scholarly journals The Structure of a Conserved Telomeric Region Associated with Variant Antigen Loci in the Blood Parasite Trypanosoma congolense

2018 ◽  
Vol 10 (9) ◽  
pp. 2458-2473 ◽  
Author(s):  
Ali Hadi Abbas ◽  
Sara Silva Pereira ◽  
Simon D'Archivio ◽  
Bill Wickstead ◽  
Liam J Morrison ◽  
...  
Keyword(s):  
Trypanosoma Congolense ◽  
Blood Parasite ◽  
Telomeric Region ◽  
Variant Antigen

Evidence for genetic diversity in Trypanosoma (Nannomonas) congolense

Parasitology ◽  
1986 ◽  
Vol 93 (2) ◽  
pp. 291-304 ◽  
Author(s):  
P. A. O. Majiva ◽  
R. Hamers ◽  
N. Van Meirvenne ◽  
G. Matthyssens
Keyword(s):  
Genetic Diversity ◽  
Trypanosoma Brucei ◽  
Restriction Enzyme ◽  
Dna Sequences ◽  
Genomic Dna ◽  
Trypanosoma Congolense ◽  
Synthetic Oligonucleotide ◽  
Hybridization Probes ◽  
Conserved Genes ◽  
Variant Antigen

SUMMARYGenetic proximity between two karyotypic groups of Trypanosoma congolense was investigated using as hybridization probes: (i) total genomic DNA, (ii) a 35 nucleotide long synthetic oligonucleotide, and (iii) non-variant antigen type (non-VAT) specific complementary DNAs. The phylogenetic relationship between Trypanosoma brucei and T. evansi, both of which are accepted species in the subgenus Trypanozoon, was used as a reference to assess the phylogenetic proximity of the two groups of T. congolense. Results indicate that some morphologically indistinguishable T. congolense populations differ in a variety of molecular and genetic properties: molecular karyotypes, majority of the DNA sequences, and the restriction enzyme sites in the genomic environments of various conserved genes. The implications of these findings for trypanosome evolution and T. congolense epidemiology are discussed.

Diagnosis and successful treatment of an Austrian dog infected with Trypanosoma congolense forest type

2021 ◽  
Vol 49 (02) ◽  
pp. 142-147
Author(s):  
Michael Leschnik ◽  
Katja Silbermayr ◽  
Abigail Guija ◽  
Barbara Nell
Keyword(s):  
Clinical Improvement ◽  
Successful Treatment ◽  
Initial Treatment ◽  
Blood Smear ◽  
Forest Type ◽  
Trypanosoma Congolense ◽  
Lethal Outcome ◽  
Complete Eradication ◽  
Western Africa ◽  
Mongrel Dog

AbstractCanine African Trypanosomosis (CAT) is a rarely described disease with frequently lethal outcome. A 5-year-old female mongrel dog weighing 22 kg was presented in Austria due to unilateral uveitis, pancytopenia, and anorexia 4 months after return from a trip through Western Africa. Trypanosoma spp. flagellates were detected in a blood smear and identified as Trypanosoma congolense forest type by PCR. Initial treatment with imidocarb and miltefosine led to clinical improvement but only isometamidium chloride hydrochloride applied intramuscularly led to complete eradication of the pathogen from the dog’s blood 4 months later.

scholarly journals Adaptive Admixture of HLA class I Allotypes Enhanced Genetically Determined Strength of Natural Killer Cells in East Asians

2021 ◽  
Author(s):  
Zhihui Deng ◽  
Jianxin Zhen ◽  
Genelle F Harrison ◽  
Guobin Zhang ◽  
Rui Chen ◽  
...  
Keyword(s):  
Natural Killer ◽  
High Frequency ◽  
Nk Cell ◽  
Killer Cell ◽  
Hla Class I ◽  
Class I ◽  
Telomeric Region ◽  
East Asians ◽  
Cell Functions ◽  
Specific Receptors

