scholarly journals Study on the Occurrence of Genetic Exchange Among Parasites of the Leishmania mexicana Complex

2020 ◽  
Vol 10 ◽  
Author(s):  
Roman Telittchenko ◽  
Albert Descoteaux
Keyword(s):  
Drug Resistance ◽  
Genetic Exchange ◽  
Sand Fly ◽  
Leishmania Mexicana ◽  
Resistance Markers ◽  
Axenic Cultures ◽  
Integrated Or ◽  
Genetic Events

In Leishmania, genetic exchange has been experimentally demonstrated to occur in the sand fly vector and in promastigote axenic cultures through a meiotic-like process. No evidence of genetic exchange in mammalian hosts have been reported so far, possibly due to the fact that the Leishmania species used in previous studies replicate within individual parasitophorous vacuoles. In the present work, we explored the possibility that residing in communal vacuoles may provide conditions favorable for genetic exchange for L. mexicana and L. amazonensis. Using promastigote lines of both species harboring integrated or episomal drug-resistance markers, we assessed whether genetic exchange can occur in axenic cultures, in infected macrophages as well as in infected mice. We obtained evidence of genetic exchange for L. amazonensis in both axenic promastigote cultures and infected macrophages. However, the resulting products of those putative genetic events were unstable as they did not sustain growth in subsequent sub-cultures, precluding further characterization.

scholarly journals RE-EVALUATION OF MALARIA DIAGNOSIS BY MOLECULAR METHODS REVEALS MUTATIONS IN HRP-2 AND DRUG RESISTANCE MARKERS IN CAMEROON

2017 ◽  
Vol 2 (Suppl 2) ◽  
pp. A21.3-A22
Author(s):  
Palmer Netongo ◽  
Séverin Kamdem ◽  
Thirumalaisamy Velavan ◽  
Peter Kremsner
Keyword(s):  
Drug Resistance ◽  
Malaria Diagnosis ◽  
Molecular Methods ◽  
Resistance Markers

scholarly journals Molecular Surveillance of Plasmodium falciparum Drug Resistance Markers in Clinical Samples from Botswana

2018 ◽  
Vol 99 (6) ◽  
pp. 1499-1503 ◽  
Author(s):  
Leabaneng Tawe ◽  
Michela Menegon ◽  
Pleasure Ramatlho ◽  
Charles W. Muthoga ◽  
Naledi Mutukwa ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Clinical Samples ◽  
Molecular Surveillance ◽  
Resistance Markers

scholarly journals GENETICS OF CHLAMYDOMONAS REINHARDTII DIPLOIDS. II. THE EFFECTS OF DIPLOIDY AND ANEUPLOIDY ON THE TRANSMISSION OF NON-MENDELIAN MARKERS

Genetics ◽  
1984 ◽  
Vol 107 (4) ◽  
pp. 563-576
Author(s):  
Eva M Eves ◽  
Kwen-Sheng Chiang
Keyword(s):  
Drug Resistance ◽  
Chloroplast Dna ◽  
Chlamydomonas Reinhardtii ◽  
Cell Line ◽  
Mating Type ◽  
Secondary Effect ◽  
Chloroplast Gene ◽  
A Cell ◽  
Resistance Markers ◽  
Normal Laboratory

ABSTRACT The transmission of two non-Mendelian drug resistance markers has been studied in crosses of Chlamydomonas reinhardtii involving diploids and aneuploids with different mating type genotypes. Under normal laboratory conditions for gametogenesis, mating and zygote maturation, the transmission pattern of the non-Mendelian markers sr-u-1 (resistance to streptomycin) and spr-u-1-27-3 (resistance to spectinomycin) is primarily determined by the mating type genotypes of the parental cells. Our results confirm and expand an earlier observation suggesting that an apparent codominant function of the female (mt  +) allele in regulating chloroplast gene transmission in meiosis appears to be distinct and separate from its recessive function in regulating mating behavior. The chloroplast DNA complement (as indexed by the number of extranuclear DNA-containing bodies) may exert a secondary effect on the transmission of these markers. Within a mating type group (mt+/mt- or mt-/mt-) a cell line with more chloroplast DNA tended to transmit its non-Mendelian markers more frequently than a cell line with less chloroplast DNA.

