التعرف على الفصائل والشجرة الوراثية للقراد الصلب (Rhipicephalus) بواسطة التحليل الجيني الجزيئي من عدة محافظات فلسطينية مختلفة
Date
2016-05-10
Authors
رائدة سالم احميدان طقاطقة
Raida Salim Ihmeidan Taqatqa
Journal Title
Journal ISSN
Volume Title
Publisher
AL-Quds University
جامعة القدس
جامعة القدس
Abstract
Ticks are obligate blood-sucking hematophagous ectoparasites of terrestrial vertebrates,
including amphibians, reptiles, birds, and mammals. Two general families of ticks are
recognized: Argasid (soft ticks) and Ixodid (hard ticks).The family Ixodidae of hard ticks is
divided into two groups based on morphological features: the Metastriata and the
Prostriata. In the Ixodidae family the genera Ixodes, Amblyomma, Dermacentor, and
Rhipicephalus are considered medically important. Among Rhipicephalus ticks, R.
sanguineus, R. turanicus and R. bursa, are the most common species in Palestine. All three
Rhipicephalus species are medically important vectors; therefore their accurate
identification is necessary. Morphological identification of these species is difficult,
especially when the specimens are damaged or engorged with blood or in on immature
stage.
The objectives of this study are to identify the most common hard-ticks species in
Palestine, to establish a molecular approach for discrimination between hard ticks species
that infest sheep, and dogs and to study the genetic variation within each species in
comparison to local and foreign hard ticks species. By identification of hard tick species,
the potential risk to animals as well as humans may be evaluated and thus more adequately
controlled.
A total of 351 hard ticks (Ixodidae) were collected from sheep, goats and dogs during
March to October 2014. Ticks were identified based on morphological features into two
main genus; Rhipicephalus (97.4%) and Haemaphysalis (2.6%). The ticks were further
identified down to the species level as following: R. sanguineus (79.2%), R. turanicus
(9.7%), R. bursa (3.4%), H. alderi (0.9%) and H. parva (1.6%). All tick samples were
identified by polymerase chain reaction (PCR) targeting the COX-1 gene followed by
RFLP using AluI restriction enzyme. A highly significant correlation was observed
between RFLP and microscopy identification (p= 0.01). Phylogenetic analysis based onCOX-1 genetic sequences showed four main clusters, R. sanguineus-like cluster, R.
turanicus -like cluster G1 and G2, and R. bursa-like cluster.
This study is the first of its kind to identify the hard tick species, using COX-1 gene
followed by RFLP as genetic marker. Distinction between the closely related
Rhipicephalus species: R. bursa, R. turanicus and R. sanguineus was successfully
accomplished.
Description
Keywords
الكيمياء الحيوية والاحياء الجزيئية , Biochemistry & Molecular Biology