
A. Goudeau ◽  
D. Choudat ◽  
...  
Keyword(s):  
Nested Pcr ◽  
Hot Spot ◽  
Health Hazard ◽  
Single Copy ◽  
Marek's Disease ◽  
Target Sequence ◽  
Marek’S Disease ◽  
Serum Samples ◽  
Worldwide Distribution ◽  
Human Sera

The avian herpesvirus Marek’s disease virus (MDV) has a worldwide distribution and is responsible for T-lymphoma in chickens. The question as to whether MDV poses a public health hazard to humans was first raised when the virus was isolated in 1967. However, no irrefutable results have been obtained in immunological and virological studies. We used a nested-PCR to detect MDV DNA in human serum samples. A total of 202 serum samples from individuals exposed and not exposed to poultry was tested by nested-PCR for a target sequence located in the MDV gD gene. The assay system was specific and sensitive, making it possible to detect a single copy of the target sequence. Forty-one (20%) of the 202 serum samples tested positive for MDV DNA. The prevalence of MDV DNA was not significantly different in the group exposed to poultry and the group not exposed to poultry. There was also no difference due to age or sex. Alignment of the 41 gD sequences amplified from human sera with eight gD sequences amplified from MDV-infected chicken sera showed a maximum nucleotide divergence of 1·65%. However, four ‘hot-spot’ mutation sites were identified, defining four groups. Interestingly, two groups contained only human MDV-gD sequences. The status of the MDV genome detected in human blood is discussed.

scholarly journals Gene conversions and crossing over during homologous and homeologous ectopic recombination in Saccharomyces cerevisiae.

Genetics ◽  
1993 ◽  
Vol 135 (1) ◽  
pp. 5-16 ◽  
Author(s):  
S Harris ◽  
K S Rudnicki ◽  
J E Haber
Keyword(s):  
Gene Conversion ◽  
Low Ph ◽  
Ammonium Ion ◽  
Crossing Over ◽  
Hygromycin B ◽  
Wild Type ◽  
Reciprocal Translocations ◽  
Ectopic Recombination ◽  
Shared Identity ◽  
The Difference

Abstract The pma1-105 mutation reduces the activity of the yeast plasma membrane H(+)-ATPase and causes cells to be both low pH and ammonium ion sensitive and resistant to the antibiotic hygromycin B. Revertants that can grow at pH 3.0 and on ammonium-containing plates frequently arise by ectopic recombination between pma1-105 and PMA2, a diverged gene that shares 85% DNA sequence identity with PMA1. The gene conversion tracts of revertants of pma1-105 were determined by DNA sequencing the hybrid PMA1::PMA2 genes. Gene conversion tracts ranged from 18-774 bp. The boundaries of these replacements were short (3-26 bp) regions of sequences that were identical between PMA1 and PMA2. These boundaries were not located at the regions of greatest shared identity between the two PMA genes. Similar results were obtained among low pH-resistant revertants of another mutation, pma1-147. One gene conversion was obtained in which the resulting PMA1::PMA2 hybrid was low pH-resistant but still hygromycin B-resistant. This partially active gene differs from a wild-type revertant only by the presence of two PMA2-encoded amino acid substitutions. Thus, some regions of PMA2 are not fully interchangeable with PMA1. We have also compared the efficiency of recombination between pma1-105 and either homeologous PMA2 sequence or homologous PMA1 donor sequences inserted at the same location. PMA2 x pma1-105 recombination occurred at a rate approximately 75-fold less than PMA1 x pma1-105 events. The difference in homology between the interacting sequences did not affect the proportion of gene conversion events associated with a cross-over, as in both cases approximately 5% of the Pma+ recombinants had undergone reciprocal translocations between the two chromosomes carrying pma1-105 and the donor PMA sequences. Reciprocal translocations were identified by a simple and generally useful nutritional test.

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