title: Sequence diversity and evolution of multigene families in Trypanosoma cruzi.
abstract: Several copies of genes belonging to three multigene families present in the genome of Trypanosoma cruzi were sequenced and comparatively analyzed across six different strains of the parasite belonging to the T. cruzi I lineage (Colombiana, Silvio X10 and Dm28c), the T. cruzi II lineage (Esmeraldo and JG) and a hybrid strain (CL Brener). For all three gene families analyzed, our results support the division in T. cruzi I and II lineages. Furthermore, in agreement with its hybrid nature, sequences derived from the CL Brener clone clustered together with T. cruzi II sequences as well as with a third group of sequences. Paralogous sequences encoding Amastin, an amastigote surface glycoprotein and TcAG48, an antigenic RNA binding protein, which are clustered in the parasite genome, present higher intragenomic variability in T. cruzi II and CL Brener strains, when compared to T. cruzi I strains. Paralogous sequences derived from the TcADC gene family, which encode various isoforms of adenylyl cyclases and are dispersed throughout the T. cruzi genome, exhibit similar degree of variability in all strains, except in the CL Brener strain, in which the sequences were more divergent. Several factors including mutation rates and gene conversion mechanisms, acting differently within the T. cruzi population, may contribute to create such distinct levels of sequence diversity in multigene families that are clustered in the T. cruzi genome.
authors.affiliation: Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Gustavo C
authors.initials: GC
authors.lastname: Cerqueira
authors.forename: Daniella C
authors.initials: DC
authors.lastname: Bartholomeu
authors.forename: Wanderson D
authors.initials: WD
authors.lastname: DaRocha
authors.forename: Lihua
authors.initials: L
authors.lastname: Hou
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Freitas-Silva
authors.forename: Carlos Renato
authors.initials: CR
authors.lastname: Machado
authors.forename: Najib M
authors.initials: NM
authors.lastname: El-Sayed
authors.forename: Santuza M R
authors.initials: SM
authors.lastname: Teixeira
mesh_terms: D000262:Adenylyl Cyclases / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D016000:Cluster Analysis; D016054:DNA, Protozoan / Q000235:genetics; D019143:Evolution, Molecular; D008562:Membrane Glycoproteins / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D010750:Phosphoproteins / Q000235:genetics; D010802:Phylogeny; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014349:Trypanosoma cruzi / Q000145:classification / Q000235:genetics*
chemical_list: D016054:DNA, Protozoan; C038790:GP72 antigen, Trypanosoma; D008562:Membrane Glycoproteins; D010750:Phosphoproteins; D015800:Protozoan Proteins; D016601:RNA-Binding Proteins; C088681:amastin protein, Trypanosoma cruzi; D000262:Adenylyl Cyclases