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PubMed1984

Ixodid ticks on feral swine in Florida.

More than 99% of the 645 feral swine (Sus scrofa L.) in southern Florida harbored ixodid ticks. Dermacentor variabilis (American dog tick) was present on 99.6% of the swine and comprised 82.5% of the ticks collected. Amblyomma maculatum (Gulf Coast tick) occurred on 85.9% of the hosts and 17.4% of the collections were of this species. Amblyomma americanum (Lone Star tick) and Ixodes scapularis (Black-legged tick) were found infrequently and together constituted less than 0.1% of the ticks. Pigs were infested by 7-22 days of age and 95% carried ticks by 6 wk of age. Only adult ticks were found on swine from southern Florida, but immature stages of A. americanum were present from a small sample of swine from northern Florida. Each species had a different pattern of distribution on the feral swine. No Ornithodoros species were found among the 36,616 ticks collected from feral swine during this survey.

Animals↗
PubMed1992

[Natural foci of tick-borne encephalitis in the Slovak Republic and its relation to the natural ecosystem].

To evaluate the incidence of natural foci of tick-borne encephalitis in the Slovak Republic data of the hygiene service on the morbidity from tick-borne encephalitis during the period from 1961-1988 were used as well as data from the literature and results of the author's field studies on the incidence of the common tick. The main foci of tick-borne encephalitis are in the West Slovakian region, in the Záhorské lowland, in the Váh valley up to the distrikt of Povázská Bystrica, in the area of the Low Carpathian mountains, Tribec, Vtácnik, the Nitra and Hron hills, and Kovácov hills, in the Central Slovakian region in the Krupin hills and in the East Slovakian region in the Slovak karst and Slanské hills. The incidence of common ticks and foci of tick-borne encephalitis is linked to the original oak grove communities. In Slovakia the latter comprise hornbean and oak forests, oak groves and thermophile oak forests. Areas of original communities of beech woods and spruces which grow in higher altitudes do not provide favourable conditions for the development of the common tick. Rare foci of tick-borne encephalitis of a mountainous type found in Slovakia survive probably due to the extremely favourable microclimatic conditions in these areas. Also the hygrophilous communities of alders, moorlands and dry steppes, original as well as cultivated ones, are not suitable for the common tick. This is why ticks are not found in central, northern and northeastern Slovakia, in the Rye island and lowland along the Tisa river.(ABSTRACT TRUNCATED AT 250 WORDS)

Czechoslovakia↗
PubMed2006

Immune response of mice infested by Hyalomma dromedarii ticks infected with entomopathogenic nematodes.

In the present work, the total leucocytes count of infested mice with ticks Hyalomma dromedarii infected with nematodes showed significant increase than infested group with ticks only. The infested group of mice with ticks and infested mice with ticks and nematodes showed a markedly significant drop in the erythrocytes count. The results showed a highly significant decrease in Hb concentration, and HCT percentage for mice infested with ticks and a marked increase with ticks infected with nematodes. The results showed a significant decrease in level of IgG of mice infested with ticks, while in infested mice with ticks and nematodes, the IgG level increased to control level which might indicated that nematodes penetrate ticks that were feeding on mice through the thinner cuticle of engorging females. Differences in cytokines responses were observed between tick-infested and non-infested mice. Proinflammatory Thl T lymphocyte cytokines were suppressed and Th2 cytokines were enhanced for infestation with H. dromedarii. The data indicated a polarization of immune response towards Th2 lymphocytes.

Animals↗
PubMed1985

Effects of tick infestation on Boran (Bos indicus) cattle immunised against theileriosis in an endemic area of Kenya.

Boran (Bos indicus) heifers were immunised by infection with local Theileria parva parva, T p lawrencei and T mutans stocks and treated with parvaquone and later exposed to natural tick and tick-borne disease challenge in the Trans-Mara Division of Kenya. The Theileria species parasites in the challenge were maintained in African buffalo and cattle and the tick vectors were supported by several species of wild Bovidae and domestic livestock present in the area. Thirty immune cattle were observed for 30 weeks while grazing on a ranch in the Trans-Mara Division. Of these, 15 were immersed in toxaphene at weekly or twice-weekly intervals while 15 cattle remained without acaricide application. Cattle which became pregnant were withdrawn from the experiment. There was no evidence of any clinical tick-borne disease in either group of cattle during the experiment. Five species of ixodid ticks infested the cattle during the experiment and cattle which were not treated with acaricide had far more ticks. Rhipicephalus appendiculatus was the most abundant tick species, with a mean infestation of 46 adults per animal in the undipped cattle. This tick also appeared to be the cause of the observed reduction in weight gains. Major haematological parameters did not differ significantly between the groups. Behavioural studies showed that the undipped cattle spent less time grazing and ruminating. This study has shown that, at the expense of some loss in productivity, zebu cattle, immunised against ticks and theileriosis, can be kept despite tick infestation.

