The Analysis of Protein Coding Genes Suggests Monophyly ofTrypanosoma

✍ Scribed by Fernando Alvarez; Maria Noel Cortinas; Hector Musto

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 129 KB
• Volume: 5
• Category: Article
• ISSN: 1055-7903
• DOI: 10.1006/mpev.1996.0028

✦ Synopsis

exons in all nuclear protein coding genes (Donelson and We analyze evolutionary relationships among mem- Zeng, 1990).

bers of the family Trypanosomatidae, with particular

Two forms of host-protozoan relationships are emphasis on whether protein coding genes support known within the Trypanosomatidae: monogenetic paraphyly of the genus Trypanosoma. Phylogenetic retrypanosomatids, that have a single host (commonly an construction based on three different protein coding invertebrate), and digenetic trypanosomatids which genes (glyceraldehyde-3-phosphate dehydrogenase, parasitize two hosts, usually a vertebrate and an invertrypanothione reductase, and ␣-tubulin) suggests that tebrate. The former group comprises four genera: Cri-Trypanosoma is monophyletic. Moreover, pairwise thidia, Leptomonas, Herpetomonas, and Blastochricomparisons of other protein coding genes show that tidia, whereas digenetic species mainly belong to two the distances between Trypanosoma cruzi and T. brugenera: Leishmania and Trypanosoma. The latter gecei are significantly smaller than are the distances benus is rather heterogeneous and contains a very large tween each Trypanosoma species and Crithidia or number of species. The species of Trypanosoma have Leishmania. These results contradict recent published been divided in two major sections according to where phylogenies based on nuclear rRNA genes which sugthey complete their cycles in the insect-vector (Hoare, gest that T. cruzi is more closely related to Leishmania 1964): Stercoraria, whose most representative example and Crithidia than to T. brucei.