title: Phylogeny of Trypanosoma brucei and Trypanosoma evansi in naturally infected cattle in Nigeria by analysis of repetitive and ribosomal DNA sequences.
abstract: In continuing efforts to better understand the genetics of bovine trypanosomosis, we assessed genetic diversity of Trypanosoma brucei and Trypanosoma evansi in naturally infected Nigerian cattle using repetitive DNA and internal transcribed spacer 1 of rDNA sequences and compared these sequences to species from other countries. The length of repetitive DNA sequences in both species ranged from 161 to 244 bp and 239 to 240 bp for T. brucei and T. evansi, respectively, while the ITS1 rDNA sequences length range from 299 to 364 bp. The mean GC content of ITS1 rDNA sequences was 33.57 %, and that of repetitive sequences were 39.9 and 31.1 % for T. brucei and T. evansi, respectively. Result from sequence alignment revealed both T. brucei and T. evansi repetitive DNA sequences to be more polymorphic than ITS1 rDNA sequences, with moderate points of deletion and insertions. T. brucei separated into two clades when subjected to phylogenetic analysis. T. evansi repetitive DNA sequences clustered tightly within the T. brucei clade while the ITS1 rDNA sequences of T. brucei were clearly separated from T. theileri and T. vivax individually used as outgroups. This study suggest that ITS1 rDNA sequences may not be suitable for phylogenetic differentiation of the Trypanozoon group and also suggest that T. evansi may be a phenotypic variant of T. brucei which may have potential implications in designing prevention and therapeutic strategies.
authors.affiliation: Animal Genetics and Genomics Laboratory, International Programs, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA. takeetmi@funaab.edu.ng.|Department of Veterinary Microbiology and Parasitology, Federal University of Agriculture, Abeokuta, Nigeria. takeetmi@funaab.edu.ng.|Department of Veterinary Microbiology and Parasitology, University of Ibadan, Ibadan, Nigeria. takeetmi@funaab.edu.ng.
authors.forename: Michael I
authors.initials: MI
authors.lastname: Takeet
authors.affiliation: Department of Animal Science, Berry College, Mount Berry, GA, 30149, USA.|Department of Animal and Dairy sciences, University of Georgia, Athens, GA, 30602, USA.
authors.forename: Sunday O
authors.initials: SO
authors.lastname: Peters
authors.affiliation: Department of Veterinary Microbiology and Parasitology, University of Ibadan, Ibadan, Nigeria.
authors.forename: Benjamin O
authors.initials: BO
authors.lastname: Fagbemi
authors.affiliation: Animal Genetics and Genomics Laboratory, International Programs, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA.|Department of Biomedicine, Universidad de Oriente, Cumana, Venezuela.
authors.forename: Marcos
authors.initials: M
authors.lastname: De Donato
authors.affiliation: Department of Veterinary Medicine and Surgery, Federal University of Agriculture, Abeokuta, Nigeria.
authors.forename: Vivian O
authors.initials: VO
authors.lastname: Takeet
authors.affiliation: Animal Genetics and Genomics Laboratory, International Programs, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA.|Department of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Nigeria.
authors.forename: Mathew
authors.initials: M
authors.lastname: Wheto
authors.affiliation: Animal Genetics and Genomics Laboratory, International Programs, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Ikhide G
authors.initials: IG
authors.lastname: Imumorin
mesh_terms: D000818:Animals; D002417:Cattle; D016054:DNA, Protozoan / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D014644:Genetic Variation; D009549:Nigeria / Q000453:epidemiology; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D014345:Trypanosoma / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D014354:Trypanosomiasis, Bovine / Q000453:epidemiology* / Q000469:parasitology
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal
keywords: Cattle; Phylogenetics; Repetitive DNA; Ribosomal DNA sequences; Trypanosoma brucei; Trypanosoma evansi