Cabrine-Santos Marlene, Ferreira Keila A M, Tosi Luiz R O, Lages-Silva Eliane, Ramirez Luis Eduardo, Pedrosa André Luiz
Departamento de Ciências Biológicas, Universidade Federal do Triângulo Mineiro, Av. Frei Paulino 30, Uberaba, Minas Gerais, Brazil.
Acta Trop. 2009 Apr;110(1):57-64. doi: 10.1016/j.actatropica.2009.01.004.
In the present study, the molecular karyotypes of 12 KP1(+) and KP1(-) Trypanosoma rangeli strains were determined and 10 different molecular markers were hybridized to the chromosomes of the parasite, including seven obtained from T. rangeli [ubiquitin hydrolase (UH), a predicted serine/threonine protein kinase (STK), hexose transporter, hypothetical protein, three anonymous sequences] and three from Trypanosoma cruzi [ubiquitin-conjugating enzyme E2 (UBE2), ribosomal RNA methyltransferase (rRNAmtr), proteasome non-ATPase regulatory subunit 6 (PSMD6)]. Despite intraspecific variation, analysis of the karyotype profiles permitted the division of the T. rangeli strains into two groups coinciding with the KP1(+) and KP1(-) genotypes. Southern blot hybridization showed that, except for the hexose transporter probe, all other probes produced distinct patterns able to differentiate the KP1(+) and KP1(-) genotypes. The UH, STK and An-1A04 probes exclusively hybridized to the chromosomes of KP1(+) strains and can be used as markers of this group. In addition, the UBE2, rRNAmtr and PSMD6 markers, which are present in a conserved region in all trypanosomatid species sequenced so far, co-hybridized to the same T. rangeli chromosomal bands, suggesting the occurrence of gene synteny in these species. The finding of distinct molecular karyotypes in KP1(+) and KP1(-) strains of T. rangeli is noteworthy and might be used as a new approach to the study of genetic variability in this parasite. Together with the Southern blot hybridization results, these findings demonstrate that differences at the kDNA level might be associated with variations in nuclear DNA.
在本研究中，测定了12株KP1(+)和KP1(-)克氏锥虫菌株的分子核型，并将10种不同的分子标记与该寄生虫的染色体进行杂交，其中7种来自克氏锥虫[泛素水解酶（UH）、一种预测的丝氨酸/苏氨酸蛋白激酶（STK）、己糖转运蛋白、假定蛋白、三个匿名序列]，3种来自克鲁斯锥虫[泛素结合酶E2（UBE2）、核糖体RNA甲基转移酶（rRNAmtr）、蛋白酶体非ATP酶调节亚基6（PSMD6）]。尽管存在种内变异，但核型图谱分析允许将克氏锥虫菌株分为两组，与KP1(+)和KP1(-)基因型一致。Southern印迹杂交表明，除己糖转运蛋白探针外，所有其他探针产生的独特模式能够区分KP1(+)和KP1(-)基因型。UH、STK和An-1A04探针仅与KP1(+)菌株的染色体杂交，可作为该组的标记。此外，UBE2、rRNAmtr和PSMD6标记存在于迄今为止测序的所有锥虫物种的保守区域，它们共同与相同的克氏锥虫染色体带杂交，表明这些物种中存在基因同线性。在克氏锥虫的KP1(+)和KP1(-)菌株中发现不同的分子核型是值得注意的，可能作为研究该寄生虫遗传变异性的一种新方法。连同Southern印迹杂交结果，这些发现表明kDNA水平的差异可能与核DNA的变异有关。
