title: Comparative genome analysis of three eukaryotic parasites with differing abilities to transform leukocytes reveals key mediators of Theileria-induced leukocyte transformation.
abstract: We sequenced the genome of Theileria orientalis, a tick-borne apicomplexan protozoan parasite of cattle. The focus of this study was a comparative genome analysis of T. orientalis relative to other highly pathogenic Theileria species, T. parva and T. annulata. T. parva and T. annulata induce transformation of infected cells of lymphocyte or macrophage/monocyte lineages; in contrast, T. orientalis does not induce uncontrolled proliferation of infected leukocytes and multiplies predominantly within infected erythrocytes. While synteny across homologous chromosomes of the three Theileria species was found to be well conserved overall, subtelomeric structures were found to differ substantially, as T. orientalis lacks the large tandemly arrayed subtelomere-encoded variable secreted protein-encoding gene family. Moreover, expansion of particular gene families by gene duplication was found in the genomes of the two transforming Theileria species, most notably, the TashAT/TpHN and Tar/Tpr gene families. Gene families that are present only in T. parva and T. annulata and not in T. orientalis, Babesia bovis, or Plasmodium were also identified. Identification of differences between the genome sequences of Theileria species with different abilities to transform and immortalize bovine leukocytes will provide insight into proteins and mechanisms that have evolved to induce and regulate this process. The T. orientalis genome database is available at http://totdb.czc.hokudai.ac.jp/.
authors.affiliation: Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Hayashida
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Hara
authors.forename: Takashi
authors.initials: T
authors.lastname: Abe
authors.forename: Chisato
authors.initials: C
authors.lastname: Yamasaki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Toyoda
authors.forename: Takehide
authors.initials: T
authors.lastname: Kosuge
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Sato
authors.forename: Shuichi
authors.initials: S
authors.lastname: Kawashima
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Katayama
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Wakaguri
authors.forename: Noboru
authors.initials: N
authors.lastname: Inoue
authors.forename: Keiichi
authors.initials: K
authors.lastname: Homma
authors.forename: Masahito
authors.initials: M
authors.lastname: Tada-Umezaki
authors.forename: Yukio
authors.initials: Y
authors.lastname: Yagi
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Fujii
authors.forename: Takuya
authors.initials: T
authors.lastname: Habara
authors.forename: Minoru
authors.initials: M
authors.lastname: Kanehisa
authors.forename: Hidemi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Kimihito
authors.initials: K
authors.lastname: Ito
authors.forename: Takashi
authors.initials: T
authors.lastname: Gojobori
authors.forename: Hideaki
authors.initials: H
authors.lastname: Sugawara
authors.forename: Tadashi
authors.initials: T
authors.lastname: Imanishi
authors.forename: William
authors.initials: W
authors.lastname: Weir
authors.forename: Malcolm
authors.initials: M
authors.lastname: Gardner
authors.forename: Arnab
authors.initials: A
authors.lastname: Pain
authors.forename: Brian
authors.initials: B
authors.lastname: Shiels
authors.forename: Masahira
authors.initials: M
authors.lastname: Hattori
authors.forename: Vishvanath
authors.initials: V
authors.lastname: Nene
authors.forename: Chihiro
authors.initials: C
authors.lastname: Sugimoto
mesh_terms: D000818:Animals; D002417:Cattle; D049109:Cell Proliferation; D018503:Genome, Protozoan; D007962:Leukocytes / Q000469:parasitology; D026801:Synteny; D016794:Theileria / Q000235:genetics* / Q000472:pathogenicity*; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D037521:Virulence Factors