Origins of amino acid transporter loci in trypanosomatid parasites

摘要: Large amino acid transporter gene families were identified from the genome sequences of three parasitic protists, Trypanosoma brucei, cruzi and Leishmania major. These genes encode molecular sensors external host environment for trypanosomatid cells are crucial to modulation expression as parasite passes through different life stages. This study provides a comprehensive phylogenetic account origins these genes, redefining each locus according positional criterion, integration phyletic identity with comparative order information. Each was individually specified by its surrounding associated homologs showing same position ('homoeologs') in other species, where available. Bayesian maximum likelihood phylogenies general agreement on systematic relationships confirmed several 'orthology sets' retained since divergence common ancestor. Reconciliation analysis quantified scale duplication loss, well identifying further apparent orthology sets, which lacked conservation genomic position. instances suggested substantial restructuring or transposition. Other analyses clear evolutionary rate changes post-duplication, effects concerted evolution within tandem arrays conversion events between syntenic loci. Despite their importance cell function development, repertoires AAT loci parasites relatively fluid both complement dosage. Some ubiquitous and, after an ancient origin transposition, originated descent ancestral trypanosomatid. However, reconciliation demonstrated that unilateral expansions number duplication, transposition duplicates otherwise conserved positions, differential patterns loss have produced largely customised idiosyncratic all species. Not least T. seems fewer has acquired novel complex mix transpositive duplication.