%0 Journal Article
%T Comparative genomics of the pathogenic ciliate Ichthyophthirius multifiliis, its free-living relatives and a host species provide insights into adoption of a parasitic lifestyle and prospects for disease control
%A Robert S Coyne
%A Linda Hannick
%A Dhanasekaran Shanmugam
%A Jessica B Hostetler
%A Daniel Brami
%A Vinita S Joardar
%A Justin Johnson
%A Diana Radune
%A Irtisha Singh
%A Jonathan H Badger
%A Ujjwal Kumar
%A Milton Saier
%A Yufeng Wang
%A Hong Cai
%A Jianying Gu
%A Michael W Mather
%A Akhil B Vaidya
%A David E Wilkes
%A Vidyalakshmi Rajagopalan
%A David J Asai
%A Chad G Pearson
%A Robert C Findly
%A Harry W Dickerson
%A Martin Wu
%A Cindy Martens
%A Yves Van de Peer
%A David S Roos
%A Donna M Cassidy-Hanley
%A Theodore G Clark
%J Genome Biology
%D 2011
%I BioMed Central
%R 10.1186/gb-2011-12-10-r100
%X We report the sequencing, assembly and annotation of the Ich macronuclear genome. Compared with its free-living relative T. thermophila, the Ich genome is reduced approximately two-fold in length and gene density and three-fold in gene content. We analyzed in detail several gene classes with diverse functions in behavior, cellular function and host immunogenicity, including protein kinases, membrane transporters, proteases, surface antigens and cytoskeletal components and regulators. We also mapped by orthology Ich's metabolic pathways in comparison with other ciliates and a potential host organism, the zebrafish Danio rerio.Knowledge of the complete protein-coding and metabolic potential of Ich opens avenues for rational testing of therapeutic drugs that target functions essential to this parasite but not to its fish hosts. Also, a catalog of surface protein-encoding genes will facilitate development of more effective vaccines. The potential to use T. thermophila as a surrogate model offers promise toward controlling 'white spot' disease and understanding the adaptation to a parasitic lifestyle.The ciliates are an ancient and diverse phylogenetic group related to the largely parasitic apicomplexans, but consisting mostly of free-living heterotrophs. Some ciliates, however, have adopted a parasitic lifestyle. By far the most important of these is Ichthyophthirius multifiliis (which we will refer to by its common name of Ich), an endoparasite that causes white spot disease in freshwater fish [1,2]. With an extremely broad host-range, Ich is responsible for large-scale die-offs in natural populations and poses a significant threat to the growing worldwide aquaculture industry. Ich has a simple life cycle with no intermediate hosts (Figure 1). The free-swimming theront form invades the epidermis of susceptible fish, feeding on host tissue and growing up to 0.5 mm in diameter. Host-associated trophonts become visible as individual white spots for which this disease is n
%U http://genomebiology.com/2011/12/10/R100