Abstract Human natural killer (NK) cells are essential for controlling infection, cancer and fetal development. NK cell functions are modulated by interactions between polymorphic inhibitory killer cell immunoglobulin-like receptors (KIR) and polymorphic HLA-A, -B and -C ligands expressed on tissue cells. All HLA-C alleles encode a KIR ligand and contribute to reproduction and immunity. In contrast, only some HLA-A and -B alleles encode KIR ligands and they focus on immunity. By high-resolution analysis of KIR and HLA-A, -B and -C genes, we show that the Chinese Southern Han are significantly enriched for interactions between inhibitory KIR and HLA-A and -B. This enrichment has had substantial input through population admixture with neighboring populations, who contributed HLA class I haplotypes expressing the KIR ligands B*46:01 and B*58:01, which subsequently rose to high frequency by natural selection. Consequently, over 80% of Southern Han HLA haplotypes encode more than one KIR ligand. Complementing the high number of KIR ligands, the Chinese Southern Han KIR locus combines a high frequency of genes expressing potent inhibitory KIR, with a low frequency of those expressing activating KIR. The Southern Han centromeric KIR region encodes strong, conserved, inhibitory HLA-C specific receptors, and the telomeric region provides a high number and diversity of inhibitory HLA-A and -B specific receptors. In all these characteristics, the Chinese Southern Han represent other East Asians, whose NK cell repertoires are thus enhanced in quantity, diversity and effector strength, likely augmenting resistance to endemic viral infections.

Observations on the Metabolism of the Culture Form of Trypanosoma congolense

1959 ◽  
Vol 45 (2) ◽  
pp. 204 ◽  
Author(s):  
Theodor von Brand ◽  
Eleanor Johnson Tobie
Keyword(s):  
Trypanosoma Congolense ◽  
Culture Form

scholarly journals Analysis of the Functions of Recombination-Related Genes in the Generation of Large Chromosomal Deletions by Loop-Out Recombination in Aspergillus oryzae

2012 ◽  
Vol 11 (4) ◽  
pp. 507-517 ◽  
Author(s):  
Tadashi Takahashi ◽  
Masahiro Ogawa ◽  
Yasuji Koyama
Keyword(s):  
Aspergillus Oryzae ◽  
Chromosomal Region ◽  
Centromeric Region ◽  
Chromosome 8 ◽  
Telomeric Region ◽  
Dna Double Strand Breaks ◽  
Chromosomal Structure ◽  
Content Type ◽  
Strand Breaks ◽  
Chromosomal Deletions

ABSTRACT Loop-out-type recombination is a type of intrachromosomal recombination followed by the excision of a chromosomal region. The detailed mechanism underlying this recombination and the genes involved in loop-out recombination remain unknown. In the present study, we investigated the functions of ku70 , ligD , rad52 , rad54 , and rdh54 in the construction of large chromosomal deletions via loop-out recombination and the effect of the position of the targeted chromosomal region on the efficiency of loop-out recombination in Aspergillus oryzae . The efficiency of generation of large chromosomal deletions in the near-telomeric region of chromosome 3, including the aflatoxin gene cluster, was compared with that in the near-centromeric region of chromosome 8, including the tannase gene. In the Δ ku70 and Δ ku70-rdh54 strains, only precise loop-out recombination occurred in the near-telomeric region. In contrast, in the Δ ligD , Δ ku70-rad52 , and Δ ku70-rad54 strains, unintended chromosomal deletions by illegitimate loop-out recombination occurred in the near-telomeric region. In addition, large chromosomal deletions via loop-out recombination were efficiently achieved in the near-telomeric region, but barely achieved in the near-centromeric region, in the Δ ku70 strain. Induction of DNA double-strand breaks by I-SceI endonuclease facilitated large chromosomal deletions in the near-centromeric region. These results indicate that ligD , rad52 , and rad54 play a role in the generation of large chromosomal deletions via precise loop-out-type recombination in the near-telomeric region and that loop-out recombination between distant sites is restricted in the near-centromeric region by chromosomal structure.

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