Oxidative stress impairs heme detoxification in the midgut of the cattle tick, Rhipicephalus (Boophilus) microplus

Citelli, Marta; Lara, Flávio Alves; Vaz, Itabajara da Silva; Oliveira, Pedro L.

doi:10.1016/j.molbiopara.2006.10.008

Cited by 49 publications

(34 citation statements)

References 47 publications

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“…Oviposition was reduced and eggs were somewhat brown in color (Fig. 7), which is consistent with previous studies demonstrating that oxidative stress reduced egg-laying in Rhipicephalus microplus (Citelli et al 2007). No differences in hatching rate were noted between control and experimental groups.…”

Section: Resultssupporting

confidence: 92%

Transcriptional activation of antioxidants may compensate for selenoprotein deficiencies in Amblyomma maculatum (Acari: Ixodidae) injected with selK‐ or selM‐dsRNA

Adamson

Browning

Singh

et al. 2014

Insect Molecular Biology

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The Gulf-Coast tick, Amblyomma maculatum, possesses an elaborate set of selenoprotein, which prevent the deleterious effects from oxidative stress that occur during feeding. In the current work, we examined the role of Selenoprotein K (SelK) and Selenoprotein M (SelM) in feeding A. maculatum by bioinformatics, transcriptional gene expression, RNA interference and antioxidant assays. The transcriptional expression of SelK does not vary significantly in salivary glands or midguts throughout the blood meal. However, there is a 58-fold increase in transcript levels of SelM in tick midguts. Ticks injected with selK-dsRNA or selM-dsRNA did not reveal any observable differences in egg viability but oviposition was reduced. Surprisingly, salivary antioxidant activity was higher in selenoprotein knockouts compared to controls, which is likely due to compensatory transcriptional expression of genes involved in combating reactive oxygen species. In fact, RT-qPCR data suggest the transcriptional expression of catalase increased in ticks injected with selM-dsRNA. Additionally, the transcriptional expression of selN decreased ~90% in both SelK/SelM knockdowns.

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Section: Resultssupporting

confidence: 92%

Transcriptional activation of antioxidants may compensate for selenoprotein deficiencies in Amblyomma maculatum (Acari: Ixodidae) injected with selK‐ or selM‐dsRNA

Adamson

Browning

Singh

et al. 2014

Insect Molecular Biology

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“…While the functional role of additional G6PDH transcripts in R. microplus is presently unclear, it is plausible that engorgement induces the elevated expression of certain G6PDH isoforms in adult females to aid in the tolerance of feeding-induced oxidative stress by enabling an increase in NADPH production. Citelli et al (2007) recently demonstrated that oxidative stress impairs the heme detoxification process in R. microplus. The oxidative stress was induced in their study by inhibiting the activity of catalase resulting in an increase of hydrogen peroxide, considered a reactive oxygen species.…”

Section: Discussionmentioning

confidence: 99%

Multiple transcripts encode glucose 6-phosphate dehydrogenase in the southern cattle tick, Rhipicephalus (Boophilus) microplus

2010

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Glucose 6-phosphate dehydrogenase (G6PDH) is an enzyme that plays a critical role in the production of NADPH. Here we describe the identification of four transcripts (G6PDH-A, -B, -C, and -D) that putatively encode the enzyme in the southern cattle tick, Rhipicephalus (Boophilus) microplus. The genomic DNA that is spliced to produce G6PDH-A and -B is 8,600-9,000 bases in length and comprises 12 exons. Comparison of the R. microplus G6PDH gene structure with those available from insects and mammals revealed that the tick gene is most like that of humans. Detection of the four transcripts was evaluated by quantitative RT-PCR using template from larvae, unfed adult females and males, salivary gland tissues from 2- to 3-day-fed adult females and males, and salivary gland tissue of 4- to 5-day-fed adult females. The G6PDH-A and -C transcripts were present in all templates, and both displayed induced expression in salivary gland tissue of fed, adult females but not matched males. The G6PDH-D transcript was detected only in unfed adults and in larvae, a stage in which it was most abundant relative to the other three transcripts. The G6PDH-B transcript, while detectable in all templates, was of low copy number suggesting it is a rare transcript. Induced expression of G6PDH-A and G6PDH-C in fed females may play a role in the tolerance of oxidative stress that is induced upon feeding, and the transcript abundance in fed females may be a function of bloodmeal volume and the time adult females spend on the host relative to adult males.

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“…It has been suggested that digested blood is a source of oxidative stress as heme, a prooxidant, is released following hemolysis (Citelli et al, 2007). Glutathione S-transferases or GSTs (Contig 8822, Contig 336 and Contig 706) and cytochrome P450 enzymes (Contig 894, U92732.1 and CV443756) were identified that were up-regulated in gut tissues (Supplementary Table S4).…”

Section: (2004)mentioning

confidence: 99%

Gene expression profiling of adult female tissues in feeding Rhipicephalus microplus cattle ticks

Stutzer

Zyl

Olivier

et al. 2013

International Journal for Parasitology

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The southern cattle tick, Rhipicephalus microplus, is an economically important pest, especially for resource-poor countries, both as a highly adaptive invasive species and prominent vector of disease.The increasing prevalence of resistance to chemical acaricides and variable efficacy of current tick vaccine candidates highlight the need for more effective control methods. In the absence of a fully annotated genome, the wealth of available expressed sequence tag (EST) sequence data for this species presents a unique opportunity to study the genes that are expressed in tissues involved in blood meal acquisition, digestion and reproduction during feeding. Utilizing a custom oligonucleotide microarray designed from available singletons (BmiGI Version 2.1) and EST sequences of R. microplus, the expression profiles in feeding adult female midgut, salivary glands and ovarian tissues were compared. From 13,456 assembled transcripts, 588 genes expressed in all three tissues were identified from fed adult females 20 days post infestation. The greatest complement of genes relate to translation and protein turnover. Additionally, a number of unique transcripts were identified for each tissue that relate well to their respective physiological/biological function/role(s). These transcripts include secreted anti-hemostatics and defense proteins from the salivary glands for acquisition of a blood meal, proteases as well as enzymes and transporters for digestion and nutrient acquisition from ingested blood in the midgut, and finally proteins and associated factors involved in DNA replication and cell-cycle control for oogenesis in the ovaries. Comparative analyses of adult female tissues during feeding enabled the identification of a catalogue of transcripts that may be essential for successful feeding and reproduction in the cattle tick, R. microplus. Future studies will increase our understanding of basic tick biology, allowing the identification of shared proteins/pathways among different tissues that may offer novel targets for the development of new tick control strategies.

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Oxidative stress impairs heme detoxification in the midgut of the cattle tick, Rhipicephalus (Boophilus) microplus

Cited by 49 publications

References 47 publications

Transcriptional activation of antioxidants may compensate for selenoprotein deficiencies in Amblyomma maculatum (Acari: Ixodidae) injected with selK‐ or selM‐dsRNA

Transcriptional activation of antioxidants may compensate for selenoprotein deficiencies in Amblyomma maculatum (Acari: Ixodidae) injected with selK‐ or selM‐dsRNA

Multiple transcripts encode glucose 6-phosphate dehydrogenase in the southern cattle tick, Rhipicephalus (Boophilus) microplus

Gene expression profiling of adult female tissues in feeding Rhipicephalus microplus cattle ticks

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