Ticks are a significant, worldwide danger to livestock and human health.  They transmit a variety of viruses and bacteria, many of which are capable of infecting both animals and humans.  Examples of tick borne diseases now of concern in the United States are Lyme disease, Rocky Mountain spotted fever, and cattle fever.  There are many other, foreign tick borne diseases that could seriously affect American agriculture or public health should they be introduced; these include several hemorrhagic viruses (e.g., Crimean-Congo, Omsk, Kyasanur Forest) officially classed as potential biological warfare agents.  Ticks are difficult to control because they are increasingly resistant to pesticides, infest a variety of wild animals, and are long-lived.  Using the methods of molecular analysis to understand how genes in ticks control such things as pesticide resistance or susceptibility to pathogens may be the most promising strategy for controlling them.  On February 5, National Program 104 convened a one day workshop on tick genomics at The Institute for Genome Research (TIGR), Rockville, Maryland.  The purpose was to search for a consensus on the future direction work should take.  Participants included representatives from ARS, the National Institutes of Health, the International Livestock Research Institute and several universities.  TIGR's generous sponsorship of the meeting was greatly appreciated.

Each of the workshop participants, all of whom were actively working on tick molecular biology, briefly summarized his or her group's recent research.  Much of the afternoon was devoted to discussion.  All agreed that the very little known about tick genomics or proteomics is hindering the development of new vaccines and classes of acaricides.  All also agreed that the entire genome of at least one species should be sequenced; no life form related to ticks is being undertaken and a wealth of basic information could be expected.  The following were cited as potential impediments to proceeding with full genome sequencing:

• the genome, at one gigabase, with large introns, will cost $20-40 million to sequence
• lack of appreciation by funding agencies for the role ticks play in disease transmission
• lack of leadership

Because of the expense, it may be unrealistic to attempt to sequence fully more than one species, but there were strong constituencies for several important genera, including Boophilus, Dermacentor, Ixodes and Rhipicephalus.  Many felt that a species that vectors both human and animal diseases would be the best choice. The group concurred on the following intermediate goals:

• establish a network for sharing information
• plan a policy forum for decision makers at the National Academy of Sciences
• publish a "white paper" detailing goals and strategy
• plan an international scientific meeting for sharing data on tick genome
• select species to be sequenced
• put together a consortium of funding agencies

In the meantime, the two ARS units doing tick work - the Tick Research Unit, Kerrville, Texas and the Animal Diseases Research Unit, Pullman, Washington - will continue to concentrate on construction of bacterial artificial chromosome (BAC) and expressed sequence tag (EST) libraries for Boophilus microplus, the vector of cattle fever, and to increase communication with other members of the group.