Animals↗
PubMed1980

Organ culture of Rhipicephalus appendiculatus with maturation of Theileria parva in tick salivary glands in vitro.

A technique is described for the organ culture of Rhipicephalus appendiculatus ticks. Whole, unfed adult ticks with the dorsal integument removed, known as backless tick explants, were cultured in enriched Leibovitz' L-15 medium in which they remained active for at least 32 days at 28 degrees C and 9 days at 36 degrees C. Development of Theileria parva, as demonstrated by methyl green-pyronin staining, occurred in the salivary glands of infected backless tick explants held for 8 days at 28 degrees C or 3 days at 36 degrees C. Maturation in vitro of T. parva in backless tick explants was compared with that in cultured excised salivary glands. After 3-7 days at 36 degrees C glands from backless tick explants and excised salivary glands showed similar numbers of infected acini per infected tick. However, after 12 days at 28 degrees C backless tick explants showed 20-30 times as many infected acini per infected tick as excised salivary glands, in two experiments. No assessment was made of degree of parasite maturity or infectivity. It was concluded that both organ culture techniques supported development in vitro of the salivary gland stages of T. parva, but the backless tick explant technique was simpler and gave generally better results than culture of excised salivary glands.

Animals↗
PubMed1981

Cutaneous hyperaemia elicited by larvae of the cattle tick, Boophilus microplus.

The responses of skin capillary blood flow (BF) to infestation by larvae of B. microplus have been determined using radioactive microspheres. Larvae were placed in gauze-covered rings glued to the closely clipped skin. In pilot experiments on three Brahman-cross calves which had prior exposure to ticks, BF measurements at intervals up to 25 h post-infestation revealed a continuing increase. 'High' rates of infestation (5000 larvae per ring) elicited up to an 80-fold increase in BF. In four Australian Illawarra Shorthorn (AIS) calves with prior exposure to ticks, BF had increased by 0.5 h post-infestation, it reached a peak at 24 h, and fell markedly by 48 and 75 h. In contrast, two AIS calves without prior tick exposure showed no significant increase in BF until 24 h and this increase continued until observations were terminated at 72 h. BF in the neck area (normally favoured by ticks) increased most in calves of highest resistance to ticks, but the flank area (normally unfavoured) showed no consistent difference in BF response between animals of different tick resistance. It is concluded that skin capillary hyperaemia is triggered by the host's immune response to larval attachment. Within the relatively narrow range of tick resistance in the present animals, the degree of hyperaemia was directly related to level of resistance to the tick in skin regions normally favoured by ticks and therefore it may play a role in determining resistance to ticks.

Animals↗
PubMed1995

Detection of spotted fever group rickettsiae in ticks and rodents by polymerase chain reaction technique in People's Republic of China.

The polymerase chain reaction (PCR) technique for amplification of genomic fragments of spotted fever group (SFG) rickettsiae directly from field samples of ticks, tick ova, tick larvae, tick faeces and organs of wild mice was employed for the first time in P.R. of China. Ticks and rodents were collected in Beijing and Heilongjiang, Hainan and Hebei Provinces. The PCR primers were designed from the DNA sequence encoding the 190 K protein of R. rickettsii for a 532 bp long product. Seven of ten tick samples, three of four tick ovum samples, one of two tick larva samples, four of seven tick faeces samples (the samples represented pools of several individuals), and two of twenty-seven wild mouse organs were found PCR-positive. In comparison with PCR assay, the haemolymph test gave similar but not so clear-cut results. PCR assay is recommended as a rapid, sensitive and convenient tool for the detection of SFG rickettsiae in endemic foci. The fact that tick faeces were found to certain extent PCR-positive for the presence of SFG rickettsiae is apparently the first report on this subject and contributes to the knowledge of the transmission of these micro-organisms in the nature.

Animals↗
PubMedDate not supplied

Determinants of tick-avoidance behaviors in an endemic area for Lyme disease.

