Babesia bovis: Transcriptional analysis of rRNA gene unit expression

Laughery, Jacob M.; Lau, Audrey O.T.; White, Stephen N.; Howell, Jeanne M.; Suárez, Carlos E.

doi:10.1016/j.exppara.2009.05.016

Cited by 9 publications

(6 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, parasites electroporated with the control pTf-pBS plasmid did not survive upon blasticidin selection ( Fig 3A ). Clonal cell lines were generated from the mixed parasite line Tf-hap2KO-gfp-bsd by flow cell sorting [ 37 , 38 ]. Clonal lines were evaluated by expression of GFP ( Fig 3B ).…”

Section: Resultsmentioning

confidence: 99%

The Babesia bovis hap2 gene is not required for blood stage replication, but expressed upon in vitro sexual stage induction

et al. 2017

Self Cite

View full text Add to dashboard Cite

Babesia bovis, is a tick borne apicomplexan parasite responsible for important cattle losses globally. Babesia parasites have a complex life cycle including asexual replication in the mammalian host and sexual reproduction in the tick vector. Novel control strategies aimed at limiting transmission of the parasite are needed, but transmission blocking vaccine candidates remain undefined. Expression of HAP2 has been recognized as critical for the fertilization of parasites in the Babesia-related Plasmodium, and is a leading candidate for a transmission blocking vaccine against malaria. Hereby we identified the B. bovis hap2 gene and demonstrated that it is widely conserved and differentially transcribed during development within the tick midgut, but not by blood stage parasites. The hap2 gene was disrupted by transfecting B. bovis with a plasmid containing the flanking regions of the hap2 gene and the GPF-BSD gene under the control of the ef-1α-B promoter. Comparison of in vitro growth between a hap2-KO B. bovis clonal line and its parental wild type strain showed that HAP2 is not required for the development of B. bovis in erythrocytes. However, xanthurenic acid-in vitro induction experiments of sexual stages of parasites recovered after tick transmission resulted in surface expression of HAP2 exclusively in sexual stage induced parasites. In addition, hap2-KO parasites were not able to develop such sexual stages as defined both by morphology and by expression of the B. bovis sexual marker genes 6-Cys A and B. Together, the data strongly suggests that tick midgut stage differential expression of hap2 is associated with the development of B. bovis sexual forms. Overall these studies are consistent with a role of HAP2 in tick stages of the parasite and suggest that HAP2 is a potential candidate for a transmission blocking vaccine against bovine babesiosis.

show abstract

Section: Resultsmentioning

confidence: 99%

The Babesia bovis hap2 gene is not required for blood stage replication, but expressed upon in vitro sexual stage induction

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…No consensus has yet been reached on the degree of variation within the 18S SSU rRNA or other genes that would define a species (Chae et al 1999; Gubbels et al 2000; Bhoora et al 2009). It has been suggested that multiple copies of the 18S SSU RNA could account for genetic variation within a species, such as the case for Plasmodium and Babesia, where differential expression of 18S rRNA occurs as a response to various host environments and life-cycle stages (Gunderson et al 1987; Chae et al 1999; Lau, 2009; Laughery et al 2009). It has been shown that 2 copies of the 18S gene exist in the genomes of T. annulata and T. parva and is as such probably conserved in all Theileria spp.…”

Section: Discussionmentioning

confidence: 99%

Diversity in the 18S SSU rRNA V4 hyper-variable region ofTheileriaspp. in Cape buffalo (Syncerus caffer) and cattle from southern Africa

et al. 2011

View full text Add to dashboard Cite

Sequence variation within the 18S SSU rRNA V4 hyper-variable region can affect the accuracy of real-time hybridization probe-based diagnostics for the detection of Theileria spp. infections. This is relevant for assays that use non-specific primers, such as the real-time hybridization assay for T. parva (Sibeko et al. 2008). To assess the effect of sequence variation on this test, the Theileria 18S gene from 62 buffalo and 49 cattle samples was cloned and *1000 clones sequenced. Twentysix genotypes were detected which included known and novel genotypes for the T. buffeli, T. mutans, T. taurotragi and T. velifera clades. A novel genotype related to T. sp. (sable) was also detected in 1 bovine sample. Theileria genotypic diversity was higher in buffalo compared to cattle. Polymorphism within the T. parva hyper-variable region was confirmed by aberrant real-time melting peaks and supported by sequencing of the S5 ribosomal gene. Analysis of the S5 gene suggests that this gene can be a marker for species differentiation. T. parva, T. sp. (buffalo) and T. sp. (bougasvlei) remain the only genotypes amplified by the primer set of the hybridization assay. Therefore, the 18S sequence diversity observed does not seem to affect the current real-time hybridization assay for T. parva.

