Morbidity and Mortality Rates in East Coast Fever ( Theileria Parva Infection) and their Application to Drug Screening Procedures

Brocklesby, D.W.; Barnett, S. F.; Scott, G. R.

doi:10.1016/s0007-1935(17)43303-3

Cited by 148 publications

(24 citation statements)

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“…An important aspect of the mechanism is that turnover of chromosomes within a reproductively isolated, sexually reproducing population is more rapid than sequence homogenization of a multicopy family within genomes, resulting in concerted evolution at the population level, which has been called molecular drive (13). Since the T. parva Muguga, Boleni, and Uganda isolates are from widely separated geographical locations (8,26,30), it is reasonable to assume that they originate from reproductively isolated parasite populations. However, a successful genetic cross between T. parva Muguga and T. parva Uganda has been performed in the laboratory (35).…”

Section: Discussionmentioning

confidence: 99%

Concerted Evolution at a Multicopy Locus in the Protozoan Parasite Theileria parva: Extreme Divergence of Potential Protein-Coding Sequences†

Bishop

Musoke

Morzaria

et al. 1997

Molecular and Cellular Biology

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Concerted evolution of multicopy gene families in vertebrates is recognized as an important force in the generation of biological novelty but has not been documented for the multicopy genes of protozoa. A multicopy locus, Tpr, which consists of tandemly arrayed open reading frames (ORFs) containing several repeated elements has been described for Theileria parva. Herein we show that probes derived from the 5/N-terminal ends of ORFs in the genomic DNAs of T. parva Uganda (1,108 codons) and Boleni (699 codons) hybridized with multicopy sequences in homologous DNA but did not detect similar sequences in the DNA of 14 heterologous T. parva stocks and clones. The probe sequences were, however, protein coding according to predictive algorithms and codon usage. The 3/C-terminal ends of the Uganda and Boleni ORFs exhibited 75% similarity and identity, respectively, to the previously identified Tpr1 and Tpr2 repetitive elements of T. parva Muguga. Tpr1-homologous sequences were detected in two additional species of Theileria. Eight different Tpr1-homologous transcripts were present in piroplasm mRNA from a single T. parva Muguga-infected animal. The Tpr1 and Tpr2 amino acid sequences contained six predicted membrane-associated segments. The ratio of synonymous to nonsynonymous substitutions indicates that Tpr1 evolves like protein-encoding DNA. The previously determined nucleotide sequence of the gene encoding the p67 antigen is completely identical in T. parva Muguga, Boleni, and Uganda, including the third base in codons. The data suggest that concerted evolution can lead to the radical divergence of coding sequences and that this can be a mechanism for the generation of novel genes.

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Section: Discussionmentioning

confidence: 99%

Concerted Evolution at a Multicopy Locus in the Protozoan Parasite Theileria parva: Extreme Divergence of Potential Protein-Coding Sequences†

Bishop

Musoke

Morzaria

et al. 1997

Molecular and Cellular Biology

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“…The presence of T. parva DNA was demonstrated in field samples using the T. parva-specific real-time PCR assay as previously described (Sibeko et al, 2008). Two DNA samples from cattle-derived T. parva stocks, Muguga (Brocklesby et al, 1961) and Katete (Geysen, 2000), from Kenya and Zambia, respectively, were used as reference samples. Theileria parva (Schoonspruit), an isolate obtained from a bovine infected during the ECF epidemic in South Africa (Neitz, 1948), was also used for reference.…”

Section: Sample Collection and Screening Of T Parva-positive Samplesmentioning

confidence: 99%

Analyses of genes encoding Theileria parva p104 and polymorphic immunodominant molecule (PIM) reveal evidence of the presence of cattle-type alleles in the South African T. parva population