BACKGROUND: Tick bite control is an important initiative to prevent Lyme disease and other tickborne infections. While several studies have demonstrated that knowledge and awareness of Lyme disease in endemic areas are good, none has evaluated the relative importance of knowledge with other attitudinal and health belief variables to determine motivators of preventive behavior. METHODS: We conducted a cross-sectional analysis of 304 commuter ferry passengers departing Martha's Vineyard Island, Massachusetts, in August 1992, to ascertain the prevalence of tick-avoidance behaviors among individuals from an endemic area of Lyme disease and to identify the knowledge, behavioral, and demographic variables that best determine precautionary behavior. RESULTS: Overall, survey respondents (n = 304) had very good knowledge of Lyme disease (73% items correct on a knowledge test), but only 59% of respondents reported limiting time in tick areas, 58% usually wore protective clothing, 40% wore tick repellent, and 66% usually performed tick checks. By stepwise linear regression analysis, determinants of tick-avoidance behaviors included perceiving the behavior's benefits as outweighing its inconvenience (P < .0001), having confidence in recognizing Lyme disease symptoms (P < .0004), believing that Lyme disease is a serious illness (P < .0009), and believing that the avoidance behavior is effective in reducing the risk of Lyme disease (P < .01). Younger respondents (P < .05) performed fewer avoidance behaviors. Visitors (P < .0001) performed fewer tick checks than residents. Having confidence that one could find a tick on oneself with a tick check also predicted performance (P < .008). Increased general knowledge about Lyme disease did not predict any protective behaviors. CONCLUSIONS: Precautionary behaviors were underperformed in an at-risk population despite good knowledge of Lyme disease symptoms and transmission. Instead, performance was related to confidence in finding a tick on oneself and a perception that a precaution's benefit outweighed its inconvenience and would adequately reduce risk for Lyme disease. These data have implications for Lyme disease prevention programs, which typically focus on enhancing general knowledge as a means toward disease reduction.

Adult↗
PubMed1996

Efficacy of pheromone-acaricide-impregnated tail-tag decoys for controlling the bont tick, Amblyomma hebraeum (Acari: Ixodidae), on cattle in Zimbabwe.

A large-scale field test using pheromone-acaricide-impregnated plastic tail-tag decoys demonstrated excellent efficacy of these devices for control of the bont tick, Amblyomma hebraeum, on cattle in Zimbabwe. The tail tags were impregnated with a mixture containing o-nitrophenol, methyl salicylate, 2,6-dichlorophenol and phenylacetaldehyde and one of three different acaricides (cyfluthrin, flumethrin or alphacypermethrin). o-Nitrophenol and methyl salicylate are components of the A. hebraeum attraction-aggregation-attachment pheromone, while 2,6-dichlorophenol and phenylacetaldehyde are proven attractants for this tick. Both o-nitrophenol and methyl salicylate were lost gradually from the tags over 12 and 14 week periods, respectively. In field trials, tick counts were compared between cattle that received tail tags either impregnated with pheromone mixture alone, cyfluthrin and pheromone mixture, flumethrin and pheromone mixture, alphacypermethrin and pheromone mixture or were left untreated. During the first 3 month trial period, control of adult bont ticks was 94.9% with cyfluthrin tail tags and 87.5% with flumethrin tail tags. In general, there was no significant difference in bont tick numbers on cattle without tags and those with tail tags containing pheromone only. When the trial was repeated for another 3 month period, control of bont ticks with tail tags containing cyfluthrin and flumethrin was 99.3 and 95.1%, respectively. However, control of bont ticks using alphacypermethrin was only 79.2%. Overall, retention of tail tags was excellent although some loss was encountered during the rainy season. In addition to controlling bont ticks, the tail tags provided moderate control of other tick species (Rhipicephalus evertsi evertsi, Rhipicephalus zambeziensis and Hyalomma spp.) simultaneously infesting cattle in the trials.

Animals↗
PubMed1992

The use of time-series analysis to forecast bont tick (Amblyomma hebraeum) infestations in Zimbabwe.

