Genetic evolution and implications of the mitochondrial genomes of two
newly identified Taenia spp. in rodents from Qinghai-Tibet Plateau
Abstract
The larva of Taeniidae species can infect a wide range of mammals,
causing major public health and food safety hazards worldwide. The
Qinghai-Tibet Plateau (QTP), a biodiversity hotspot, is home to many
species of rodents, which act as the critical intermediate hosts of many
Taeniidae species. In this study, we identified two new larvae of Taenia
spp., named as T. caixuepengi and T. tianguangfui, collected from the
plateau pika (Ochotona curzoniae) and the Qinghai vole (Neodon fuscus),
respectively in QTP, and their mitochondrial genomes were sequenced and
annotated. Phylogenetic trees based on the mitochondrial genome showed
that T. caixuepengi has the closest genetic relationship with T.
pisiformis, while T. tianguangfui was contained in a monophyletic group
with T. crassiceps, T. twitchelli and T. martis. Biogeographic scenarios
analysis based on split time speculated that the speciation of T.
caixuepengi (~5.49 Mya) is due to host switching caused
by the evolution of its intermediate host. Although the reason for T.
tianguangfui (~13.11 Mya) speciation is not clear, the
analysis suggests that it should be infective to a variety of other
rodents following the evolutionary divergence time of its intermediate
host and the range of intermediate hosts of its genetically close
species. This study confirms the species diversity of Taeniidae in the
QTP, and speculates that the uplift of the QTP has not only a profound
impact on the biodiversity of plants and animals, but also that of
parasites.