Sibeko

Collins

Oosthuizen

et al. 2011

Veterinary Parasitology

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Restriction fragment length polymorphism analysis of PCR products (PCR-RFLP) and sequencing of the variable region of the p104 and PIM genes was performed on samples obtained from South African T. parva parasites originating from cattle on farms with suspected theileriosis and from buffalo. p104 and PIM PCR-RFLP profiles similar to those of the T. parva Muguga stock, an isolate that causes ECF in Kenya, were obtained from three of seven cattle samples collected on a farm near Ladysmith in KwaZulu-Natal Province. Amino acid sequences of the p104 and PIM genes from two of these samples were almost identical to the T. parva Muguga p104 and PIM sequences.This result supports findings from a recent p67 study in which p67 alleles similar to those of the T.parva Muguga stock were identified from the same samples. While these results suggest the presence of a cattle-derived T. parva parasite, reports of cattle-to-cattle transmission could not be substantiated and ECF was not diagnosed on this farm. Although extensive diversity of p104 and PIM gene sequences from South African T. parva isolates was demonstrated, no sequences identical to known cattle-type p104 and PIM alleles were identified from any of the buffalo T. parva samples analyzed. 'Mixed' PIM alleles containing both cattle-and buffalo-type amino acid motifs were identified for the first time, and there appeared to be selection of cattle-type and 'mixed'-type PIM sequences in the cattle samples examined. Keywords:Theileria parva, p104, polymorphic immunodominant molecule (PIM), characterization, Corridor disease, East Coast fever 3 IntroductionCattle theileriosis caused by Theileria parva is a disease of major economic importance in eastern, central and parts of southern Africa (Young et al., 1988). Infections of cattle by T. parva parasites result in three recognized disease syndromes, East Coast fever (ECF), January disease and Corridor disease. The natural tick vectors of T. parva in South Africa are Rhipicephalus appendiculatus and R. zambeziensis (Lawrence et al., 1983), and, in the presence of T. parva-infected buffalo, the vector ticks can transmit the parasite to naïve cattle, resulting in Corridor disease outbreaks.Corridor disease remains important in South Africa where it is a controlled disease. et al., 2008). This finding is of concern to the cattle industry in South Africa, as Potgieter et al. (1988) showed that buffalo-derived T. parva parasites, causing Corridor disease, can be maintained by passage between cattle and the tick vector. The persistence of T. parva infections in cattle in South Africa could eventually result in the selection of T. parva parasites adapted to cattle. It remains a concern that ECF could re-emerge and therefore a serious need exists to establish if there are cattle-type T. parva parasites in buffalo in South Africa.Restriction fragment length polymorphism analyses of PCR products (PCR-RFLP) of T. parva antigen genes, PIM, p104, p150 and p67, have been used for characterization of T. parva stocks (Geysen et ...

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“…The first group of cattle were animals susceptible to theileriosis, seroMgically negative to 7'. parva (Muguga) (Brocklesby, Barnett and Scott, 1961)cell culture schizont antigen using the indirect fluorescent antibody test (Burri.dge and Kimber, 1972).…”

Section: Methodsmentioning

confidence: 99%

Theileriosis: The exposure of immunised cattle in aTheileria lawrencei enzootic area

Cunningham

Brown

Burridge

et al. 1974

Trop Anim Health Prod

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Morbidity and Mortality Rates in East Coast Fever ( Theileria Parva Infection) and their Application to Drug Screening Procedures

Cited by 148 publications

References 0 publications

Concerted Evolution at a Multicopy Locus in the Protozoan Parasite Theileria parva: Extreme Divergence of Potential Protein-Coding Sequences†

Concerted Evolution at a Multicopy Locus in the Protozoan Parasite Theileria parva: Extreme Divergence of Potential Protein-Coding Sequences†

Analyses of genes encoding Theileria parva p104 and polymorphic immunodominant molecule (PIM) reveal evidence of the presence of cattle-type alleles in the South African T. parva population

Theileriosis: The exposure of immunised cattle in aTheileria lawrencei enzootic area

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