Studying the dynamics of tick infestations on cattle is an essential step in developing optimal strategies for tick control. Successful strategic tick control requires accurate predictions of when tick infestations will reach predetermined threshold levels. In the case of Amblyomma hebraeum, earlier work has shown that there is no consistent pattern of seasonal activity. This means that a statistical model for predicting A. hebraeum infestations cannot reliably use climatic factors as the only independent variables. An alternative method is to apply time-series, or auto-regressive moving-average (ARMA), analysis which uses only the past population patterns to predict future trends. This technique was applied to a data set consisting of 108 weekly tick counts of A. hebraeum (adult males, standard females, flat females and standard nymphs), conducted at an experimental station in southeastern Zimbabwe. The ability of the ARMA models to fit and predict actual tick infestations was judged using two sets of criteria. The first set focused on the goodness-of-fit, and used the adjusted R2 values, Q statistic and the Akaike Information Criteria. The second set of criteria measured the forecasting accuracy of an estimated equation, and consisted of regressing a 9-period forecast against an actual out-of-sample data set not used in the estimation process. The root mean square error of the forecast was also considered when comparing several models for the same data set. Using these criteria, the models estimated using the ARMA technique were judged to both fit and forecast with sufficient accuracy to warrant their use in strategic tick control. Although the success of using ARMA to forecast A. hebraeum is partly due to the non-seasonal behavior of the species, the results presented here suggest that it is worthwhile exploring the use of ARMA techniques to model the dynamics of other tick species. Where independent variables exert considerable influence on the dynamics of a tick species, these variables can be incorporated into an ARMA-style model.

Animals↗
PubMed1994

Tick ecology.

The availability and expediency of acaricides for the control of ticks, together with the development of vaccination procedures against tick-borne diseases as a matter of priority, initially preceded information gained from research on tick ecology. The establishment of acaricide resistance, the increasing cost of chemical control and the data on production loss as an integral part of tick infestation are factors which led to the incorporation of ecological principles into tick control. Continuing research on the life processes of ticks as well as on their interaction with hosts and the environment, initiated producer manipulation of acaricide application frequencies, habitat manipulation techniques and the use of host immunity which are important for the establishment of economically suitable strategies of tick control. The role of tick ecology in establishing these concepts and its influence on current tick research is examined.

Animals↗
PubMed2006

Ixodid ticks parasitizing Iberian red deer (Cervus elaphus hispanicus) and European wild boar (Sus scrofa) from Spain: geographical and temporal distribution.

Commercial hunting of Spanish wild ungulates has made them an important economic resource. Wild ungulates may have an important role in the maintenance of ixodid tick populations, and also as reservoirs of pathogens. We studied the ixodid ticks that parasitize Iberian red deer and European wild boar from Spain. Ixodid ticks (n=6,336) were collected from 431 Iberian red deer and 142 wild boar in different regions of Spain. We found 10 different ixodid tick species parasitizing Iberian red deer, mainly Hyalomma marginatum marginatum (63.7%), Rhipicephalus (Boophilus) annulatus (7.9%) and R. bursa (7.5%). R. (Boophilus) annulatus was only collected in the province of Cádiz (southern Spain). We found 8 ixodid tick species on the wild boar, mainly Hy. m. marginatum (68.7%), R. bursa (14.6%) and Dermacentor marginatus (9.3%). We found one adult Hy. marginatum rufipes and one adult Hy. anatolicum excavatum parasitizing wild boar from south-central Spain. Mean prevalence of ixodid ticks was 41.3+/-0.08% (n=475) and 31+/-0.09% (n=284) and intensity of parasitization was 13.9+/-0.2 (n=283) and 13.6+/-0.3 (n=130) ticks/animal for Iberian red deer and wild boar, respectively. Only 5 of the 13 ixodid tick species found were shared by Iberian red deer and wild boar. This finding could indicate a host preference when Iberian red deer and wild boar share common habitats. In both Iberian red deer and wild boar from south-central Spain the monthly relative frequencies of Hy. m. marginatum and R. bursa presented an inverse pattern. The highest Hy. m. marginatum relative frequencies coincided with the lowest R. bursa relative frequencies along the year. R. bursa and I. ricinus were present in areas from northern to southern Spain while Hyalomma sp. and D. marginatus were exclusively collected in the two southern thirds of Spain. Haemaphysalis sp. and D. reticulatus were collected in northern Spain. Hy. m. marginatum and R. bursa were present during the whole year in red deer and wild boar from south-central Spain, showing more than one life cycle per year. These results are important for understanding the role of wild ungulates in the maintenance of tick infestations and to improve tick control programmes.

Animals↗
PubMed2004

Biochemical perspectives on paralysis and other forms of toxicoses caused by ticks.

