| Haemaphysalis longicornis are one of the extremely widespread and important suck-blooding ectoparasites, which mainly infested many vertebrates, such as cattle,sheep and so on. It can act as vectors of many vertebrate important pathogens of human and animals, for example virus, rickettsia, leptospira, bacteria, protozoa, mycoplasma, chlamydia, and hazard the husbandry severely.The studies of H. longicornis in northern China were major basic of observation under laboratory conditions, the cDNA library of eggs of H. longicornis were construced and amplified. Some genes was screened and cloned using immunological mathed. The major resultes were presented as following:1. Three hosts were needed in one generation of H.longicornis. The duration of engorged female adults to next generation was 101~148 days. The hard tick feeding phase is generally characterized into the preparatory phase, slow feeding phase and rapid feeding phase. The body weight and egg mass of this strain was significantly different for differently fed (P<0.01), the more the weight, the more the egg mass, the weight of engorged adult female fed on the rabbit is bigger than on the sheep. When the temperature was increased at a fixed range, the molting time of larva and nymph became reduced, the oviposition period of adults and the incubation period of eggs was also reduced. The fecundity of an adult was no significantly changes at the range of 16℃to 30℃. The engorged ticks couldn't live under 4℃degree and up 45℃degree, the developmental cycle of the strain was extended under 16℃degree. The fecundity was increased when the temperature was increased, the developmental cycle were extended at the relative humidity below 70%. The result showed that male tick can help female tick to feed. Some of self-factors and external factors can influence the life cycle of H. longicornis.2. Three hosts were also needed in one generation of Parthenogenesis population of H.longicornis. The duration of engorged female adults to next generation was 106~153 days. The weights of prefeeding larva and nymph were not significantly different from those of the control group (P>0.05), but the weight of prefeeding adult female was significantly less than that of the control group (P<0.05), the weights of fed ticks were extremely different from those of the control group (P<0.01). In addition, the weight of engorged adult female is 108.46±19.72 times than hungered adult female, which was also extremely different from that of the control group (P<0.01). There was a highly significant correlation between the engorgement body weight of female and the egg mass (r=0.8970, P<0.01). The reproductive efficiency index (REI) and reproductive fitness index (RFI) in female was 6.76 and 6.29 respectively. The life cycle of H. longicornis does not change along with seasons. It is indicated that this stain of ticks belonged to parthenogenesis population of H. longicornis.3. By comparision to threen serum used immunodiffusion test, the result show that the serum titer of extrolymphoid and interolymphoid was 1:128,1:64, respectively; the serum titer by ticks biting rabbit was 1:8. But the serum titer of the control is 0. Immune cross-reaction were exist in the antibody of eggs, larvas, nymphs and adults. The serum by interolymphy immuing is adapted to immunological screening.4. Resulting in a primary cDNA library and amplified library with a size of 4.0×106 pfu and 9.07×1010 pfu/ml respectively. A cDNA encoding follistatin-related protein was cloned from the expression library. The library was proved a good quality one by all the control tests.5. Using immunological screening method to screen the gene from the cDNA library, 12 new clones was proved. Three of the 12 new clones were further proved from H. longicornis tick by PCR analysis, sequencing and sequence analysis of Genbank blast, fouth of the 12 new clones is Panagrellus redivivus heat shock protein 70-C mRNA,DNA for rRNA tandem repeat unit,sensor histidine kinase and Hypothetical protein, respectively. The others had no matches to any sequence reported in the database.
|
PDF Full Text Request