The trypanosomatid subfamily Herpetomonadinae includes plant-pathogenic dixenous genus Phytomonas as well as two sister monoxenous genera - Herpetomonas and Lafontella. The latter one is very poorly studied with the only information on its biology being its affinity to muscid and calliforid flies and the inability to survive at elevated temperature.
To shed more light on this obscure genus and get insights into the evolution of gene content in the subfamily Herpetomonadinae, we conducted transcriptome sequencing of Lafontella sp. GMO-01 and comparative analysis of its predicted arsenal of proteins with those of other trypanosomatids.
Our results show considerable similarity between the two monoxenous genera of Herpetomonadinae in the total number of proteins, exceeding that in the majority of other trypanosomatids as well as content of functional orthogroups. Using Lafontella and Herpetomonas as the closest outgroups allowed inferring the genes uniquely lost by Phytomonas, their dixenous cousin.
The fact that GC content of Lafontella is intermediate between that of Herpetomonas and Phytomonas correlating with the phylogenetic distances separating the three genera suggests that a more thorough analysis of this flagellate can shed new light on the origin of dixeny in this subfamily.