Tick toxicoses, of which paralysis is the most widespread and dominant form, are important elements of pathogenesis induced by ticks. Tick paralysis is the most widespread and dominant form of tick toxicoses. Non-paralytic forms of tick toxicoses do occur and evidence suggests that these forms of toxicoses are not evolutionary related. While functional significance has been suggested for tick toxins, the advantages for tick survival in general are not clear. This review considers the molecular nature of tick toxins, the possibility that tick toxins have originated more than once independently and whether these toxins could have unrecognized benign functions.

Amino Acid Sequence↗
PubMed1990

Methods currently used for the control of multi-host ticks: their validity and proposals for future control strategies.

Ticks have a world distribution and pest status reputation of hampering livestock production through transmission of fatal disease such as theileriosis, anaplasmosis, babesiosis, etc. and bites which cause blood loss, pain and other debilitating effects. Control of ticks is largely more effective on the host. The multi-host ticks spend most of the time off the host with short feeding periods of between four and ten days. Chemical control using dips or sprays has been the traditional method of attempting to kill these ticks during the infestation period. In many situations control, using acaricides, has been quite successful. This has been possible through correct timing of the ticks' seasonal activity and feeding periods to determine the application interval, and efficacy of the acaricides. However, the rising costs of acaricides have made it almost impossible to use these chemicals on a regular basis according to the pest problem. This is particularly true in many Third World tropical countries in which tick-associated problems are more pronounced. This has necessitated the search for alternative tick control methods on an integrated approach to pest management. For this reason, vaccination against ticks and breeding for host resistance against ticks are being studied in the hope that future control strategies will involve only the economically effective acaricide application in conjunction with these and other methods.

Animal Husbandry↗
PubMed1996

Seasonal dynamics of the Karoo paralysis tick (Ixodes rubicundus): a comparative study on Merino and Dorper sheep.

Karoo paralysis in South Africa is induced in livestock by feeding female Ixodes rubicundus ticks when infestation densities on hosts exceed certain critical levels. It has been shown previously that Angora goats are at a higher risk of being paralysed than Merino sheep, and such differences have been related to differences in feeding behaviour and spatial distribution of the two small-stock breeds. We hypothesized that differences in infestation densities with Karoo paralysis ticks would also occur between Merino and Dorper sheep breeds. A study was conducted under natural conditions in the south-western Free State, to compare infestation burdens of the two sheep breeds and also to investigate seasonal patterns and annual variations in variations in terms of rainfall and temperature. Ten animals of each breed ran free in an area with a known history of Karoo paralysis and were examined on an approximately fortnightly basis, from March 1992 to December 1995, to determine tick abundance. Differences between the two breeds were significant (P < 0.05) during 1992 and 1993, but not during 1994. During the first two years, peak abundance of ticks was reached earlier in Dorper than in Merino sheep, and it also reached higher levels in Dorper than in Merino sheep (mean = 17.9 and 7.3, respectively). In 1993, two Dorper, but no Merino sheep, were paralysed. Dorper sheep are clearly at a higher risk of being paralysed than are Merino sheep, and as such, they can serve as indicators of adult tick activity and hence of the time to commence prophylactic treatment. Differences between the two breeds are probably related to differences in grazing patterns. Marked variation in abundance and the time of onset of peak activity of I. rubicundus occurred over the years. Tick numbers were high in 1993 and 1995, but very low in 1992. In 1993, peak activity occurred earlier (April) than during the other years (June or July). These differences are related to differences in prevailing environmental conditions that influence tick activity in a complex manner. Heightened humidity and lower temperatures during the early stages of seasonal activity of the tick (April or May), normally result in peak abundance of ticks on hosts at that time.

Animals↗
PubMed1995

Infection rate of Ixodes ricinus ticks with Borrelia afzelii, Borrelia garinii, and Borrelia burgdorferi sensu stricto in Slovenia.