scholarly journals Molecular detection of drug resistant polymorphisms in Plasmodium falciparum isolates from Southwest, Nigeria

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Monday Tola ◽  
Olumide Ajibola ◽  
Emmanuel Taiwo Idowu ◽  
Olusesan Omidiji ◽  
Samson Taiwo Awolola ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Antimalarial Drug Resistance ◽  
Allelic Discrimination ◽  
Molecular Surveillance ◽  
Malaria Burden ◽  
Two Samples ◽  
Southwest Nigeria ◽  
Resistance Markers ◽  
Drug Interventions

Abstract Objective Nigeria bears 25% of global malaria burden despite concerted efforts towards its control and elimination. The emergence of drug resistance to first line drugs, artemisinin combination therapies (ACTs), indicates an urgent need for continuous molecular surveillance of drug resistance especially in high burden countries where drug interventions are heavily relied on. This study describes mutations in Plasmodium falciparum genes associated with drug resistance in malaria; Pfk13, Pfmdr1, PfATPase6 and Pfcrt in isolates obtained from 83 symptomatic malaria patients collected in August 2014, aged 1–61 years old from South-west Nigeria. Results Two Pfmdr1, N86 and Y184 variants were present at a prevalence of 56% and 13.25% of isolates respectively. There was one synonymous (S679S) and two non-synonymous (M699V, S769M) mutations in the PATPase6 gene, while Pfcrt genotype (CVIET), had a prevalence of 45%. The Pfk13 C580Y mutant allele was suspected by allelic discrimination in two samples with mixed genotypes although this could not be validated with independent isolation or additional methods. Our findings call for robust molecular surveillance of antimalarial drug resistance markers in west Africa especially with increased use of antimalarial drugs as prophylaxis for Covid-19.

Plasmodium vivax drug resistance markers: Genetic polymorphisms and mutation patterns in isolates from Malaysia

Acta Tropica ◽  
2020 ◽  
Vol 206 ◽  
pp. 105454
Author(s):  
Fei-Wen Cheong ◽  
Shairah Dzul ◽  
Mun-Yik Fong ◽  
Yee-Ling Lau ◽  
Sasheela Ponnampalavanar
Keyword(s):  
Drug Resistance ◽  
Plasmodium Vivax ◽  
Genetic Polymorphisms ◽  
Resistance Markers

Sexual processes in the kinetoplastida

Parasitology ◽  
1983 ◽  
Vol 86 (4) ◽  
pp. 29-57 ◽  
Author(s):  
A. Tait
Keyword(s):  
Drug Resistance ◽  
Genetic Exchange ◽  
Sexual Cycle ◽  
Drug Resistant ◽  
Sexual Process ◽  
Experimental Approaches ◽  
Well Differentiated ◽  
Sexual Processes ◽  
Open Question

SUMMARYThe commonly held view that the kinetoplastida, and in particular trypanosomes, are asexual is largely derived from the principle that an organism is asexual until proved sexual. If the basis for this view is examined in detail, it largely arises from the lack of morphologically distinguishable gametes, the difficulties encountered in visualizing chromosomes and a few experiments, using drug-resistant stocks, in which no recombination between stocks could be demonstrated. While it is clear that these organisms are able to reproduce asexually, the existence of a sexual cycle was, until recently, an entirely open question. The early work strongly suggests that any sexual process (in the species examined extensively at the morphological level) does not involve classical well-differentiated gametes and so must involve fusion of morphologically very similar cells. These findings taken together with the inability to visualize chromosomes and thereby identify meiosis, mean that classical methods are unable to detect any sexual process even if it did occur. This review examines the evidence provided by the experimental approaches which have been applied recently to the question of kinetoplastid sexuality. These approaches include isoenzyme studies and the analysis of possible genetic exchange by the use of selective markers (e.g. drug resistance). The results which these techniques have produced make it clear that the kinetoplastid protozoans cannot be regarded as a totally asexual group of organisms.

