Comparative karyotyping as a tool for genome structure analysis of Trypanosoma cruzi

Trypanosomatid comparative genomics: contributions to the study of parasite biology and different parasitic diseases

“…Prior to this knowledge, the choice of the clone CL Brener, initially classified as a member of sub-group IIe, was based on five characteristics: (1) it was isolated from the domiciliary vector Triatoma infestans , (2) its pattern of infectivity in mice was very well known, (3) it had preferential tropism for heart and muscle cells, (4) it showed a clear acute phase in accidentally infected humans, and (5) it was susceptible to drugs used to treat Chagas disease (Zingales et al , 1997). In addition, several genomic studies had previously used this strain for karyotype analyses (Branche et al , 2006) and the generation of physical maps and ESTs from all three stages of the parasite life cycle (Cano et al , 1995; Henriksson et al , 1995; Brandão et al , 1997; Verdun et al , 1998; Porcel et al , 2000; Cerqueira et al , 2005). …”

“…Four years later, based on synteny maps for the T. brucei chromosomes, Weatherly et al (2009) assembled the T. cruzi contigs and scaffolds initially in 11 pairs of homologous “ T. brucei -like” chromosomes and, ultimately, in 41 T. cruzi chromosomes. Since trypanosomatid chromosomes do not condensate during mitosis and are therefore not visualized in metaphasic cells the predicted number of T. cruzi chromosomes was based on studies of pulsed-field gel electrophoresis (PFGE) analyses (Branche et al , 2006), which turned out to be similar to the number of assembled chromosomes. As mentioned above, the genome organization in T. cruzi is largely syntenic with the other Tri-Tryp ( T. brucei and L. major ) genomes, with most species-specific genes, such as surface protein gene families, occurring in internal and subtelomeric regions of non-syntenic chromosome (El-Sayed et al , 2005a).…”

“…, smaller than the CL Brener genome. Indeed, smaller genomes seems to be a general feature of T. cruzi I strains (Branche et al , 2006; Franzén et al , 2011). As expected, the architectures of the two genomes were very similar, with highly conserved syntenic regions corresponding to the gene-dense “core” of the coding regions organized for long polycistronic transcription.…”

Trypanosoma cruzi: diversidade, relações filogenéticas e padrões ecogeográficos de isolados silvestres.

“…Estudos realizados com outros marcadores moleculares, incluindo padrões de RAPD (Brisse et al, 2000a,b), seqüências do gene SSUrDNA (Brisse et al, 2001) e análises de um grande número de loci de isoenzimas (Breniere et al, 2003) (Barrett et al, 1980;Miles et al, 1981a;Povoa et al, 1984;Gaunt e MIles, 2000;Yeo et al, 2005;Fernandes et al, 1998a,b;Zingales et al, 1999;Freitas et al, 2006;Ceballos et al, 2006;Cardinal et al, 2008 Sturm et al, 2003;Westenberger et al, 2005Westenberger et al, , 2006Freitas et al, 2006), Cariotipagem (Henriksson et al, 2002;Brisse et al, 2003;Pedroso et al, 2003Pedroso et al, , 2007Branche et al, 2006), polimorfismo de loci de microssatélite (Machado e Ayala, 2001;Freitas et al, 2006) etc.…”

“…Outro estudo revelou que populações híbridas possuem diferenças nos tamanhos dos cromossomos homólogos em comparação as linhagens não-híbridas, demonstrando a importância dos cromossomos na identificação de grupos evolutivos principalmente as linhagens híbridas (Pedroso et al, 2002) T. cruzi IIe CL Berner (cepa de referência do projeto genoma) e duas cepas T. cruzi I (Sylvio X10/7 e CAI/72 foram utilizados em um estudo comparativo de seus cariótipos. Grandes diferenças de tamanho em cromossomos homólogos foram observados, indicando grandes arranjos cromossômicos (Branche et al, 2006). Outro estudo recente, demonstra através de uma análise numérica dos padrões cromossômicos que o grupo Z3B (TCIIa) forma um outro grupo distinto as demais linhagens (Pedroso et al, 2007).…”