Pienaar R

References (2)

Title : Sialotranscriptomics of Rhipicephalus zambeziensis reveals intricate expression profiles of secretory proteins and suggests tight temporal transcriptional regulation during blood-feeding - de Castro_2017_Parasit.Vectors_10_384
Author(s) : de Castro MH , de Klerk D , Pienaar R , Rees DJG , Mans BJ
Ref : Parasit Vectors , 10 :384 , 2017
Abstract : BACKGROUND: Ticks secrete a diverse mixture of secretory proteins into the host to evade its immune response and facilitate blood-feeding, making secretory proteins attractive targets for the production of recombinant anti-tick vaccines. The largely neglected tick species, Rhipicephalus zambeziensis, is an efficient vector of Theileria parva in southern Africa but its available sequence information is limited. Next generation sequencing has advanced sequence availability for ticks in recent years and has assisted the characterisation of secretory proteins. This study focused on the de novo assembly and annotation of the salivary gland transcriptome of R. zambeziensis and the temporal expression of secretory protein transcripts in female and male ticks, before the onset of feeding and during early and late feeding. RESULTS: The sialotranscriptome of R. zambeziensis yielded 23,631 transcripts from which 13,584 non-redundant proteins were predicted. Eighty-six percent of these contained a predicted start and stop codon and were estimated to be putatively full-length proteins. A fifth (2569) of the predicted proteins were annotated as putative secretory proteins and explained 52% of the expression in the transcriptome. Expression analyses revealed that 2832 transcripts were differentially expressed among feeding time points and 1209 between the tick sexes. The expression analyses further indicated that 57% of the annotated secretory protein transcripts were differentially expressed. Dynamic expression profiles of secretory protein transcripts were observed during feeding of female ticks. Whereby a number of transcripts were upregulated during early feeding, presumably for feeding site establishment and then during late feeding, 52% of these were downregulated, indicating that transcripts were required at specific feeding stages. This suggested that secretory proteins are under stringent transcriptional regulation that fine-tunes their expression in salivary glands during feeding. No open reading frames were predicted for 7947 transcripts. This class represented 17% of the differentially expressed transcripts, suggesting a potential transcriptional regulatory function of long non-coding RNA in tick blood-feeding. CONCLUSIONS: The assembled sialotranscriptome greatly expands the sequence availability of R. zambeziensis, assists in our understanding of the transcription of secretory proteins during blood-feeding and will be a valuable resource for future vaccine candidate selection.
ESTHER : de Castro_2017_Parasit.Vectors_10_384
PubMedSearch : de Castro_2017_Parasit.Vectors_10_384
PubMedID: 28797301
Gene_locus related to this paper: 9acar-g3mm97 , 9acar-a0a224z8q9 , 9acar-a0a224ygk6 , rhiap-a0a131ygg0

Title : De novo assembly and annotation of the salivary gland transcriptome of Rhipicephalus appendiculatus male and female ticks during blood feeding - de Castro_2016_Ticks.Tick.Borne.Dis_7_536
Author(s) : de Castro MH , de Klerk D , Pienaar R , Latif AA , Rees DJ , Mans BJ
Ref : Ticks Tick Borne Dis , 7 :536 , 2016
Abstract : Tick secretory proteins modulate haemostasis, inflammation and immune responses of the host and are attractive recombinant anti-tick vaccine candidates. Yet, many of the proteins have not been characterised due to the limited sequence availability for ticks and other arthropods for homology-based annotation. To address this limitation, we sequenced the salivary glands of the economically important adult male and female Rhipicephalus appendiculatus ticks during feeding. The quality-filtered Illumina sequencing reads were de novo assembled to generate a R. appendiculatus sialotranscriptome of 21,410 transcripts. A non-redundant set of 12,761 R. appendiculatus proteins was predicted from the transcripts, including 2134 putative secretory and 8237 putative housekeeping proteins. Secretory proteins accounted for most of the expression in the salivary gland transcriptome (63%). Of the secretory protein class, the Glycine-rich superfamily contributed 66% and the Lipocalin family 12% of the transcriptome expression. Differential expression analysis identified 1758 female and 2346 male up-regulated transcripts, suggesting varying blood-feeding mechanisms employed between female and male ticks. The sialotranscriptome assembled in this work, greatly improves on the sequence information available for R. appendiculatus and is a valuable resource for potential future vaccine candidate selection.
ESTHER : de Castro_2016_Ticks.Tick.Borne.Dis_7_536
PubMedSearch : de Castro_2016_Ticks.Tick.Borne.Dis_7_536
PubMedID: 26830274
Gene_locus related to this paper: 9acar-g3mm97 , rhiap-a0a131z123 , rhiap-a0a131yiz1 , rhiap-a0a131yft0 , rhiap-a0a131ygg0