In spring 1993, Ixodes ricinus ticks were collected from six regions of Slovenia to determine their overall rate of infection with Borrelia burgdorferi sensu lato and to assess the frequency of individual species in these tick populations. Ticks were dissected and midgut tissue inoculated into modified Barbour-Stoenner-Kelly (BSK II) medium. Borrelia isolates were differentiated into separate species using species-specific polymerase chain reaction (PCR) primers and by large restriction fragment pattern (LRFP) analysis. Infected ticks were found in all six regions surveyed. Spirochaetes were isolated from 69 of 363 ticks (19%): the isolation rate from adult female ticks was 35% (23/66 ticks cultured), from adult male ticks 22% (20/91), and from nymphal ticks 13% (26/206). Determination of the species of 60 isolates revealed that 32 were Borrelia afzelii (53%), 20 were Borrelia garinii (33%), and 8 were Borrelia burgdorferi sensu stricto (13%). In the Ljubljana region Borrelia afzelii and Borrelia garinii predominated (43% and 40%, respectively), whereas Borrelia burgdorferi sensu stricto constituted only 17% of isolates. In three other regions of the country Borrelia afzelii was isolated exclusively, although the number of isolates investigated was small. This study demonstrates the presence of all three European species of Borrelia burgdorferi sensu lato within the Slovenian tick population and also within a geographic area of less than 100 m2.

Animals↗
PubMed2006

Ticks (Ixodidae) from passerine birds in the Carpathian region.

Birds have been found to be a reservoir host of borrelia. In order to assess the situation in Slovakia ticks were collected from a total of 3057 mist-netted, ringed and released passerine birds in two locations at 500 m (in 2001) and 1000 m (in 2003) above sea level in the Bukovské Vrchy Hills, part of the Carpathian region in the north-east of Slovakia. A total of 75 birds of 16 species were infested with subadult ticks of Ixodes ricinus species (prevalence of parasitization 5%). Sixty-two larvae from 31 birds of 9 species and 80 nymphs from 52 birds of 15 species were found. The highest intensity of parasitization was observed on blackbirds Turdus merula, song thrushes T. philomelos and dunnocks Prunella modularis. Six Ixodes ricinus adult ticks were found on humans working with birds, and one I. ricinus female tick on their dog. In ticks, the presence of Rickettsia sp., Coxiella burnetii, Borrelia burgdorferi sensu lato and members of the Anaplasmataceae and Piroplasmidae, were investigated by polymerase chain reaction, followed by sequence analysis. Rickettsia sp. was found in 1 nymph from the European robin Erithacus rubecula, in 3 adult ticks (1 male, 2 females) from humans and in the tick from the dog. The closely related Ehrlichia- like species "Schotti variant" was detected in 1 nymph from the song thrush. Borrelia afzelii was identified in 1 male and B. garinii in 1 female tick collected on humans. Ixodes ricinus was found to be the vector of a wide spectrum of tick-borne pathogens in a mountainous area of the Carpathians. Because of the low yield of ticks and pathogens the importance of birds as reservoir hosts is still poorly understood.

Animals↗
PubMed2005

The molecular and biological analysis of ixodid ticks histamine release factors.

We previously described a Dermacentor varibialis (DV) cDNA that encodes a ubiquitously expressed and tick saliva-secreted functional histamine release factor (HRF) homolog. In this study gene specific primers based on DVHRF open reading frame nucleotide sequence were utilized to amplify three orthologs, from the wood tick, D. andersoni (DA), the black legged tick, the southern cattle tick, Boophilus microplus (BM) and the lone star tick, Amblyomma americanum (AA). At nucleotide level, sequence comparisons revealed 98 89 and 84% similarity to DVHRF for DAHRF, AAHRF and BMHRF, respectively, while predicted polypeptide comparisons revealed 98, 96 and 91% similarity for DAHRF, AAHRF and BMHRF respectively. Phylogenetically, the tick HRF clade, while distinct (100% bootstrap value), is closely related to other arthropods, but distantly related to vertebrate and protozoan clades. Consistent with sequence similarity analysis, a DVHRF-specific northern blotting probe hybridized a approximately 900 base pair (bp) mRNA band on all RNA blots. Likewise a mouse polyclonal antibody to E. coli-expressed recombinant (r) DVHRF, cross-reacted baculovirus-expressed non-fusion rAAHRF, rDAHRF, and rBMHRF. As revealed by northern blotting analysis of larvae and nymph RNA, DVHRF mRNA is expressed in both immature and mature ticks indicating that its transcription is not developmentally regulated. Unlike rHRF/TCTP proteins of other organisms, the calcium-binding function may not be conserved for tick HRF homologs as revealed by the 45CaCl2+ overlay assay. Apparent global expression of DVHRF and its orthologs make this protein family an ideal target antigen for development of novel tick control strategies targeting multiple tick species.

Amino Acid Sequence↗