scholarly journals Epidemiology of Plasmodium falciparum infection and drug resistance markers in Ota Area, Southwestern Nigeria

2019 ◽  
Vol Volume 12 ◽  
pp. 1941-1949 ◽  
Author(s):  
Grace Olasehinde ◽  
Ruth Diji-geske ◽  
Irawo Fadina ◽  
Damola Arogundade ◽  
Precious Darby ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Southwestern Nigeria ◽  
Resistance Markers

The molecular epidemiology and phylogeography of Trypanosoma cruzi and parallel research on Leishmania: looking back and to the future

Parasitology ◽  
2009 ◽  
Vol 136 (12) ◽  
pp. 1509-1528 ◽  
Author(s):  
M. A. MILES ◽  
M. S. LLEWELLYN ◽  
M. D. LEWIS ◽  
M. YEO ◽  
R. BALEELA ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Molecular Epidemiology ◽  
Chagas Disease ◽  
Genetic Exchange ◽  
Sand Fly ◽  
Ecological Niches ◽  
Enzyme Electrophoresis ◽  
Multilocus Enzyme Electrophoresis ◽  
Genetic Groups

SUMMARYTrypanosoma cruzi is the protozoan agent of Chagas disease, and the most important parasitic disease in Latin America. Protozoa of the genus Leishmania are global agents of visceral and cutaneous leishmaniasis, fatal and disfiguring diseases. In the 1970s multilocus enzyme electrophoresis demonstrated that T. cruzi is a heterogeneous complex. Six zymodemes were described, corresponding with currently recognized lineages, TcI and TcIIa-e – now defined by multiple genetic markers. Molecular epidemiology has substantially resolved the phylogeography and ecological niches of the T. cruzi lineages. Genetic hybridization has fundamentally influenced T. cruzi evolution and epidemiology of Chagas disease. Genetic exchange of T. cruzi in vitro involves fusion of diploids and genome erosion, producing aneuploid hybrids. Transgenic fluorescent clones are new tools to elucidate molecular genetics and phenotypic variation. We speculate that pericardial sequestration plays a role in pathogenesis. Multilocus sequence typing, microsatellites and, ultimately, comparative genomics are improving understanding of T. cruzi population genetics. Similarly, in Leishmania, genetic groups have been defined, including epidemiologically important hybrids; genetic exchange can occur in the sand fly vector. We describe the profound impact of this parallel research on genetic diversity of T. cruzi and Leishmania, in the context of epidemiology, taxonomy and disease control.

Nodulation of soybeans carrying the nodulation-restrictive gene, rj1, by an incompatible Rhizobium japonicum strain upon mixed inoculation with a compatible strain

1980 ◽  
Vol 26 (2) ◽  
pp. 179-182 ◽  
Author(s):  
T. E. Devine ◽  
L. D. Kuykendall ◽  
B. H. Breithaupt
Keyword(s):  
Drug Resistance ◽  
Genetic Change ◽  
Media Analysis ◽  
Sand Culture ◽  
Rhizobium Japonicum ◽  
Selective Media ◽  
Rhizobium Strains ◽  
Temporary Association ◽  
Resistance Markers ◽  
Japonicum Strain

The rj1 gene in soybeans prevents nodulation by most strains of Rhizobium japonicum. Several strains, however, are known to nodulate rj1 plants in vermiculite or sand culture. Pure broth cultures of one of these strains (61 NalR) and a strain producing the typical non-nodulating response with rj1 (I-110 ARS) were mixed and used as inoculum on Clark rj1 soybeans in a growth chamber experiment. Both strains carried drug resistance markers and were identified using selective media. Analysis of the nodules formed indicated that 32% of the nodules contained both strains, 36% contained only the usually non-nodulating strain I-110 ARS, and 32% contained the usually infective strain (61 NalR). These results indicate that under conditions of high inoculum density the roots of Clark rj1 plants did not distinguish between Rhizobium strains 61 NalR and I-110 ARS. Subsequent tests with Rhizobium isolates from the nodules containing only strain I-110 ARS indicated that these rhizobia had not undergone a permanent genetic change in nodulation potential but were infective only because of temporary association with strain 61 NalR.

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