Conserved organization of genes in trypanosomatids1Note: The GenBank accession numbers are: AF031925 (T. brucei: 5′ THT-flanking region), AF031926 and AF032098 (T. brucei: 3′ THT-flanking region), AF031927 (CosTcr1 clone of T. cruzi: 3′ TcrHT-flanking region), AF031928 (CosTcr2 clone of T. cruzi: ORF1 downstream of the retrotransposon), AF032096 (T. congolense: unit repeat containing the TcoHT1 gene) and AF032097 (T. congolense: unit repeat containing the TcoHT2 gene).1
التفاصيل البيبلوغرافية
العنوان:
Conserved organization of genes in trypanosomatids1Note: The GenBank accession numbers are: AF031925 (T. brucei: 5′ THT-flanking region), AF031926 and AF032098 (T. brucei: 3′ THT-flanking region), AF031927 (CosTcr1 clone of T. cruzi: 3′ TcrHT-flanking region), AF031928 (CosTcr2 clone of T. cruzi: ORF1 downstream of the retrotransposon), AF032096 (T. congolense: unit repeat containing the TcoHT1 gene) and AF032097 (T. congolense: unit repeat containing the TcoHT2 gene).1
Trypanosomatids are unicellular protozoan parasites which constitute some of the most primitive eukaryotes. Leishmania spp, Trypanosoma cruzi and members of the Trypanosoma brucei group, which cause human diseases, are the most studied representatives of this large family. Here we report a comparative analysis of a large genomic region containing glucose transporter genes in three Salivarian trypanosomes (T. brucei, T. congolense and T. vivax), T. cruzi and Leishmania donovani. In T. brucei, the 8 kb (upstream) and 14 kb (downstream) regions flanking the glucose transporter genes cluster contain two and six new genes, respectively, six of them encoding proteins homologous to known eukaryotic proteins (phosphatidylinositol 3 kinase, ribosomal protein S12, DNAJ and three small G-proteins--Rab1, YPT6 and ARL3). This gene organization is identical in T. brucei, T. congolense and T. vivax suggesting that Salivarian trypanosomes have a high level of conservation in gene organization. In T. cruzi and Leishmania, the overall organization of this cluster is conserved, with insertion of additional genes when compared with T. brucei. Phylogenetic reconstitution based on glucose transporters is in accord with the monophyly of the genus Trypanosoma and the early separation of T. vivax within Salivarian trypanosomes. On the basis of gene organization, biochemical characteristics of isoforms and phylogeny, we discuss the genesis of the glucose transporter multigene family in Salivarian trypanosomes.
