Establishment of molecular karyotype and syntenic relationships of bat trypanosomes from Trypanosoma Cruzi clade

Abstract

The genus Trypanosoma comprises hemoflagellate parasites generally transmitted to the vertebrate host by a hematophagous arthropod. Only T. brucei gambiense and T. brucei rhodesiense in Africa and T. cruzi and T. rangeli in Americas infect humans and with the exception of T. rangeli, all of them are pathogenic. The Schizotrypanum clade (T. cruzi and T. cruzi-like) includes pathogenic and non-pathogenic trypanosomes of mammals in South America (terrestrial and bats): T. cruzi, T. cruzi marinkellei, dionisii T., T. conorhini, and other related species or subspecies (T. cruzi bat, T. rangeli-like). T. cruzi taxon is formed by isolated genetically heterogeneous distributed into seven subdivisions designated as Discrete Units Typing (DTU) including trypanosomes isolated from Brazilian bat identified as Tc bat. T. cruzi marinkellei, prevalent in bats of Central and South America, belongs to the subgenus Schizotrypanum and it has been regarded as a subspecies of T. cruzi. Trypanosoma species of bats have great interest in the evolutionary plan. Recently it was suggested that T. cruzi and T. rangeli evolved from a strain of Trypanosoma bat that later adapted to terrestrial mammals. To understand the chromosome evolution in T. cruzi we will study the chromosome organization and syntenic associations between the species of clade T. cruzi, especially those that parasitize bats. We intend to study those species whose genomes will be sequenced soon. The objectives of this project are: 1) to establish the molecular karyotype by PFGE of three species of the clade T. cruzi: T. cruzi marinkellei, T. cruzi bat and T. dionisii. T. cruzi CL Brener clone will be used as reference; 2) to define syntenic associations between these species by hybridization with linkage markers established in CL Brener clone; 3) to map the genes of the superfamily of trans-sialidases by chromoblot hybridization. Rearrangement of syntenic segments into different combinations could explain the observed polymorphism in Trypanosoma species karyotypes. We will try to find out how these rearrangements come about, and what would be the evolutionary relationships of trypanosomes of clade T. cruzi from a common ancestor. (AU)