show abstract

“…There is therefore no reason to postulate that the extensive genetic diversity observed is due to more than two 18S rRNA copies, as found in Babesia and Plasmodium (Gunderson et al 1987;Lau, 2009;Laughery et al 2009). The two gene copies are also conserved due to concerted evolution (Eickbush and Eickbush, 2007).…”

Section: Are Unique Genotypes Unique Species?mentioning

confidence: 99%

Investigating the diversity of the 18S SSU rRNA hyper-variable region of Theileria in cattle and Cape buffalo (Syncerus caffer) from southern Africa using a next generation sequencing approach

Mans

Pienaar

Ratabane

et al. 2016

Ticks and Tick-borne Diseases

View full text Add to dashboard Cite

Molecular classification and systematics of the Theileria is based on the analysis of the 18S rRNA gene. Reverse line blot or conventional sequencing approaches have disadvantages in the study of 18S rRNA diversity and a next-generation 454 sequencing approach was investigated. The 18S rRNA gene was amplified using RLB primers coupled to 96 unique sequence identifiers (MIDs). Theileria positive samples from African buffalo (672) and cattle (480) from southern Africa were combined in batches of 96 and sequenced using the GS Junior 454 sequencer to produce 825711 informative sequences. Sequences were extracted based on MIDs and analysed to identify Theileria genotypes. Genotypes observed in buffalo and cattle were confirmed in the current study, while no new genotypes were discovered.Genotypes showed specific geographic distributions, most probably linked with vector distributions. Host specificity of buffalo and cattle specific genotypes were confirmed and prevalence data as well as relative parasitemia trends indicate preference for different hosts.Mixed infections are common with African buffalo carrying more genotypes compared to cattle. Associative or incongruent co-infection profiles were observed between genotypes that may have implications for speciation and systematics: specifically that more Theileria species may exist in cattle and buffalo than currently recognized. Analysis of primers used for Theileria parva diagnostics indicate that no new genotypes will be amplified by the current primer sets confirming their specificity. Theileria parva SNP variants that occur in the 18S rRNA hypervariable region were confirmed. A next generation sequencing approach is useful in obtaining comprehensive knowledge regarding 18S rRNA diversity and prevalence for the Theileria, allowing for the assessment of systematics and diagnostic assays based on the 18S gene.Keywords: 18S SSU, Diversity, Next-generation sequencing, species, Theileria, Theileria parva 3 IntroductionThe Babesia and Theileria are part of the phylum Apicomplexa (Order Piroplasmorida) (Mans et al. 2015 A significant proportion of the systematic study of the Piroplasmorida comprise analysis of the 18S rRNA gene (Allsopp et al. 1994;Chae et al. 1999;Chansiri et al. 1999;Criado-Fornelio et al. 2004;Reichard et al. 2005;Criado et al. 2006;Altay et al. 2007;Bhoora et al. 2009). The reverse line blot (RLB) method (Gubbels et al. 1999), based on simultaneous detection of the 18S rRNA gene for various Babesia and Theileria species, has been extensively used for surveillance purposes (Georges et al. 2001; Almerìa et al. 2002;Oura et al. 2004;Nijhof et al. 2003Nijhof et al. , 2005Altay et al. 2007;M'ghirbi et al. 2008;Altay et al. 2008;Matjila et al. 2008;Oosthuizen et al. 2008; Almerìa et al. 2009;Salih et al. 2010;Yusufmia et al. 2010; Tomassone et al. 2012;Ceci et al. 2014;Githaka et al. 2014;Eygelaar et al. 2015;Njiiri et al. 2015). The method relies on the amplification of the V4 hypervariable region of the 18S rRNA gene, followed by hybridization t...

show abstract

Babesia bovis: Transcriptional analysis of rRNA gene unit expression

Cited by 9 publications

References 22 publications

The Babesia bovis hap2 gene is not required for blood stage replication, but expressed upon in vitro sexual stage induction

The Babesia bovis hap2 gene is not required for blood stage replication, but expressed upon in vitro sexual stage induction

Diversity in the 18S SSU rRNA V4 hyper-variable region ofTheileriaspp. in Cape buffalo (Syncerus caffer) and cattle from southern Africa

Investigating the diversity of the 18S SSU rRNA hyper-variable region of Theileria in cattle and Cape buffalo (Syncerus caffer) from southern Africa using a next generation sequencing approach

Contact Info

Product

Resources

About