title: Gene discovery in the Entamoeba invadens genome.
abstract: Entamoeba invadens, a parasite of reptiles, is a model for the study of encystation by the human enteric pathogen Entamoeba histolytica, because E. invadens form cysts in axenic culture. With approximately 0.5-fold sequence coverage of the genome, we were able to get insights into E. invadens gene and genome features. Overall, the E. invadens genome displays many of the features that are emerging from ongoing genome sequencing efforts in E. histolytica. At the nucleotide level the E. invadens genome has on average 60% sequence identity with that of E. histolytica. The presence of introns in E. invadens was predicted with similar consensus (GTTTGT em leader A/TAG) sequences to those identified in E. histolytica and Entamoeba dispar. Sequences highly repeated in the genome of E. histolytica (rRNAs, tRNAs, CXXC-rich proteins, and Leu-rich repeat proteins) were found to be highly repeated in the E. invadens genome. Numerous proteins homologous to those implicated in amoebic virulence, (Gal/GalNAc lectins, amoebapores, and cysteine proteinases) and drug resistance (p-glycoproteins) were identified. Homologs of proteins involved in cell cycle, vesicular trafficking and signal transduction were identified, which may be involved in en/excystation and cell growth of E. invadens. Finally, multiple copies of a number of E. invadens genes coding for predicted enzymes involved in core metabolism and the targets of anti-amoebic drugs were identified.
authors.affiliation: Center for Bio/Molecular Science Naval Research Laboratory, Washington, DC 20375, USA.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.forename: John
authors.initials: J
authors.lastname: Samuelson
authors.forename: C Graham
authors.initials: CG
authors.lastname: Clark
authors.forename: Daniel
authors.initials: D
authors.lastname: Eichinger
authors.forename: Jaishree
authors.initials: J
authors.lastname: Paul
authors.forename: Katrina
authors.initials: K
authors.lastname: Van Dellen
authors.forename: Neil
authors.initials: N
authors.lastname: Hall
authors.forename: Iain
authors.initials: I
authors.lastname: Anderson
authors.forename: Brendan
authors.initials: B
authors.lastname: Loftus
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004275:DNA, Ribosomal / Q000032:analysis; D004747:Entamoeba / Q000235:genetics* / Q000302:isolation & purification; D017125:Genes, Protozoan; D018503:Genome, Protozoan; D007930:Leucine / Q000737:chemistry / Q000235:genetics; D020084:Long Interspersed Nucleotide Elements; D008969:Molecular Sequence Data; D010802:Phylogeny; D010957:Plasmids / Q000032:analysis; D015800:Protozoan Proteins / Q000032:analysis; D012343:RNA, Transfer / Q000032:analysis; D016415:Sequence Alignment
chemical_list: D004275:DNA, Ribosomal; D015800:Protozoan Proteins; D012343:RNA, Transfer; D007930:Leucine