Abstract:
This study is about the inter- and intra-specific genetic diversity of trypanosomatids of
the genus Angomonas, and their association with Calliphoridae (blowflies) in Neotropical
and Afrotropical regions. Microscopic examination of 3,900 flies of various families,
mostly Calliphoridae, revealed that 31% of them harbored trypanosomatids. Small
subunit rRNA (SSU rRNA) barcoding showed that Angomonas predominated (46%)
over the other common trypanosomatids of blowflies of genera Herpetomonas and
Wallacemonas. Among Angomonas spp., A. deanei was much more common than
the two-other species, A. desouzai and A. ambiguus. Phylogenetic analyses based
on SSU rRNA, glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH)
and internal transcribed spacer rDNA (ITS rDNA) sequences revealed a marked
genetic diversity within A. deanei, which comprised four infraspecific genotypes (Dea1–
Dea4), and four corresponding symbiont genotypes (Kcr1–Kcr4). Host and symbiont
phylogenies were highly congruent corroborating their co-divergence, consistent with
host-symbiont interdependent metabolism and symbiont reduced genomes shaped by
a long coevolutionary history. We compared the diversity of Angomonas/symbionts from
three genera of blowflies, Lucilia, Chrysomya and Cochliomyia. A. deanei, A. desouzai,
and A. ambiguus were found in the three genera of blowflies in South America. In Africa,
A. deanei and A. ambiguus were identified in Chrysomya. The absence of A. desouzai
in Africa and its presence in Neotropical Cochliomyia and Lucilia suggests parasite
spillback of A. desouzai into Chrysomya, which was most likely introduced four decades
ago from Africa into the Neotropic. The absence of correlation between parasite diversity
and geographic and genetic distances, with identical genotypes of A. deanei found in the Neotropic and Afrotropic, is consistent with disjunct distribution due to the recent
human-mediated transoceanic dispersal of Angomonas by Chrysomya. This study
provides the most comprehensive data gathered so far on the genetic repertoires of
a genus of trypanosomatids found in flies from a wide geographical range.
