Sequencing the genome tick deer (Ixodes scapularis) should help in the fight against borne by him diseases, including Lyme disease – informs Nature Communications.
The ongoing 10 years project completed an international research team (93 authors from 46 units) under the leadership of scientists from Purdue University (USA).
Ixodes scapularis is the first species of tick, whose genome was sequenced – the study proved to be more difficult than in the case of carrying the malaria mosquito, and same ticks were considered less dangerous. – The genome ushers in a new era in the study of ticks – said the lead author, Professor. Catherine Hill from Purdue University.
Ticks transmit more diseases and parasites than any other arthropod, among them the devastating organism Lyme disease, which according to estimates by the Centers for Disease Control falls annually more than 300 000 Americans (only every tenth case is properly diagnosed and reported).
because of these diseases (anaplasmosis, babesiosis, Powassan virus, encephalitis) die every year thousands of people and animals. To suck the blood of the host, ticks pierce his skin and bring to a wound in their saliva, which can be infected.
The study covered both the genes and proteins that facilitate parasitism and disease transmission. This should help in the development of new drugs and vaccines.
We also managed to learn more about the unique aspects of the biology of the tick. Its saliva contains substances bactericidal, analgesic, anticoagulant and immunosuppressive, which allow it to quietly suck blood from the host, even for weeks. These substances are thousands (while blood mosquito contains hundreds of them), which allows the use of a variety of hosts.
The researchers also identified genes allowing ticks to produce new carapace during feeding, so you can zoom in even a hundred times as well those that facilitate feeding on the blood contains large amounts of iron (excess iron is toxic).
Another unique feature of the ticks are enzymes, so that they can “beat” insecticides.
One of the the biggest challenges for the researchers was the complexity of the genome tick – the largest genomes of arthropods, which so far sequenced. Interestingly, about 70 per cent. genome are the genes repeated frequently mutated. Perhaps the different copies of the same gene are slightly different action to facilitate arachnids survival.
By the way, we were able to explain that ticks Ixodes scapularis occurring in the south and north of the United States do not differ genetically sufficiently to be considered as two distinct species.
however, as more cases of Lyme disease occurs in the north, probably a genetic trait of local ticks is important for the transmission of the disease.
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